Question: What is NodeAffinityArgs?

Answer: N o d e A f f i n i t y A r g s   h o l d s   a r g u m e n t s   t o   c o n f i g u r e   t h e   N o d e A f f i n i t y   p l u g i n .   A d d e d A f f i n i t y   i s   a p p l i e d   t o   a l l   P o d s   a d d i t i o n a l l y   t o   t h e   N o d e A f f i n i t y   s p e c i f i e d   i n   t h e   P o d S p e c .   T h a t   i s ,   N o d e s   n e e d   t o   s a t i s f y   A d d e d A f f i n i t y   A N D   . s p e c . N o d e A f f i n i t y .   A d d e d A f f i n i t y   i s   e m p t y   b y   d e f a u l t   ( a l l   N o d e s   m a t c h ) .   W h e n   A d d e d A f f i n i t y   i s   u s e d ,   s o m e   P o d s   w i t h   a f f i n i t y   r e q u i r e m e n t s   t h a t   m a t c h   a   s p e c i f i c   N o d e   ( s u c h   a s   D a e m o n s e t   P o d s )   m i g h t   r e m a i n   u n s c h e d u l a b l e .


Question: What is NodeResourcesBalancedAllocationArgs?

Answer: N o d e R e s o u r c e s B a l a n c e d A l l o c a t i o n A r g s   h o l d s   a r g u m e n t s   u s e d   t o   c o n f i g u r e   N o d e R e s o u r c e s B a l a n c e d A l l o c a t i o n   p l u g i n .   R e s o u r c e s   t o   b e   m a n a g e d ,   t h e   d e f a u l t   i s   " c p u "   a n d   " m e m o r y "   i f   n o t   s p e c i f i e d .


Question: What is NodeResourcesFitArgs?

Answer: N o d e R e s o u r c e s F i t A r g s   h o l d s   a r g u m e n t s   u s e d   t o   c o n f i g u r e   t h e   N o d e R e s o u r c e s F i t   p l u g i n .   I g n o r e d R e s o u r c e s   i s   t h e   l i s t   o f   r e s o u r c e s   t h a t   N o d e R e s o u r c e s   f i t   f i l t e r   s h o u l d   i g n o r e .   T h i s   d o e s n ' t   a p p l y   t o   s c o r i n g .   I g n o r e d R e s o u r c e G r o u p s   d e f i n e s   t h e   l i s t   o f   r e s o u r c e   g r o u p s   t h a t   N o d e R e s o u r c e s   f i t   f i l t e r   s h o u l d   i g n o r e .   e . g .   i f   g r o u p   i s   [ " e x a m p l e . c o m " ] ,   i t   w i l l   i g n o r e   a l l   r e s o u r c e   n a m e s   t h a t   b e g i n   w i t h   " e x a m p l e . c o m " ,   s u c h   a s   " e x a m p l e . c o m / a a a "   a n d   " e x a m p l e . c o m / b b b " .   A   r e s o u r c e   g r o u p   n a m e   c a n ' t   c o n t a i n   ' / ' .   T h i s   d o e s n ' t   a p p l y   t o   s c o r i n g .   S c o r i n g S t r a t e g y   s e l e c t s   t h e   n o d e   r e s o u r c e   s c o r i n g   s t r a t e g y .   T h e   d e f a u l t   s t r a t e g y   i s   L e a s t A l l o c a t e d   w i t h   a n   e q u a l   " c p u "   a n d   " m e m o r y "   w e i g h t .


Question: What is PodTopologySpreadArgs?

Answer: P o d T o p o l o g y S p r e a d A r g s   h o l d s   a r g u m e n t s   u s e d   t o   c o n f i g u r e   t h e   P o d T o p o l o g y S p r e a d   p l u g i n .   D e f a u l t C o n s t r a i n t s   d e f i n e s   t o p o l o g y   s p r e a d   c o n s t r a i n t s   t o   b e   a p p l i e d   t o   P o d s   t h a t   d o n ' t   d e f i n e   a n y   i n   p o d . s p e c . t o p o l o g y S p r e a d C o n s t r a i n t s .   . d e f a u l t C o n s t r a i n t s [ * ] . l a b e l S e l e c t o r s   m u s t   b e   e m p t y ,   a s   t h e y   a r e   d e d u c e d   f r o m   t h e   P o d ' s   m e m b e r s h i p   t o   S e r v i c e s ,   R e p l i c a t i o n C o n t r o l l e r s ,   R e p l i c a S e t s   o r   S t a t e f u l S e t s .   W h e n   n o t   e m p t y ,   . d e f a u l t i n g T y p e   m u s t   b e   " L i s t " .   D e f a u l t i n g T y p e   d e t e r m i n e s   h o w   . d e f a u l t C o n s t r a i n t s   a r e   d e d u c e d .   C a n   b e   o n e   o f   " S y s t e m "   o r   " L i s t " .   " S y s t e m " :   U s e   k u b e r n e t e s   d e f i n e d   c o n s t r a i n t s   t h a t   s p r e a d   P o d s   a m o n g   N o d e s   a n d   Z o n e s . " L i s t " :   U s e   c o n s t r a i n t s   d e f i n e d   i n   . d e f a u l t C o n s t r a i n t s .   D e f a u l t s   t o   " S y s t e m " .


Question: What is VolumeBindingArgs?

Answer: V o l u m e B i n d i n g A r g s   h o l d s   a r g u m e n t s   u s e d   t o   c o n f i g u r e   t h e   V o l u m e B i n d i n g   p l u g i n .   B i n d T i m e o u t S e c o n d s   i s   t h e   t i m e o u t   i n   s e c o n d s   i n   v o l u m e   b i n d i n g   o p e r a t i o n .   V a l u e   m u s t   b e   n o n - n e g a t i v e   i n t e g e r .   T h e   v a l u e   z e r o   i n d i c a t e s   n o   w a i t i n g .   I f   t h i s   v a l u e   i s   n i l ,   t h e   d e f a u l t   v a l u e   ( 6 0 0 )   w i l l   b e   u s e d .   S h a p e   s p e c i f i e s   t h e   p o i n t s   d e f i n i n g   t h e   s c o r e   f u n c t i o n   s h a p e ,   w h i c h   i s   u s e d   t o   s c o r e   n o d e s   b a s e d   o n   t h e   u t i l i z a t i o n   o f   p r o v i s i o n e d   P V s .   T h e   u t i l i z a t i o n   i s   c a l c u l a t e d   b y   d i v i d i n g   t h e   t o t a l   r e q u e s t e d   s t o r a g e   o f   t h e   p o d   b y   t h e   t o t a l   c a p a c i t y   o f   f e a s i b l e   P V s   o n   e a c h   n o d e .   E a c h   p o i n t   c o n t a i n s   u t i l i z a t i o n   ( r a n g e s   f r o m   0   t o   1 0 0 )   a n d   i t s   a s s o c i a t e d   s c o r e   ( r a n g e s   f r o m   0   t o   1 0 ) .   Y o u   c a n   t u r n   t h e   p r i o r i t y   b y   s p e c i f y i n g   d i f f e r e n t   s c o r e s   f o r   d i f f e r e n t   u t i l i z a t i o n   n u m b e r s .   T h e   d e f a u l t   s h a p e   p o i n t s   a r e :   1 0   f o r   0   u t i l i z a t i o n 0   f o r   1 0 0   u t i l i z a t i o n   A l l   p o i n t s   m u s t   b e   s o r t e d   i n   i n c r e a s i n g   o r d e r   b y   u t i l i z a t i o n .


Question: What is Extender?

Answer: A p p e a r s   i n :   K u b e S c h e d u l e r C o n f i g u r a t i o n   E x t e n d e r   h o l d s   t h e   p a r a m e t e r s   u s e d   t o   c o m m u n i c a t e   w i t h   t h e   e x t e n d e r .   I f   a   v e r b   i s   u n s p e c i f i e d / e m p t y ,   i t   i s   a s s u m e d   t h a t   t h e   e x t e n d e r   c h o s e   n o t   t o   p r o v i d e   t h a t   e x t e n s i o n .   U R L P r e f i x   a t   w h i c h   t h e   e x t e n d e r   i s   a v a i l a b l e   V e r b   f o r   t h e   f i l t e r   c a l l ,   e m p t y   i f   n o t   s u p p o r t e d .   T h i s   v e r b   i s   a p p e n d e d   t o   t h e   U R L P r e f i x   w h e n   i s s u i n g   t h e   f i l t e r   c a l l   t o   e x t e n d e r .   V e r b   f o r   t h e   p r e e m p t   c a l l ,   e m p t y   i f   n o t   s u p p o r t e d .   T h i s   v e r b   i s   a p p e n d e d   t o   t h e   U R L P r e f i x   w h e n   i s s u i n g   t h e   p r e e m p t   c a l l   t o   e x t e n d e r .   V e r b   f o r   t h e   p r i o r i t i z e   c a l l ,   e m p t y   i f   n o t   s u p p o r t e d .   T h i s   v e r b   i s   a p p e n d e d   t o   t h e   U R L P r e f i x   w h e n   i s s u i n g   t h e   p r i o r i t i z e   c a l l   t o   e x t e n d e r .   T h e   n u m e r i c   m u l t i p l i e r   f o r   t h e   n o d e   s c o r e s   t h a t   t h e   p r i o r i t i z e   c a l l   g e n e r a t e s .   T h e   w e i g h t   s h o u l d   b e   a   p o s i t i v e   i n t e g e r   V e r b   f o r   t h e   b i n d   c a l l ,   e m p t y   i f   n o t   s u p p o r t e d .   T h i s   v e r b   i s   a p p e n d e d   t o   t h e   U R L P r e f i x   w h e n   i s s u i n g   t h e   b i n d   c a l l   t o   e x t e n d e r .   I f   t h i s   m e t h o d   i s   i m p l e m e n t e d   b y   t h e   e x t e n d e r ,   i t   i s   t h e   e x t e n d e r ' s   r e s p o n s i b i l i t y   t o   b i n d   t h e   p o


Question: What is ExtenderManagedResource?

Answer: A p p e a r s   i n :   E x t e n d e r   E x t e n d e r M a n a g e d R e s o u r c e   d e s c r i b e s   t h e   a r g u m e n t s   o f   e x t e n d e d   r e s o u r c e s   m a n a g e d   b y   a n   e x t e n d e r .   N a m e   i s   t h e   e x t e n d e d   r e s o u r c e   n a m e .   I g n o r e d B y S c h e d u l e r   i n d i c a t e s   w h e t h e r   k u b e - s c h e d u l e r   s h o u l d   i g n o r e   t h i s   r e s o u r c e   w h e n   a p p l y i n g   p r e d i c a t e s .


Question: What is ExtenderTLSConfig?

Answer: A p p e a r s   i n :   E x t e n d e r   E x t e n d e r T L S C o n f i g   c o n t a i n s   s e t t i n g s   t o   e n a b l e   T L S   w i t h   e x t e n d e r   S e r v e r   s h o u l d   b e   a c c e s s e d   w i t h o u t   v e r i f y i n g   t h e   T L S   c e r t i f i c a t e .   F o r   t e s t i n g   o n l y .   S e r v e r N a m e   i s   p a s s e d   t o   t h e   s e r v e r   f o r   S N I   a n d   i s   u s e d   i n   t h e   c l i e n t   t o   c h e c k   s e r v e r   c e r t i f i c a t e s   a g a i n s t .   I f   S e r v e r N a m e   i s   e m p t y ,   t h e   h o s t n a m e   u s e d   t o   c o n t a c t   t h e   s e r v e r   i s   u s e d .   S e r v e r   r e q u i r e s   T L S   c l i e n t   c e r t i f i c a t e   a u t h e n t i c a t i o n   S e r v e r   r e q u i r e s   T L S   c l i e n t   c e r t i f i c a t e   a u t h e n t i c a t i o n   T r u s t e d   r o o t   c e r t i f i c a t e s   f o r   s e r v e r   C e r t D a t a   h o l d s   P E M - e n c o d e d   b y t e s   ( t y p i c a l l y   r e a d   f r o m   a   c l i e n t   c e r t i f i c a t e   f i l e ) .   C e r t D a t a   t a k e s   p r e c e d e n c e   o v e r   C e r t F i l e   K e y D a t a   h o l d s   P E M - e n c o d e d   b y t e s   ( t y p i c a l l y   r e a d   f r o m   a   c l i e n t   c e r t i f i c a t e   k e y   f i l e ) .   K e y D a t a   t a k e s   p r e c e d e n c e   o v e r   K e y F i l e   C A D a t a   h o l d s   P E M - e n c o d e d   b y t e s   ( t y p i c a l l y   r e a d   f r o m   a   r o o t   c e r t i f i c a t e s   b u n d l e ) .   C A D a t a   t a k e s   p r e c e d e n c e   o v e r   C A F i l e


Question: What is KubeSchedulerProfile?

Answer: A p p e a r s   i n :   K u b e S c h e d u l e r C o n f i g u r a t i o n   K u b e S c h e d u l e r P r o f i l e   i s   a   s c h e d u l i n g   p r o f i l e .   S c h e d u l e r N a m e   i s   t h e   n a m e   o f   t h e   s c h e d u l e r   a s s o c i a t e d   t o   t h i s   p r o f i l e .   I f   S c h e d u l e r N a m e   m a t c h e s   w i t h   t h e   p o d ' s   " s p e c . s c h e d u l e r N a m e " ,   t h e n   t h e   p o d   i s   s c h e d u l e d   w i t h   t h i s   p r o f i l e .   P e r c e n t a g e O f N o d e s T o S c o r e   i s   t h e   p e r c e n t a g e   o f   a l l   n o d e s   t h a t   o n c e   f o u n d   f e a s i b l e   f o r   r u n n i n g   a   p o d ,   t h e   s c h e d u l e r   s t o p s   i t s   s e a r c h   f o r   m o r e   f e a s i b l e   n o d e s   i n   t h e   c l u s t e r .   T h i s   h e l p s   i m p r o v e   s c h e d u l e r ' s   p e r f o r m a n c e .   S c h e d u l e r   a l w a y s   t r i e s   t o   f i n d   a t   l e a s t   " m i n F e a s i b l e N o d e s T o F i n d "   f e a s i b l e   n o d e s   n o   m a t t e r   w h a t   t h e   v a l u e   o f   t h i s   f l a g   i s .   E x a m p l e :   i f   t h e   c l u s t e r   s i z e   i s   5 0 0   n o d e s   a n d   t h e   v a l u e   o f   t h i s   f l a g   i s   3 0 ,   t h e n   s c h e d u l e r   s t o p s   f i n d i n g   f u r t h e r   f e a s i b l e   n o d e s   o n c e   i t   f i n d s   1 5 0   f e a s i b l e   o n e s .   W h e n   t h e   v a l u e   i s   0 ,   d e f a u l t   p e r c e n t a g e   ( 5 % - - 5 0 %   b a s e d   o n   t h e   s i z e   o f   t h e   c l u s t e r )   o f   t h e   n o d e s   w i l l   b e   s c o r e d .   I t   w i l l   o v e r r i d e   g l o b a l   P e r c e n t a g e O f N o d e s T o S c o r e .   I f   i t   i s   e m p t y ,   g l o b a l   P e r c e n t a g e O f N o d e s T o S c o r e   w i l l   b e   u s e d .   P l u g i n s   s p e c i f y


Question: What is Plugin?

Answer: A p p e a r s   i n :   P l u g i n S e t   P l u g i n   s p e c i f i e s   a   p l u g i n   n a m e   a n d   i t s   w e i g h t   w h e n   a p p l i c a b l e .   W e i g h t   i s   u s e d   o n l y   f o r   S c o r e   p l u g i n s .   N a m e   d e f i n e s   t h e   n a m e   o f   p l u g i n   W e i g h t   d e f i n e s   t h e   w e i g h t   o f   p l u g i n ,   o n l y   u s e d   f o r   S c o r e   p l u g i n s .


Question: What is PluginConfig?

Answer: A p p e a r s   i n :   K u b e S c h e d u l e r P r o f i l e   P l u g i n C o n f i g   s p e c i f i e s   a r g u m e n t s   t h a t   s h o u l d   b e   p a s s e d   t o   a   p l u g i n   a t   t h e   t i m e   o f   i n i t i a l i z a t i o n .   A   p l u g i n   t h a t   i s   i n v o k e d   a t   m u l t i p l e   e x t e n s i o n   p o i n t s   i s   i n i t i a l i z e d   o n c e .   A r g s   c a n   h a v e   a r b i t r a r y   s t r u c t u r e .   I t   i s   u p   t o   t h e   p l u g i n   t o   p r o c e s s   t h e s e   A r g s .   N a m e   d e f i n e s   t h e   n a m e   o f   p l u g i n   b e i n g   c o n f i g u r e d   A r g s   d e f i n e s   t h e   a r g u m e n t s   p a s s e d   t o   t h e   p l u g i n s   a t   t h e   t i m e   o f   i n i t i a l i z a t i o n .   A r g s   c a n   h a v e   a r b i t r a r y   s t r u c t u r e .


Question: What is PluginSet?

Answer: A p p e a r s   i n :   P l u g i n s   P l u g i n S e t   s p e c i f i e s   e n a b l e d   a n d   d i s a b l e d   p l u g i n s   f o r   a n   e x t e n s i o n   p o i n t .   I f   a n   a r r a y   i s   e m p t y ,   m i s s i n g ,   o r   n i l ,   d e f a u l t   p l u g i n s   a t   t h a t   e x t e n s i o n   p o i n t   w i l l   b e   u s e d .   E n a b l e d   s p e c i f i e s   p l u g i n s   t h a t   s h o u l d   b e   e n a b l e d   i n   a d d i t i o n   t o   d e f a u l t   p l u g i n s .   I f   t h e   d e f a u l t   p l u g i n   i s   a l s o   c o n f i g u r e d   i n   t h e   s c h e d u l e r   c o n f i g   f i l e ,   t h e   w e i g h t   o f   p l u g i n   w i l l   b e   o v e r r i d d e n   a c c o r d i n g l y .   T h e s e   a r e   c a l l e d   a f t e r   d e f a u l t   p l u g i n s   a n d   i n   t h e   s a m e   o r d e r   s p e c i f i e d   h e r e .   D i s a b l e d   s p e c i f i e s   d e f a u l t   p l u g i n s   t h a t   s h o u l d   b e   d i s a b l e d .   W h e n   a l l   d e f a u l t   p l u g i n s   n e e d   t o   b e   d i s a b l e d ,   a n   a r r a y   c o n t a i n i n g   o n l y   o n e   " * "   s h o u l d   b e   p r o v i d e d .


Question: What is Plugins?

Answer: A p p e a r s   i n :   K u b e S c h e d u l e r P r o f i l e   P l u g i n s   i n c l u d e   m u l t i p l e   e x t e n s i o n   p o i n t s .   W h e n   s p e c i f i e d ,   t h e   l i s t   o f   p l u g i n s   f o r   a   p a r t i c u l a r   e x t e n s i o n   p o i n t   a r e   t h e   o n l y   o n e s   e n a b l e d .   I f   a n   e x t e n s i o n   p o i n t   i s   o m i t t e d   f r o m   t h e   c o n f i g ,   t h e n   t h e   d e f a u l t   s e t   o f   p l u g i n s   i s   u s e d   f o r   t h a t   e x t e n s i o n   p o i n t .   E n a b l e d   p l u g i n s   a r e   c a l l e d   i n   t h e   o r d e r   s p e c i f i e d   h e r e ,   a f t e r   d e f a u l t   p l u g i n s .   I f   t h e y   n e e d   t o   b e   i n v o k e d   b e f o r e   d e f a u l t   p l u g i n s ,   d e f a u l t   p l u g i n s   m u s t   b e   d i s a b l e d   a n d   r e - e n a b l e d   h e r e   i n   d e s i r e d   o r d e r .   P r e E n q u e u e   i s   a   l i s t   o f   p l u g i n s   t h a t   s h o u l d   b e   i n v o k e d   b e f o r e   a d d i n g   p o d s   t o   t h e   s c h e d u l i n g   q u e u e .   Q u e u e S o r t   i s   a   l i s t   o f   p l u g i n s   t h a t   s h o u l d   b e   i n v o k e d   w h e n   s o r t i n g   p o d s   i n   t h e   s c h e d u l i n g   q u e u e .   P r e F i l t e r   i s   a   l i s t   o f   p l u g i n s   t h a t   s h o u l d   b e   i n v o k e d   a t   " P r e F i l t e r "   e x t e n s i o n   p o i n t   o f   t h e   s c h e d u l i n g   f r a m e w o r k .   F i l t e r   i s   a   l i s t   o f   p l u g i n s   t h a t   s h o u l d   b e   i n v o k e d   w h e n   f i l t e r i n g   o u t   n o d e s   t h a t   c a n n o t   r u n   t h e   P o d .   P o s t F i l t e r   i s   a   l i s t   o f   p l u g i n s   t h a t   a r e   i n v o k e d   a f t e r   f i l t e r i n g   p h a s e ,   b u t   o n l y   w h e n   n o   f e a s i b l e   n o


Question: What is PodTopologySpreadConstraintsDefaulting?

Answer: ( A l i a s   o f   s t r i n g )   A p p e a r s   i n :   P o d T o p o l o g y S p r e a d A r g s   P o d T o p o l o g y S p r e a d C o n s t r a i n t s D e f a u l t i n g   d e f i n e s   h o w   t o   s e t   d e f a u l t   c o n s t r a i n t s   f o r   t h e   P o d T o p o l o g y S p r e a d   p l u g i n .


Question: What is RequestedToCapacityRatioParam?

Answer: A p p e a r s   i n :   S c o r i n g S t r a t e g y   R e q u e s t e d T o C a p a c i t y R a t i o P a r a m   d e f i n e   R e q u e s t e d T o C a p a c i t y R a t i o   p a r a m e t e r s   S h a p e   i s   a   l i s t   o f   p o i n t s   d e f i n i n g   t h e   s c o r i n g   f u n c t i o n   s h a p e .


Question: What is ResourceSpec?

Answer: A p p e a r s   i n :   N o d e R e s o u r c e s B a l a n c e d A l l o c a t i o n A r g s S c o r i n g S t r a t e g y   N o d e R e s o u r c e s B a l a n c e d A l l o c a t i o n A r g s   S c o r i n g S t r a t e g y   R e s o u r c e S p e c   r e p r e s e n t s   a   s i n g l e   r e s o u r c e .   N a m e   o f   t h e   r e s o u r c e .   W e i g h t   o f   t h e   r e s o u r c e .


Question: What is ScoringStrategy?

Answer: A p p e a r s   i n :   N o d e R e s o u r c e s F i t A r g s   S c o r i n g S t r a t e g y   d e f i n e   S c o r i n g S t r a t e g y T y p e   f o r   n o d e   r e s o u r c e   p l u g i n   T y p e   s e l e c t s   w h i c h   s t r a t e g y   t o   r u n .   R e s o u r c e s   t o   c o n s i d e r   w h e n   s c o r i n g .   T h e   d e f a u l t   r e s o u r c e   s e t   i n c l u d e s   " c p u "   a n d   " m e m o r y "   w i t h   a n   e q u a l   w e i g h t .   A l l o w e d   w e i g h t s   g o   f r o m   1   t o   1 0 0 .   W e i g h t   d e f a u l t s   t o   1   i f   n o t   s p e c i f i e d   o r   e x p l i c i t l y   s e t   t o   0 .   A r g u m e n t s   s p e c i f i c   t o   R e q u e s t e d T o C a p a c i t y R a t i o   s t r a t e g y .


Question: What is ScoringStrategyType?

Answer: ( A l i a s   o f   s t r i n g )   A p p e a r s   i n :   S c o r i n g S t r a t e g y   S c o r i n g S t r a t e g y T y p e   t h e   t y p e   o f   s c o r i n g   s t r a t e g y   u s e d   i n   N o d e R e s o u r c e s F i t   p l u g i n .


Question: What is UtilizationShapePoint?

Answer: A p p e a r s   i n :   V o l u m e B i n d i n g A r g s R e q u e s t e d T o C a p a c i t y R a t i o P a r a m   V o l u m e B i n d i n g A r g s   R e q u e s t e d T o C a p a c i t y R a t i o P a r a m   U t i l i z a t i o n S h a p e P o i n t   r e p r e s e n t s   s i n g l e   p o i n t   o f   p r i o r i t y   f u n c t i o n   s h a p e .   U t i l i z a t i o n   ( x   a x i s ) .   V a l i d   v a l u e s   a r e   0   t o   1 0 0 .   F u l l y   u t i l i z e d   n o d e   m a p s   t o   1 0 0 .   S c o r e   a s s i g n e d   t o   g i v e n   u t i l i z a t i o n   ( y   a x i s ) .   V a l i d   v a l u e s   a r e   0   t o   1 0 .   T h i s   p a g e   i s   a u t o m a t i c a l l y   g e n e r a t e d .   I f   y o u   p l a n   t o   r e p o r t   a n   i s s u e   w i t h   t h i s   p a g e ,   m e n t i o n   t h a t   t h e   p a g e   i s   a u t o - g e n e r a t e d   i n   y o u r   i s s u e   d e s c r i p t i o n .   T h e   f i x   m a y   n e e d   t o   h a p p e n   e l s e w h e r e   i n   t h e   K u b e r n e t e s   p r o j e c t .


Question: What is Configuring each kubelet in your cluster using kubeadm?

Answer: Configuring each kubelet in your cluster using kubeadmNote: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details.FEATURE STATE: Kubernetes v1.11 [stable]The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.Since the kubelet is a daemon, it needs to be maintained by some kind of an init system or service manager. When the kubelet is installed using DEBs or RPMs, systemd is configured to manage the kubelet. You can use a different service manager instead, but you need to configure it manually.Some kubelet configuration details need to be the same across all kubelets involved in the cluster, while other configuration aspects need to be set on a per-kubelet basis to accommodate the different characteristics of a given machine (such as OS, storage, and networking). You can manage the configuration of your kubelets manually, but kubeadm now provides a KubeletConfiguration API type for managing your kubelet configurations centrally.Kubelet configuration patternsThe following sections describe patterns to kubelet configuration that are simplified by using kubeadm, rather than managing the kubelet configuration for each Node manually.Propagating cluster-level configuration to each kubeletYou can provide the kubelet with default values to be used by kubeadm init and kubeadm join commands. Interesting examples include using a different container runtime or setting the default subnet used by services.If you want your services to use the subnet 10.96.0.0/12 as the default for services, you can pass the --service-cidr parameter to kubeadm:kubeadm init --service-cidr 10.96.0.0/12 Virtual IPs for services are now allocated from this subnet. You also need to set the DNS address used by the kubelet, using the --cluster-dns flag. This setting needs to be the same for every kubelet on every manager and Node in the cluster. The kubelet provides a versioned, structured API object that can configure most parameters in the kubelet and push out this configuration to each running kubelet in the cluster. This object is called KubeletConfiguration. The KubeletConfiguration allows the user to specify flags such as the cluster DNS IP addresses expressed as a list of values to a camelCased key, illustrated by the following example:apiVersion: kubelet.config.k8s.io/v1beta1 kind: KubeletConfiguration clusterDNS: - 10.96.0.10 For more details on the KubeletConfiguration have a look at this section.Providing instance-specific configuration detailsSome hosts require specific kubelet configurations due to differences in hardware, operating system, networking, or other host-specific parameters. The following list provides a few examples.The path to the DNS resolution file, as speci


Question: How does Configuring each kubelet in your cluster using kubeadm work?

Answer: Configuring each kubelet in your cluster using kubeadmNote: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details.FEATURE STATE: Kubernetes v1.11 [stable]The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.Since the kubelet is a daemon, it needs to be maintained by some kind of an init system or service manager. When the kubelet is installed using DEBs or RPMs, systemd is configured to manage the kubelet. You can use a different service manager instead, but you need to configure it manually.Some kubelet configuration details need to be the same across all kubelets involved in the cluster, while other configuration aspects need to be set on a per-kubelet basis to accommodate the different characteristics of a given machine (such as OS, storage, and networking). You can manage the configuration of your kubelets manually, but kubeadm now provides a KubeletConfiguration API type for managing your kubelet configurations centrally.Kubelet configuration patternsThe following sections describe patterns to kubelet configuration that are simplified by using kubeadm, rather than managing the kubelet configuration for each Node manually.Propagating cluster-level configuration to each kubeletYou can provide the kubelet with default values to be used by kubeadm init and kubeadm join commands. Interesting examples include using a different container runtime or setting the default subnet used by services.If you want your services to use the subnet 10.96.0.0/12 as the default for services, you can pass the --service-cidr parameter to kubeadm:kubeadm init --service-cidr 10.96.0.0/12 Virtual IPs for services are now allocated from this subnet. You also need to set the DNS address used by the kubelet, using the --cluster-dns flag. This setting needs to be the same for every kubelet on every manager and Node in the cluster. The kubelet provides a versioned, structured API object that can configure most parameters in the kubelet and push out this configuration to each running kubelet in the cluster. This object is called KubeletConfiguration. The KubeletConfiguration allows the user to specify flags such as the cluster DNS IP addresses expressed as a list of values to a camelCased key, illustrated by the following example:apiVersion: kubelet.config.k8s.io/v1beta1 kind: KubeletConfiguration clusterDNS: - 10.96.0.10 For more details on the KubeletConfiguration have a look at this section.Providing instance-specific configuration detailsSome hosts require specific kubelet configurations due to differences in hardware, operating system, networking, or other host-specific parameters. The following list provides a few examples.The path to the DNS resolution file, as speci


Question: When would you use Configuring each kubelet in your cluster using kubeadm?

Answer: Configuring each kubelet in your cluster using kubeadmNote: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details.FEATURE STATE: Kubernetes v1.11 [stable]The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.Since the kubelet is a daemon, it needs to be maintained by some kind of an init system or service manager. When the kubelet is installed using DEBs or RPMs, systemd is configured to manage the kubelet. You can use a different service manager instead, but you need to configure it manually.Some kubelet configuration details need to be the same across all kubelets involved in the cluster, while other configuration aspects need to be set on a per-kubelet basis to accommodate the different characteristics of a given machine (such as OS, storage, and networking). You can manage the configuration of your kubelets manually, but kubeadm now provides a KubeletConfiguration API type for managing your kubelet configurations centrally.Kubelet configuration patternsThe following sections describe patterns to kubelet configuration that are simplified by using kubeadm, rather than managing the kubelet configuration for each Node manually.Propagating cluster-level configuration to each kubeletYou can provide the kubelet with default values to be used by kubeadm init and kubeadm join commands. Interesting examples include using a different container runtime or setting the default subnet used by services.If you want your services to use the subnet 10.96.0.0/12 as the default for services, you can pass the --service-cidr parameter to kubeadm:kubeadm init --service-cidr 10.96.0.0/12 Virtual IPs for services are now allocated from this subnet. You also need to set the DNS address used by the kubelet, using the --cluster-dns flag. This setting needs to be the same for every kubelet on every manager and Node in the cluster. The kubelet provides a versioned, structured API object that can configure most parameters in the kubelet and push out this configuration to each running kubelet in the cluster. This object is called KubeletConfiguration. The KubeletConfiguration allows the user to specify flags such as the cluster DNS IP addresses expressed as a list of values to a camelCased key, illustrated by the following example:apiVersion: kubelet.config.k8s.io/v1beta1 kind: KubeletConfiguration clusterDNS: - 10.96.0.10 For more details on the KubeletConfiguration have a look at this section.Providing instance-specific configuration detailsSome hosts require specific kubelet configurations due to differences in hardware, operating system, networking, or other host-specific parameters. The following list provides a few examples.The path to the DNS resolution file, as speci


Question: What are the benefits of Configuring each kubelet in your cluster using kubeadm?

Answer: Configuring each kubelet in your cluster using kubeadmNote: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details.FEATURE STATE: Kubernetes v1.11 [stable]The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.Since the kubelet is a daemon, it needs to be maintained by some kind of an init system or service manager. When the kubelet is installed using DEBs or RPMs, systemd is configured to manage the kubelet. You can use a different service manager instead, but you need to configure it manually.Some kubelet configuration details need to be the same across all kubelets involved in the cluster, while other configuration aspects need to be set on a per-kubelet basis to accommodate the different characteristics of a given machine (such as OS, storage, and networking). You can manage the configuration of your kubelets manually, but kubeadm now provides a KubeletConfiguration API type for managing your kubelet configurations centrally.Kubelet configuration patternsThe following sections describe patterns to kubelet configuration that are simplified by using kubeadm, rather than managing the kubelet configuration for each Node manually.Propagating cluster-level configuration to each kubeletYou can provide the kubelet with default values to be used by kubeadm init and kubeadm join commands. Interesting examples include using a different container runtime or setting the default subnet used by services.If you want your services to use the subnet 10.96.0.0/12 as the default for services, you can pass the --service-cidr parameter to kubeadm:kubeadm init --service-cidr 10.96.0.0/12 Virtual IPs for services are now allocated from this subnet. You also need to set the DNS address used by the kubelet, using the --cluster-dns flag. This setting needs to be the same for every kubelet on every manager and Node in the cluster. The kubelet provides a versioned, structured API object that can configure most parameters in the kubelet and push out this configuration to each running kubelet in the cluster. This object is called KubeletConfiguration. The KubeletConfiguration allows the user to specify flags such as the cluster DNS IP addresses expressed as a list of values to a camelCased key, illustrated by the following example:apiVersion: kubelet.config.k8s.io/v1beta1 kind: KubeletConfiguration clusterDNS: - 10.96.0.10 For more details on the KubeletConfiguration have a look at this section.Providing instance-specific configuration detailsSome hosts require specific kubelet configurations due to differences in hardware, operating system, networking, or other host-specific parameters. The following list provides a few examples.The path to the DNS resolution file, as speci


Question: What is Configuring each kubelet in your cluster using kubeadm?

Answer: T h e   l i f e c y c l e   o f   t h e   k u b e a d m   C L I   t o o l   i s   d e c o u p l e d   f r o m   t h e   k u b e l e t ,   w h i c h   i s   a   d a e m o n   t h a t   r u n s   o n   e a c h   n o d e   w i t h i n   t h e   K u b e r n e t e s   c l u s t e r .   T h e   k u b e a d m   C L I   t o o l   i s   e x e c u t e d   b y   t h e   u s e r   w h e n   K u b e r n e t e s   i s   i n i t i a l i z e d   o r   u p g r a d e d ,   w h e r e a s   t h e   k u b e l e t   i s   a l w a y s   r u n n i n g   i n   t h e   b a c k g r o u n d .   S i n c e   t h e   k u b e l e t   i s   a   d a e m o n ,   i t   n e e d s   t o   b e   m a i n t a i n e d   b y   s o m e   k i n d   o f   a n   i n i t   s y s t e m   o r   s e r v i c e   m a n a g e r .   W h e n   t h e   k u b e l e t   i s   i n s t a l l e d   u s i n g   D E B s   o r   R P M s ,   s y s t e m d   i s   c o n f i g u r e d   t o   m a n a g e   t h e   k u b e l e t .   Y o u   c a n   u s e   a   d i f f e r e n t   s e r v i c e   m a n a g e r   i n s t e a d ,   b u t   y o u   n e e d   t o   c o n f i g u r e   i t   m a n u a l l y .   S o m e   k u b e l e t   c o n f i g u r a t i o n   d e t a i l s   n e e d   t o   b e   t h e   s a m e   a c r o s s   a l l   k u b e l e t s   i n v o l v e d   i n   t h e   c l u s t e r ,   w h i l e   o t h e r   c o n f i g u r a t i o n   a s p e c t s   n e e d   t o   b e   s e t   o n   a   p e r - k u b e l e t   b a s i s   t o   a c c o m m o d a t e   t h e   d i f f e r e n t   c h a r a c t e r i s t i c s   o f   a   g i v e n   m a c h i n e   ( s u c h   a s   O S ,   s t o r a g e ,   a n d   n e t w o r k i n g ) .   Y o u   c a n   m a n a g e   t h e   c o n f i g u r a t i o n   o f   y o u r   k u b e l e t s   m a n u a l l y ,   b u t   k u b e a d m   n o w   p r o v i d e s   a   K u b e l e t C o n f i g u r a t i o n   A P I   t y p e   f o r   m a n a g i n g   y o u r   k u b e l e t   c o n f


Question: What is Kubelet configuration patterns?

Answer: T h e   f o l l o w i n g   s e c t i o n s   d e s c r i b e   p a t t e r n s   t o   k u b e l e t   c o n f i g u r a t i o n   t h a t   a r e   s i m p l i f i e d   b y   u s i n g   k u b e a d m ,   r a t h e r   t h a n   m a n a g i n g   t h e   k u b e l e t   c o n f i g u r a t i o n   f o r   e a c h   N o d e   m a n u a l l y .


Question: What is Propagating cluster-level configuration to each kubelet?

Answer: Y o u   c a n   p r o v i d e   t h e   k u b e l e t   w i t h   d e f a u l t   v a l u e s   t o   b e   u s e d   b y   k u b e a d m   i n i t   a n d   k u b e a d m   j o i n   c o m m a n d s .   I n t e r e s t i n g   e x a m p l e s   i n c l u d e   u s i n g   a   d i f f e r e n t   c o n t a i n e r   r u n t i m e   o r   s e t t i n g   t h e   d e f a u l t   s u b n e t   u s e d   b y   s e r v i c e s .   I f   y o u   w a n t   y o u r   s e r v i c e s   t o   u s e   t h e   s u b n e t   1 0 . 9 6 . 0 . 0 / 1 2   a s   t h e   d e f a u l t   f o r   s e r v i c e s ,   y o u   c a n   p a s s   t h e   - - s e r v i c e - c i d r   p a r a m e t e r   t o   k u b e a d m :   k u b e a d m   i n i t   - - s e r v i c e - c i d r   1 0 . 9 6 . 0 . 0 / 1 2   V i r t u a l   I P s   f o r   s e r v i c e s   a r e   n o w   a l l o c a t e d   f r o m   t h i s   s u b n e t .   Y o u   a l s o   n e e d   t o   s e t   t h e   D N S   a d d r e s s   u s e d   b y   t h e   k u b e l e t ,   u s i n g   t h e   - - c l u s t e r - d n s   f l a g .   T h i s   s e t t i n g   n e e d s   t o   b e   t h e   s a m e   f o r   e v e r y   k u b e l e t   o n   e v e r y   m a n a g e r   a n d   N o d e   i n   t h e   c l u s t e r .   T h e   k u b e l e t   p r o v i d e s   a   v e r s i o n e d ,   s t r u c t u r e d   A P I   o b j e c t   t h a t   c a n   c o n f i g u r e   m o s t   p a r a m e t e r s   i n   t h e   k u b e l e t   a n d   p u s h   o u t   t h i s   c o n f i g u r a t i o n   t o   e a c h   r u n n i n g   k u b e l e t   i n   t h e   c l u s t e r .   T h i s   o b j e c t   i s   c a l l e d   K u b e l e t C o n f i g u r a t i o n .   T h e   K u b e l e t C o n f i g u r a t i o n   a l l o w s   t h e   u s e r   t o   s p e c i f y   f l a g s   s u c h   a s   t h e   c l u s t e r   D N S   I P   a d d r e s s e s   e x p r e s s e d   a s   a   l i s t   o f   v a l u e s   t o   a   c a m e l C a s e


Question: What is Providing instance-specific configuration details?

Answer: S o m e   h o s t s   r e q u i r e   s p e c i f i c   k u b e l e t   c o n f i g u r a t i o n s   d u e   t o   d i f f e r e n c e s   i n   h a r d w a r e ,   o p e r a t i n g   s y s t e m ,   n e t w o r k i n g ,   o r   o t h e r   h o s t - s p e c i f i c   p a r a m e t e r s .   T h e   f o l l o w i n g   l i s t   p r o v i d e s   a   f e w   e x a m p l e s .   T h e   p a t h   t o   t h e   D N S   r e s o l u t i o n   f i l e ,   a s   s p e c i f i e d   b y   t h e   - - r e s o l v - c o n f   k u b e l e t   c o n f i g u r a t i o n   f l a g ,   m a y   d i f f e r   a m o n g   o p e r a t i n g   s y s t e m s ,   o r   d e p e n d i n g   o n   w h e t h e r   y o u   a r e   u s i n g   s y s t e m d - r e s o l v e d .   I f   t h i s   p a t h   i s   w r o n g ,   D N S   r e s o l u t i o n   w i l l   f a i l   o n   t h e   N o d e   w h o s e   k u b e l e t   i s   c o n f i g u r e d   i n c o r r e c t l y . T h e   N o d e   A P I   o b j e c t   . m e t a d a t a . n a m e   i s   s e t   t o   t h e   m a c h i n e ' s   h o s t n a m e   b y   d e f a u l t ,   u n l e s s   y o u   a r e   u s i n g   a   c l o u d   p r o v i d e r .   Y o u   c a n   u s e   t h e   - - h o s t n a m e - o v e r r i d e   f l a g   t o   o v e r r i d e   t h e   d e f a u l t   b e h a v i o r   i f   y o u   n e e d   t o   s p e c i f y   a   N o d e   n a m e   d i f f e r e n t   f r o m   t h e   m a c h i n e ' s   h o s t n a m e . C u r r e n t l y ,   t h e   k u b e l e t   c a n n o t   a u t o m a t i c a l l y   d e t e c t   t h e   c g r o u p   d r i v e r   u s e d   b y   t h e   c o n t a i n e r   r u n t i m e ,   b u t   t h e   v a l u e   o f   - - c g r o u p - d r i v e r   m u s t   m a t c h   t h e   c g r o u p   d r i v e r   u s e d   b y   t h e   c o n t a i n e r   r u n t i m e   t o   e n s u r e   t h e   h e a l t h   o f   t h e   k u b e l e t . T o   s p e c i f y   t h e   c o n t a i n e


Question: What is Configure kubelets using kubeadm?

Answer: I t   i s   p o s s i b l e   t o   c o n f i g u r e   t h e   k u b e l e t   t h a t   k u b e a d m   w i l l   s t a r t   i f   a   c u s t o m   K u b e l e t C o n f i g u r a t i o n   A P I   o b j e c t   i s   p a s s e d   w i t h   a   c o n f i g u r a t i o n   f i l e   l i k e   s o   k u b e a d m   . . .   - - c o n f i g   s o m e - c o n f i g - f i l e . y a m l .   B y   c a l l i n g   k u b e a d m   c o n f i g   p r i n t   i n i t - d e f a u l t s   - - c o m p o n e n t - c o n f i g s   K u b e l e t C o n f i g u r a t i o n   y o u   c a n   s e e   a l l   t h e   d e f a u l t   v a l u e s   f o r   t h i s   s t r u c t u r e .   I t   i s   a l s o   p o s s i b l e   t o   a p p l y   i n s t a n c e - s p e c i f i c   p a t c h e s   o v e r   t h e   b a s e   K u b e l e t C o n f i g u r a t i o n .   H a v e   a   l o o k   a t   C u s t o m i z i n g   t h e   k u b e l e t   f o r   m o r e   d e t a i l s .


Question: What is Workflow when using kubeadm init?

Answer: W h e n   y o u   c a l l   k u b e a d m   i n i t ,   t h e   k u b e l e t   c o n f i g u r a t i o n   i s   m a r s h a l l e d   t o   d i s k   a t   / v a r / l i b / k u b e l e t / c o n f i g . y a m l ,   a n d   a l s o   u p l o a d e d   t o   a   k u b e l e t - c o n f i g   C o n f i g M a p   i n   t h e   k u b e - s y s t e m   n a m e s p a c e   o f   t h e   c l u s t e r .   A d d i t i o n a l l y ,   t h e   k u b e a d m   t o o l   d e t e c t s   t h e   C R I   s o c k e t   o n   t h e   n o d e   a n d   w r i t e s   i t s   d e t a i l s   ( i n c l u d i n g   t h e   s o c k e t   p a t h )   i n t o   a   l o c a l   c o n f i g u r a t i o n ,   / v a r / l i b / k u b e l e t / i n s t a n c e - c o n f i g . y a m l .   A   k u b e l e t   c o n f i g u r a t i o n   f i l e   i s   a l s o   w r i t t e n   t o   / e t c / k u b e r n e t e s / k u b e l e t . c o n f   w i t h   t h e   b a s e l i n e   c l u s t e r - w i d e   c o n f i g u r a t i o n   f o r   a l l   k u b e l e t s   i n   t h e   c l u s t e r .   T h i s   c o n f i g u r a t i o n   f i l e   p o i n t s   t o   t h e   c l i e n t   c e r t i f i c a t e s   t h a t   a l l o w   t h e   k u b e l e t   t o   c o m m u n i c a t e   w i t h   t h e   A P I   s e r v e r .   T h i s   a d d r e s s e s   t h e   n e e d   t o   p r o p a g a t e   c l u s t e r - l e v e l   c o n f i g u r a t i o n   t o   e a c h   k u b e l e t .   T o   a d d r e s s   t h e   s e c o n d   p a t t e r n   o f   p r o v i d i n g   i n s t a n c e - s p e c i f i c   c o n f i g u r a t i o n   d e t a i l s ,   k u b e a d m   w r i t e s   a n   e n v i r o n m e n t   f i l e   t o   / v a r / l i b / k u b e l e t / k u b e a d m - f l a g s . e n v ,   w h i c h   c o n t a i n s   a   l i s t   o f   f l a g s   t o   p a s s   t o   t h e   k u b e l e t   w h e n   i t   s t a r t s .   T h e   f l a g s   a r e   p r e s e n t e d   i n   t h e   f


Question: What is Workflow when using kubeadm join?

Answer: W h e n   y o u   r u n   k u b e a d m   j o i n ,   k u b e a d m   u s e s   t h e   B o o t s t r a p   T o k e n   c r e d e n t i a l   t o   p e r f o r m   a   T L S   b o o t s t r a p ,   w h i c h   f e t c h e s   t h e   c r e d e n t i a l   n e e d e d   t o   d o w n l o a d   t h e   k u b e l e t - c o n f i g   C o n f i g M a p   a n d   w r i t e s   i t   t o   / v a r / l i b / k u b e l e t / c o n f i g . y a m l .   A d d i t i o n a l l y ,   t h e   k u b e a d m   t o o l   d e t e c t s   t h e   C R I   s o c k e t   o n   t h e   n o d e   a n d   w r i t e s   i t s   d e t a i l s   ( i n c l u d i n g   t h e   s o c k e t   p a t h )   i n t o   a   l o c a l   c o n f i g u r a t i o n ,   / v a r / l i b / k u b e l e t / i n s t a n c e - c o n f i g . y a m l .   T h e   d y n a m i c   e n v i r o n m e n t   f i l e   i s   g e n e r a t e d   i n   e x a c t l y   t h e   s a m e   w a y   a s   k u b e a d m   i n i t .   N e x t ,   k u b e a d m   r u n s   t h e   f o l l o w i n g   t w o   c o m m a n d s   t o   l o a d   t h e   n e w   c o n f i g u r a t i o n   i n t o   t h e   k u b e l e t :   s y s t e m c t l   d a e m o n - r e l o a d   & &   s y s t e m c t l   r e s t a r t   k u b e l e t   A f t e r   t h e   k u b e l e t   l o a d s   t h e   n e w   c o n f i g u r a t i o n ,   k u b e a d m   w r i t e s   t h e   / e t c / k u b e r n e t e s / b o o t s t r a p - k u b e l e t . c o n f   K u b e C o n f i g   f i l e ,   w h i c h   c o n t a i n s   a   C A   c e r t i f i c a t e   a n d   B o o t s t r a p   T o k e n .   T h e s e   a r e   u s e d   b y   t h e   k u b e l e t   t o   p e r f o r m   t h e   T L S   B o o t s t r a p   a n d   o b t a i n   a   u n i q u e   c r e d e n t i a l ,   w h i c h   i s   s t o r e d   i n   / e t c / k u b e r n e t e s / k u b e l e t . c o n f .   W h e n   t h e   / e t c / k u b e r n e t e s / k u b e l e t . c o n f   f i l e   i s   w r


Question: What is The kubelet drop-in file for systemd?

Answer: k u b e a d m   s h i p s   w i t h   c o n f i g u r a t i o n   f o r   h o w   s y s t e m d   s h o u l d   r u n   t h e   k u b e l e t .   N o t e   t h a t   t h e   k u b e a d m   C L I   c o m m a n d   n e v e r   t o u c h e s   t h i s   d r o p - i n   f i l e .   T h i s   c o n f i g u r a t i o n   f i l e   i n s t a l l e d   b y   t h e   k u b e a d m   p a c k a g e   i s   w r i t t e n   t o   / u s r / l i b / s y s t e m d / s y s t e m / k u b e l e t . s e r v i c e . d / 1 0 - k u b e a d m . c o n f   a n d   i s   u s e d   b y   s y s t e m d .   I t   a u g m e n t s   t h e   b a s i c   k u b e l e t . s e r v i c e .   I f   y o u   w a n t   t o   o v e r r i d e   t h a t   f u r t h e r ,   y o u   c a n   m a k e   a   d i r e c t o r y   / e t c / s y s t e m d / s y s t e m / k u b e l e t . s e r v i c e . d /   ( n o t   / u s r / l i b / s y s t e m d / s y s t e m / k u b e l e t . s e r v i c e . d / )   a n d   p u t   y o u r   o w n   c u s t o m i z a t i o n s   i n t o   a   f i l e   t h e r e .   F o r   e x a m p l e ,   y o u   m i g h t   a d d   a   n e w   l o c a l   f i l e   / e t c / s y s t e m d / s y s t e m / k u b e l e t . s e r v i c e . d / l o c a l - o v e r r i d e s . c o n f   t o   o v e r r i d e   t h e   u n i t   s e t t i n g s   c o n f i g u r e d   b y   k u b e a d m .   H e r e   i s   w h a t   y o u   a r e   l i k e l y   t o   f i n d   i n   / u s r / l i b / s y s t e m d / s y s t e m / k u b e l e t . s e r v i c e . d / 1 0 - k u b e a d m . c o n f :


Question: What is Note:?

Answer: [ S e r v i c e ]   E n v i r o n m e n t = " K U B E L E T _ K U B E C O N F I G _ A R G S = - - b o o t s t r a p - k u b e c o n f i g = / e t c / k u b e r n e t e s / b o o t s t r a p - k u b e l e t . c o n f   - - k u b e c o n f i g = / e t c / k u b e r n e t e s / k u b e l e t . c o n f "   E n v i r o n m e n t = " K U B E L E T _ C O N F I G _ A R G S = - - c o n f i g = / v a r / l i b / k u b e l e t / c o n f i g . y a m l "   #   T h i s   i s   a   f i l e   t h a t   " k u b e a d m   i n i t "   a n d   " k u b e a d m   j o i n "   g e n e r a t e   a t   r u n t i m e ,   p o p u l a t i n g   #   t h e   K U B E L E T _ K U B E A D M _ A R G S   v a r i a b l e   d y n a m i c a l l y   E n v i r o n m e n t F i l e = - / v a r / l i b / k u b e l e t / k u b e a d m - f l a g s . e n v   #   T h i s   i s   a   f i l e   t h a t   t h e   u s e r   c a n   u s e   f o r   o v e r r i d e s   o f   t h e   k u b e l e t   a r g s   a s   a   l a s t   r e s o r t .   P r e f e r a b l y ,   #   t h e   u s e r   s h o u l d   u s e   t h e   . N o d e R e g i s t r a t i o n . K u b e l e t E x t r a A r g s   o b j e c t   i n   t h e   c o n f i g u r a t i o n   f i l e s   i n s t e a d .   #   K U B E L E T _ E X T R A _ A R G S   s h o u l d   b e   s o u r c e d   f r o m   t h i s   f i l e .   E n v i r o n m e n t F i l e = - / e t c / d e f a u l t / k u b e l e t   E x e c S t a r t =   E x e c S t a r t = / u s r / b i n / k u b e l e t   $ K U B E L E T _ K U B E C O N F I G _ A R G S   $ K U B E L E T _ C O N F I G _ A R G S   $ K U B E L E T _ K U B E A D M _ A R G S   $ K U B E L E T _ E X T R A _ A R G S   T h i s   f i l e   s p e c i f i e s   t h e   d e f a u l t   l o c a t i o n s   f o r   a l l   o f   t h e   f i l e s   m a n a g e d   b y   k u b e a d m   f o r   t h e   k u b e l e t .   T h e   K u b e C o n f i g   f i l e   t o   u s e   f o r   t h e   T L S   B o o t s t r a p   i s   / e t c / k u b e r n


Question: What is Kubernetes binaries and package contents?

Answer: T h e   D E B   a n d   R P M   p a c k a g e s   s h i p p e d   w i t h   t h e   K u b e r n e t e s   r e l e a s e s   a r e :


Question: What is Content organization?

Answer: Content organizationThis site uses Hugo. In Hugo, content organization is a core concept.Note:Hugo Tip: Start Hugo with hugo server --navigateToChanged for content edit-sessions.Page ListsPage OrderThe documentation side menu, the documentation page browser etc. are listed using Hugo's default sort order, which sorts by weight (from 1), date (newest first), and finally by the link title.Given that, if you want to move a page or a section up, set a weight in the page's front matter:title: My Page weight: 10 Note:For page weights, it can be smart not to use 1, 2, 3 ..., but some other interval, say 10, 20, 30... This allows you to insert pages where you want later. Additionally, each weight within the same directory (section) should not be overlapped with the other weights. This makes sure that content is always organized correctly, especially in localized content.Documentation Main MenuThe Documentation main menu is built from the sections below docs/ with the main_menu flag set in front matter of the _index.md section content file:main_menu: true Note that the link title is fetched from the page's linkTitle, so if you want it to be something different than the title, change it in the content file:main_menu: true title: Page Title linkTitle: Title used in links Note:The above needs to be done per language. If you don't see your section in the menu, it is probably because it is not identified as a section by Hugo. Create a _index.md content file in the section folder.Documentation Side MenuThe documentation side-bar menu is built from the current section tree starting below docs/.It will show all sections and their pages.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true When you navigate to a section that has content, the specific section or page (e.g. _index.md) is shown. Else, the first page inside that section is shown.Documentation BrowserThe page browser on the documentation home page is built using all the sections and pages that are directly below the docs section.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true The Main MenuThe site links in the top-right menu -- and also in the footer -- are built by page-lookups. This is to make sure that the page actually exists. So, if the case-studies section does not exist in a site (language), it will not be linked to.Page BundlesIn addition to standalone content pages (Markdown files), Hugo supports Page Bundles.One example is Custom Hugo Shortcodes. It is considered a leaf bundle. Everything below the directory, including the index.md, will be part of the bundle. This also includes page-relative links, images that can be processed etc.:en/docs/home/contribute/includes ├── example1.md ├── example2.md ├── index.md └── podtemplate.json Another widely used example is the includes bundle. It sets headless: true in front matter, which means that it does not get its own URL. It is only used in


Question: How does Content organization work?

Answer: Content organizationThis site uses Hugo. In Hugo, content organization is a core concept.Note:Hugo Tip: Start Hugo with hugo server --navigateToChanged for content edit-sessions.Page ListsPage OrderThe documentation side menu, the documentation page browser etc. are listed using Hugo's default sort order, which sorts by weight (from 1), date (newest first), and finally by the link title.Given that, if you want to move a page or a section up, set a weight in the page's front matter:title: My Page weight: 10 Note:For page weights, it can be smart not to use 1, 2, 3 ..., but some other interval, say 10, 20, 30... This allows you to insert pages where you want later. Additionally, each weight within the same directory (section) should not be overlapped with the other weights. This makes sure that content is always organized correctly, especially in localized content.Documentation Main MenuThe Documentation main menu is built from the sections below docs/ with the main_menu flag set in front matter of the _index.md section content file:main_menu: true Note that the link title is fetched from the page's linkTitle, so if you want it to be something different than the title, change it in the content file:main_menu: true title: Page Title linkTitle: Title used in links Note:The above needs to be done per language. If you don't see your section in the menu, it is probably because it is not identified as a section by Hugo. Create a _index.md content file in the section folder.Documentation Side MenuThe documentation side-bar menu is built from the current section tree starting below docs/.It will show all sections and their pages.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true When you navigate to a section that has content, the specific section or page (e.g. _index.md) is shown. Else, the first page inside that section is shown.Documentation BrowserThe page browser on the documentation home page is built using all the sections and pages that are directly below the docs section.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true The Main MenuThe site links in the top-right menu -- and also in the footer -- are built by page-lookups. This is to make sure that the page actually exists. So, if the case-studies section does not exist in a site (language), it will not be linked to.Page BundlesIn addition to standalone content pages (Markdown files), Hugo supports Page Bundles.One example is Custom Hugo Shortcodes. It is considered a leaf bundle. Everything below the directory, including the index.md, will be part of the bundle. This also includes page-relative links, images that can be processed etc.:en/docs/home/contribute/includes ├── example1.md ├── example2.md ├── index.md └── podtemplate.json Another widely used example is the includes bundle. It sets headless: true in front matter, which means that it does not get its own URL. It is only used in


Question: When would you use Content organization?

Answer: Content organizationThis site uses Hugo. In Hugo, content organization is a core concept.Note:Hugo Tip: Start Hugo with hugo server --navigateToChanged for content edit-sessions.Page ListsPage OrderThe documentation side menu, the documentation page browser etc. are listed using Hugo's default sort order, which sorts by weight (from 1), date (newest first), and finally by the link title.Given that, if you want to move a page or a section up, set a weight in the page's front matter:title: My Page weight: 10 Note:For page weights, it can be smart not to use 1, 2, 3 ..., but some other interval, say 10, 20, 30... This allows you to insert pages where you want later. Additionally, each weight within the same directory (section) should not be overlapped with the other weights. This makes sure that content is always organized correctly, especially in localized content.Documentation Main MenuThe Documentation main menu is built from the sections below docs/ with the main_menu flag set in front matter of the _index.md section content file:main_menu: true Note that the link title is fetched from the page's linkTitle, so if you want it to be something different than the title, change it in the content file:main_menu: true title: Page Title linkTitle: Title used in links Note:The above needs to be done per language. If you don't see your section in the menu, it is probably because it is not identified as a section by Hugo. Create a _index.md content file in the section folder.Documentation Side MenuThe documentation side-bar menu is built from the current section tree starting below docs/.It will show all sections and their pages.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true When you navigate to a section that has content, the specific section or page (e.g. _index.md) is shown. Else, the first page inside that section is shown.Documentation BrowserThe page browser on the documentation home page is built using all the sections and pages that are directly below the docs section.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true The Main MenuThe site links in the top-right menu -- and also in the footer -- are built by page-lookups. This is to make sure that the page actually exists. So, if the case-studies section does not exist in a site (language), it will not be linked to.Page BundlesIn addition to standalone content pages (Markdown files), Hugo supports Page Bundles.One example is Custom Hugo Shortcodes. It is considered a leaf bundle. Everything below the directory, including the index.md, will be part of the bundle. This also includes page-relative links, images that can be processed etc.:en/docs/home/contribute/includes ├── example1.md ├── example2.md ├── index.md └── podtemplate.json Another widely used example is the includes bundle. It sets headless: true in front matter, which means that it does not get its own URL. It is only used in


Question: What are the benefits of Content organization?

Answer: Content organizationThis site uses Hugo. In Hugo, content organization is a core concept.Note:Hugo Tip: Start Hugo with hugo server --navigateToChanged for content edit-sessions.Page ListsPage OrderThe documentation side menu, the documentation page browser etc. are listed using Hugo's default sort order, which sorts by weight (from 1), date (newest first), and finally by the link title.Given that, if you want to move a page or a section up, set a weight in the page's front matter:title: My Page weight: 10 Note:For page weights, it can be smart not to use 1, 2, 3 ..., but some other interval, say 10, 20, 30... This allows you to insert pages where you want later. Additionally, each weight within the same directory (section) should not be overlapped with the other weights. This makes sure that content is always organized correctly, especially in localized content.Documentation Main MenuThe Documentation main menu is built from the sections below docs/ with the main_menu flag set in front matter of the _index.md section content file:main_menu: true Note that the link title is fetched from the page's linkTitle, so if you want it to be something different than the title, change it in the content file:main_menu: true title: Page Title linkTitle: Title used in links Note:The above needs to be done per language. If you don't see your section in the menu, it is probably because it is not identified as a section by Hugo. Create a _index.md content file in the section folder.Documentation Side MenuThe documentation side-bar menu is built from the current section tree starting below docs/.It will show all sections and their pages.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true When you navigate to a section that has content, the specific section or page (e.g. _index.md) is shown. Else, the first page inside that section is shown.Documentation BrowserThe page browser on the documentation home page is built using all the sections and pages that are directly below the docs section.If you don't want to list a section or page, set the toc_hide flag to true in front matter:toc_hide: true The Main MenuThe site links in the top-right menu -- and also in the footer -- are built by page-lookups. This is to make sure that the page actually exists. So, if the case-studies section does not exist in a site (language), it will not be linked to.Page BundlesIn addition to standalone content pages (Markdown files), Hugo supports Page Bundles.One example is Custom Hugo Shortcodes. It is considered a leaf bundle. Everything below the directory, including the index.md, will be part of the bundle. This also includes page-relative links, images that can be processed etc.:en/docs/home/contribute/includes ├── example1.md ├── example2.md ├── index.md └── podtemplate.json Another widely used example is the includes bundle. It sets headless: true in front matter, which means that it does not get its own URL. It is only used in


Question: What is Content organization?

Answer: T h i s   s i t e   u s e s   H u g o .   I n   H u g o ,   c o n t e n t   o r g a n i z a t i o n   i s   a   c o r e   c o n c e p t .


Question: What is Page Order?

Answer: T h e   d o c u m e n t a t i o n   s i d e   m e n u ,   t h e   d o c u m e n t a t i o n   p a g e   b r o w s e r   e t c .   a r e   l i s t e d   u s i n g   H u g o ' s   d e f a u l t   s o r t   o r d e r ,   w h i c h   s o r t s   b y   w e i g h t   ( f r o m   1 ) ,   d a t e   ( n e w e s t   f i r s t ) ,   a n d   f i n a l l y   b y   t h e   l i n k   t i t l e .   G i v e n   t h a t ,   i f   y o u   w a n t   t o   m o v e   a   p a g e   o r   a   s e c t i o n   u p ,   s e t   a   w e i g h t   i n   t h e   p a g e ' s   f r o n t   m a t t e r :   t i t l e :   M y   P a g e   w e i g h t :   1 0


Question: What is Documentation Main Menu?

Answer: T h e   D o c u m e n t a t i o n   m a i n   m e n u   i s   b u i l t   f r o m   t h e   s e c t i o n s   b e l o w   d o c s /   w i t h   t h e   m a i n _ m e n u   f l a g   s e t   i n   f r o n t   m a t t e r   o f   t h e   _ i n d e x . m d   s e c t i o n   c o n t e n t   f i l e :   m a i n _ m e n u :   t r u e   N o t e   t h a t   t h e   l i n k   t i t l e   i s   f e t c h e d   f r o m   t h e   p a g e ' s   l i n k T i t l e ,   s o   i f   y o u   w a n t   i t   t o   b e   s o m e t h i n g   d i f f e r e n t   t h a n   t h e   t i t l e ,   c h a n g e   i t   i n   t h e   c o n t e n t   f i l e :   m a i n _ m e n u :   t r u e   t i t l e :   P a g e   T i t l e   l i n k T i t l e :   T i t l e   u s e d   i n   l i n k s


Question: What is Documentation Side Menu?

Answer: T h e   d o c u m e n t a t i o n   s i d e - b a r   m e n u   i s   b u i l t   f r o m   t h e   c u r r e n t   s e c t i o n   t r e e   s t a r t i n g   b e l o w   d o c s / .   I t   w i l l   s h o w   a l l   s e c t i o n s   a n d   t h e i r   p a g e s .   I f   y o u   d o n ' t   w a n t   t o   l i s t   a   s e c t i o n   o r   p a g e ,   s e t   t h e   t o c _ h i d e   f l a g   t o   t r u e   i n   f r o n t   m a t t e r :   t o c _ h i d e :   t r u e   W h e n   y o u   n a v i g a t e   t o   a   s e c t i o n   t h a t   h a s   c o n t e n t ,   t h e   s p e c i f i c   s e c t i o n   o r   p a g e   ( e . g .   _ i n d e x . m d )   i s   s h o w n .   E l s e ,   t h e   f i r s t   p a g e   i n s i d e   t h a t   s e c t i o n   i s   s h o w n .


Question: What is Documentation Browser?

Answer: T h e   p a g e   b r o w s e r   o n   t h e   d o c u m e n t a t i o n   h o m e   p a g e   i s   b u i l t   u s i n g   a l l   t h e   s e c t i o n s   a n d   p a g e s   t h a t   a r e   d i r e c t l y   b e l o w   t h e   d o c s   s e c t i o n .   I f   y o u   d o n ' t   w a n t   t o   l i s t   a   s e c t i o n   o r   p a g e ,   s e t   t h e   t o c _ h i d e   f l a g   t o   t r u e   i n   f r o n t   m a t t e r :   t o c _ h i d e :   t r u e


Question: What is The Main Menu?

Answer: T h e   s i t e   l i n k s   i n   t h e   t o p - r i g h t   m e n u   - -   a n d   a l s o   i n   t h e   f o o t e r   - -   a r e   b u i l t   b y   p a g e - l o o k u p s .   T h i s   i s   t o   m a k e   s u r e   t h a t   t h e   p a g e   a c t u a l l y   e x i s t s .   S o ,   i f   t h e   c a s e - s t u d i e s   s e c t i o n   d o e s   n o t   e x i s t   i n   a   s i t e   ( l a n g u a g e ) ,   i t   w i l l   n o t   b e   l i n k e d   t o .


Question: What is Page Bundles?

Answer: I n   a d d i t i o n   t o   s t a n d a l o n e   c o n t e n t   p a g e s   ( M a r k d o w n   f i l e s ) ,   H u g o   s u p p o r t s   P a g e   B u n d l e s .   O n e   e x a m p l e   i s   C u s t o m   H u g o   S h o r t c o d e s .   I t   i s   c o n s i d e r e d   a   l e a f   b u n d l e .   E v e r y t h i n g   b e l o w   t h e   d i r e c t o r y ,   i n c l u d i n g   t h e   i n d e x . m d ,   w i l l   b e   p a r t   o f   t h e   b u n d l e .   T h i s   a l s o   i n c l u d e s   p a g e - r e l a t i v e   l i n k s ,   i m a g e s   t h a t   c a n   b e   p r o c e s s e d   e t c . :   e n / d o c s / h o m e / c o n t r i b u t e / i n c l u d e s   ├ ─ ─   e x a m p l e 1 . m d   ├ ─ ─   e x a m p l e 2 . m d   ├ ─ ─   i n d e x . m d   └ ─ ─   p o d t e m p l a t e . j s o n   A n o t h e r   w i d e l y   u s e d   e x a m p l e   i s   t h e   i n c l u d e s   b u n d l e .   I t   s e t s   h e a d l e s s :   t r u e   i n   f r o n t   m a t t e r ,   w h i c h   m e a n s   t h a t   i t   d o e s   n o t   g e t   i t s   o w n   U R L .   I t   i s   o n l y   u s e d   i n   o t h e r   p a g e s .   e n / i n c l u d e s   ├ ─ ─   d e f a u l t - s t o r a g e - c l a s s - p r e r e q s . m d   ├ ─ ─   i n d e x . m d   ├ ─ ─   p a r t n e r - s c r i p t . j s   ├ ─ ─   p a r t n e r - s t y l e . c s s   ├ ─ ─   t a s k - t u t o r i a l - p r e r e q s . m d   ├ ─ ─   u s e r - g u i d e - c o n t e n t - m o v e d . m d   └ ─ ─   u s e r - g u i d e - m i g r a t i o n - n o t i c e . m d   S o m e   i m p o r t a n t   n o t e s   t o   t h e   f i l e s   i n   t h e   b u n d l e s :   F o r   t r a n s l a t e d   b u n d l e s ,   a n y   m i s s i n g   n o n - c o n t e n t   f i l e s   w i l l   b e   i n h e r i t e d   f r o m   l a n g u a g e s   a b o v e .   T h i s   a v o i d s   d u p l i c a t i o n . A l l   t h e   f i l e s   i n   a   b u n d l e   a r e   w h a t   H u g o   c a l l s


Question: What is Styles?

Answer: T h e   S A S S   s o u r c e   o f   t h e   s t y l e s h e e t s   f o r   t h i s   s i t e   i s   s t o r e d   i n   a s s e t s / s a s s   a n d   i s   a u t o m a t i c a l l y   b u i l t   b y   H u g o .


Question: What is What's next?

Answer: L e a r n   a b o u t   c u s t o m   H u g o   s h o r t c o d e s L e a r n   a b o u t   t h e   S t y l e   g u i d e L e a r n   a b o u t   t h e   C o n t e n t   g u i d e


Question: What is Concepts?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Concepts1: Overview1.1: Kubernetes Components1.2: Objects In Kubernetes1.2.1: Kubernetes Object Management1.2.2: Object Names and IDs1.2.3: Labels and Selectors1.2.4: Namespaces1.2.5: Annotations1.2.6: Field Selectors1.2.7: Finalizers1.2.8: Owners and Dependents1.2.9: Recommended Labels1.3: The Kubernetes API2: Cluster Architecture2.1: Nodes2.2: Communication between Nodes and the Control Plane2.3: Controllers2.4: Leases2.5: Cloud Controller Manager2.6: About cgroup v22.7: Kubernetes Self-Healing2.8: Container Runtime Interface (CRI)2.9: Garbage Collection2.10: Mixed Version Proxy3: Containers3.1: Images3.2: Container Environment3.3: Runtime Class3.4: Container Lifecycle Hooks4: Workloads4.1: Pods4.1.1: Pod Lifecycle4.1.2: Init Containers4.1.3: Sidecar Containers4.1.4: Ephemeral Containers4.1.5: Disruptions4.1.6: Pod Hostname4.1.7: Pod Quality of Service Classes4.1.8: User Namespaces4.1.9: Downward API4.2: Workload Management4.2.1: Deployments4.2.2: ReplicaSet4.2.3: StatefulSets4.2.4: DaemonSet4.2.5: Jobs4.2.6: Automatic Cleanup for Finished Jobs4.2.7: CronJob4.2.8: ReplicationController4.3: Autoscaling Workloads4.4: Managing Workloads5: Services, Load Balancing, and Networking5.1: Service5.2: Ingress5.3: Ingress Controllers5.4: Gateway API5.5: EndpointSlices5.6: Network Policies5.7: DNS for Services and Pods5.8: IPv4/IPv6 dual-stack5.9: Topology Aware Routing5.10: Networking on Windows5.11: Service ClusterIP allocation5.12: Service Internal Traffic Policy6: Storage6.1: Volumes6.2: Persistent Volumes6.3: Projected Volumes6.4: Ephemeral Volumes6.5: Storage Classes6.6: Volume Attributes Classes6.7: Dynamic Volume Provisioning6.8: Volume Snapshots6.9: Volume Snapshot Classes6.10: CSI Volume Cloning6.11: Storage Capacity6.12: Node-specific Volume Limits6.13: Volume Health Monitoring6.14: Windows Storage7: Configuration7.1: Configuration Best Practices7.2: ConfigMaps7.3: Secrets7.4: Liveness, Readiness, and Startup Probes7.5: Resource Management for Pods and Containers7.6: Organizing Cluster Access Using kubeconfig Files7.7: Resource Management for Windows nodes8: Security8.1: Cloud Native Security and Kubernetes8.2: Pod Security Standards8.3: Pod Security Admission8.4: Service Accounts8.5: Pod Security Policies8.6: Security For Linux Nodes8.7: Security For Windows Nodes8.8: Controlling Access to the Kubernetes API8.9: Role Based Access Control Good Practices8.10: Good practices for Kubernetes Secrets8.11: Multi-tenancy8.12: Hardening Guide - Authentication Mechanisms8.13: Hardening Guide - Scheduler Configuration8.14: Kubernetes API Server Bypass Risks8.15: Linux kernel security constraints for Pods and containers8.16: Security Checklist8.17: Application Security Checklist9: Policies9.1: Limit Ranges9.2: Resource Quotas9.3: Process ID Limits And Reservations9.4: Node Resource Managers10: Scheduling, Preemption and Eviction10.1: Kubernete


Question: How does Concepts work?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Concepts1: Overview1.1: Kubernetes Components1.2: Objects In Kubernetes1.2.1: Kubernetes Object Management1.2.2: Object Names and IDs1.2.3: Labels and Selectors1.2.4: Namespaces1.2.5: Annotations1.2.6: Field Selectors1.2.7: Finalizers1.2.8: Owners and Dependents1.2.9: Recommended Labels1.3: The Kubernetes API2: Cluster Architecture2.1: Nodes2.2: Communication between Nodes and the Control Plane2.3: Controllers2.4: Leases2.5: Cloud Controller Manager2.6: About cgroup v22.7: Kubernetes Self-Healing2.8: Container Runtime Interface (CRI)2.9: Garbage Collection2.10: Mixed Version Proxy3: Containers3.1: Images3.2: Container Environment3.3: Runtime Class3.4: Container Lifecycle Hooks4: Workloads4.1: Pods4.1.1: Pod Lifecycle4.1.2: Init Containers4.1.3: Sidecar Containers4.1.4: Ephemeral Containers4.1.5: Disruptions4.1.6: Pod Hostname4.1.7: Pod Quality of Service Classes4.1.8: User Namespaces4.1.9: Downward API4.2: Workload Management4.2.1: Deployments4.2.2: ReplicaSet4.2.3: StatefulSets4.2.4: DaemonSet4.2.5: Jobs4.2.6: Automatic Cleanup for Finished Jobs4.2.7: CronJob4.2.8: ReplicationController4.3: Autoscaling Workloads4.4: Managing Workloads5: Services, Load Balancing, and Networking5.1: Service5.2: Ingress5.3: Ingress Controllers5.4: Gateway API5.5: EndpointSlices5.6: Network Policies5.7: DNS for Services and Pods5.8: IPv4/IPv6 dual-stack5.9: Topology Aware Routing5.10: Networking on Windows5.11: Service ClusterIP allocation5.12: Service Internal Traffic Policy6: Storage6.1: Volumes6.2: Persistent Volumes6.3: Projected Volumes6.4: Ephemeral Volumes6.5: Storage Classes6.6: Volume Attributes Classes6.7: Dynamic Volume Provisioning6.8: Volume Snapshots6.9: Volume Snapshot Classes6.10: CSI Volume Cloning6.11: Storage Capacity6.12: Node-specific Volume Limits6.13: Volume Health Monitoring6.14: Windows Storage7: Configuration7.1: Configuration Best Practices7.2: ConfigMaps7.3: Secrets7.4: Liveness, Readiness, and Startup Probes7.5: Resource Management for Pods and Containers7.6: Organizing Cluster Access Using kubeconfig Files7.7: Resource Management for Windows nodes8: Security8.1: Cloud Native Security and Kubernetes8.2: Pod Security Standards8.3: Pod Security Admission8.4: Service Accounts8.5: Pod Security Policies8.6: Security For Linux Nodes8.7: Security For Windows Nodes8.8: Controlling Access to the Kubernetes API8.9: Role Based Access Control Good Practices8.10: Good practices for Kubernetes Secrets8.11: Multi-tenancy8.12: Hardening Guide - Authentication Mechanisms8.13: Hardening Guide - Scheduler Configuration8.14: Kubernetes API Server Bypass Risks8.15: Linux kernel security constraints for Pods and containers8.16: Security Checklist8.17: Application Security Checklist9: Policies9.1: Limit Ranges9.2: Resource Quotas9.3: Process ID Limits And Reservations9.4: Node Resource Managers10: Scheduling, Preemption and Eviction10.1: Kubernete


Question: When would you use Concepts?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Concepts1: Overview1.1: Kubernetes Components1.2: Objects In Kubernetes1.2.1: Kubernetes Object Management1.2.2: Object Names and IDs1.2.3: Labels and Selectors1.2.4: Namespaces1.2.5: Annotations1.2.6: Field Selectors1.2.7: Finalizers1.2.8: Owners and Dependents1.2.9: Recommended Labels1.3: The Kubernetes API2: Cluster Architecture2.1: Nodes2.2: Communication between Nodes and the Control Plane2.3: Controllers2.4: Leases2.5: Cloud Controller Manager2.6: About cgroup v22.7: Kubernetes Self-Healing2.8: Container Runtime Interface (CRI)2.9: Garbage Collection2.10: Mixed Version Proxy3: Containers3.1: Images3.2: Container Environment3.3: Runtime Class3.4: Container Lifecycle Hooks4: Workloads4.1: Pods4.1.1: Pod Lifecycle4.1.2: Init Containers4.1.3: Sidecar Containers4.1.4: Ephemeral Containers4.1.5: Disruptions4.1.6: Pod Hostname4.1.7: Pod Quality of Service Classes4.1.8: User Namespaces4.1.9: Downward API4.2: Workload Management4.2.1: Deployments4.2.2: ReplicaSet4.2.3: StatefulSets4.2.4: DaemonSet4.2.5: Jobs4.2.6: Automatic Cleanup for Finished Jobs4.2.7: CronJob4.2.8: ReplicationController4.3: Autoscaling Workloads4.4: Managing Workloads5: Services, Load Balancing, and Networking5.1: Service5.2: Ingress5.3: Ingress Controllers5.4: Gateway API5.5: EndpointSlices5.6: Network Policies5.7: DNS for Services and Pods5.8: IPv4/IPv6 dual-stack5.9: Topology Aware Routing5.10: Networking on Windows5.11: Service ClusterIP allocation5.12: Service Internal Traffic Policy6: Storage6.1: Volumes6.2: Persistent Volumes6.3: Projected Volumes6.4: Ephemeral Volumes6.5: Storage Classes6.6: Volume Attributes Classes6.7: Dynamic Volume Provisioning6.8: Volume Snapshots6.9: Volume Snapshot Classes6.10: CSI Volume Cloning6.11: Storage Capacity6.12: Node-specific Volume Limits6.13: Volume Health Monitoring6.14: Windows Storage7: Configuration7.1: Configuration Best Practices7.2: ConfigMaps7.3: Secrets7.4: Liveness, Readiness, and Startup Probes7.5: Resource Management for Pods and Containers7.6: Organizing Cluster Access Using kubeconfig Files7.7: Resource Management for Windows nodes8: Security8.1: Cloud Native Security and Kubernetes8.2: Pod Security Standards8.3: Pod Security Admission8.4: Service Accounts8.5: Pod Security Policies8.6: Security For Linux Nodes8.7: Security For Windows Nodes8.8: Controlling Access to the Kubernetes API8.9: Role Based Access Control Good Practices8.10: Good practices for Kubernetes Secrets8.11: Multi-tenancy8.12: Hardening Guide - Authentication Mechanisms8.13: Hardening Guide - Scheduler Configuration8.14: Kubernetes API Server Bypass Risks8.15: Linux kernel security constraints for Pods and containers8.16: Security Checklist8.17: Application Security Checklist9: Policies9.1: Limit Ranges9.2: Resource Quotas9.3: Process ID Limits And Reservations9.4: Node Resource Managers10: Scheduling, Preemption and Eviction10.1: Kubernete


Question: What are the benefits of Concepts?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Concepts1: Overview1.1: Kubernetes Components1.2: Objects In Kubernetes1.2.1: Kubernetes Object Management1.2.2: Object Names and IDs1.2.3: Labels and Selectors1.2.4: Namespaces1.2.5: Annotations1.2.6: Field Selectors1.2.7: Finalizers1.2.8: Owners and Dependents1.2.9: Recommended Labels1.3: The Kubernetes API2: Cluster Architecture2.1: Nodes2.2: Communication between Nodes and the Control Plane2.3: Controllers2.4: Leases2.5: Cloud Controller Manager2.6: About cgroup v22.7: Kubernetes Self-Healing2.8: Container Runtime Interface (CRI)2.9: Garbage Collection2.10: Mixed Version Proxy3: Containers3.1: Images3.2: Container Environment3.3: Runtime Class3.4: Container Lifecycle Hooks4: Workloads4.1: Pods4.1.1: Pod Lifecycle4.1.2: Init Containers4.1.3: Sidecar Containers4.1.4: Ephemeral Containers4.1.5: Disruptions4.1.6: Pod Hostname4.1.7: Pod Quality of Service Classes4.1.8: User Namespaces4.1.9: Downward API4.2: Workload Management4.2.1: Deployments4.2.2: ReplicaSet4.2.3: StatefulSets4.2.4: DaemonSet4.2.5: Jobs4.2.6: Automatic Cleanup for Finished Jobs4.2.7: CronJob4.2.8: ReplicationController4.3: Autoscaling Workloads4.4: Managing Workloads5: Services, Load Balancing, and Networking5.1: Service5.2: Ingress5.3: Ingress Controllers5.4: Gateway API5.5: EndpointSlices5.6: Network Policies5.7: DNS for Services and Pods5.8: IPv4/IPv6 dual-stack5.9: Topology Aware Routing5.10: Networking on Windows5.11: Service ClusterIP allocation5.12: Service Internal Traffic Policy6: Storage6.1: Volumes6.2: Persistent Volumes6.3: Projected Volumes6.4: Ephemeral Volumes6.5: Storage Classes6.6: Volume Attributes Classes6.7: Dynamic Volume Provisioning6.8: Volume Snapshots6.9: Volume Snapshot Classes6.10: CSI Volume Cloning6.11: Storage Capacity6.12: Node-specific Volume Limits6.13: Volume Health Monitoring6.14: Windows Storage7: Configuration7.1: Configuration Best Practices7.2: ConfigMaps7.3: Secrets7.4: Liveness, Readiness, and Startup Probes7.5: Resource Management for Pods and Containers7.6: Organizing Cluster Access Using kubeconfig Files7.7: Resource Management for Windows nodes8: Security8.1: Cloud Native Security and Kubernetes8.2: Pod Security Standards8.3: Pod Security Admission8.4: Service Accounts8.5: Pod Security Policies8.6: Security For Linux Nodes8.7: Security For Windows Nodes8.8: Controlling Access to the Kubernetes API8.9: Role Based Access Control Good Practices8.10: Good practices for Kubernetes Secrets8.11: Multi-tenancy8.12: Hardening Guide - Authentication Mechanisms8.13: Hardening Guide - Scheduler Configuration8.14: Kubernetes API Server Bypass Risks8.15: Linux kernel security constraints for Pods and containers8.16: Security Checklist8.17: Application Security Checklist9: Policies9.1: Limit Ranges9.2: Resource Quotas9.3: Process ID Limits And Reservations9.4: Node Resource Managers10: Scheduling, Preemption and Eviction10.1: Kubernete


Question: What is Concepts?

Answer: 1 :   O v e r v i e w 1 . 1 :   K u b e r n e t e s   C o m p o n e n t s 1 . 2 :   O b j e c t s   I n   K u b e r n e t e s 1 . 2 . 1 :   K u b e r n e t e s   O b j e c t   M a n a g e m e n t 1 . 2 . 2 :   O b j e c t   N a m e s   a n d   I D s 1 . 2 . 3 :   L a b e l s   a n d   S e l e c t o r s 1 . 2 . 4 :   N a m e s p a c e s 1 . 2 . 5 :   A n n o t a t i o n s 1 . 2 . 6 :   F i e l d   S e l e c t o r s 1 . 2 . 7 :   F i n a l i z e r s 1 . 2 . 8 :   O w n e r s   a n d   D e p e n d e n t s 1 . 2 . 9 :   R e c o m m e n d e d   L a b e l s 1 . 3 :   T h e   K u b e r n e t e s   A P I 2 :   C l u s t e r   A r c h i t e c t u r e 2 . 1 :   N o d e s 2 . 2 :   C o m m u n i c a t i o n   b e t w e e n   N o d e s   a n d   t h e   C o n t r o l   P l a n e 2 . 3 :   C o n t r o l l e r s 2 . 4 :   L e a s e s 2 . 5 :   C l o u d   C o n t r o l l e r   M a n a g e r 2 . 6 :   A b o u t   c g r o u p   v 2 2 . 7 :   K u b e r n e t e s   S e l f - H e a l i n g 2 . 8 :   C o n t a i n e r   R u n t i m e   I n t e r f a c e   ( C R I ) 2 . 9 :   G a r b a g e   C o l l e c t i o n 2 . 1 0 :   M i x e d   V e r s i o n   P r o x y 3 :   C o n t a i n e r s 3 . 1 :   I m a g e s 3 . 2 :   C o n t a i n e r   E n v i r o n m e n t 3 . 3 :   R u n t i m e   C l a s s 3 . 4 :   C o n t a i n e r   L i f e c y c l e   H o o k s 4 :   W o r k l o a d s 4 . 1 :   P o d s 4 . 1 . 1 :   P o d   L i f e c y c l e 4 . 1 . 2 :   I n i t   C o n t a i n e r s 4 . 1 . 3 :   S i d e c a r   C o n t a i n e r s 4 . 1 . 4 :   E p h e m e r a l   C o n t a i n e r s 4 . 1 . 5 :   D i s r u p t i o n s 4 . 1 . 6 :   P o d   H o s t n a m e 4 . 1 . 7 :   P o d   Q u a l i t y   o f   S e r v i c e   C l a s s e s 4 . 1 . 8 :   U s e r   N a m e s p a c e s 4 . 1 . 9 :   D o w n w a r d   A P I 4 . 2 :   W o r k l o a d   M a n a g e m e n t 4 . 2 . 1 :   D e p l o y m e n t s 4 . 2 . 2 :   R e p l i c a S e t 4 . 2 . 3 :   S t a t e f u l S e t s 4 . 2 . 4 :   D a e m o n S e


Question: What is 1 - Overview?

Answer: T h i s   p a g e   i s   a n   o v e r v i e w   o f   K u b e r n e t e s .   T h e   n a m e   K u b e r n e t e s   o r i g i n a t e s   f r o m   G r e e k ,   m e a n i n g   h e l m s m a n   o r   p i l o t .   K 8 s   a s   a n   a b b r e v i a t i o n   r e s u l t s   f r o m   c o u n t i n g   t h e   e i g h t   l e t t e r s   b e t w e e n   t h e   " K "   a n d   t h e   " s " .   G o o g l e   o p e n - s o u r c e d   t h e   K u b e r n e t e s   p r o j e c t   i n   2 0 1 4 .   K u b e r n e t e s   c o m b i n e s   o v e r   1 5   y e a r s   o f   G o o g l e ' s   e x p e r i e n c e   r u n n i n g   p r o d u c t i o n   w o r k l o a d s   a t   s c a l e   w i t h   b e s t - o f - b r e e d   i d e a s   a n d   p r a c t i c e s   f r o m   t h e   c o m m u n i t y .


Question: What is Why you need Kubernetes and what it can do?

Answer: C o n t a i n e r s   a r e   a   g o o d   w a y   t o   b u n d l e   a n d   r u n   y o u r   a p p l i c a t i o n s .   I n   a   p r o d u c t i o n   e n v i r o n m e n t ,   y o u   n e e d   t o   m a n a g e   t h e   c o n t a i n e r s   t h a t   r u n   t h e   a p p l i c a t i o n s   a n d   e n s u r e   t h a t   t h e r e   i s   n o   d o w n t i m e .   F o r   e x a m p l e ,   i f   a   c o n t a i n e r   g o e s   d o w n ,   a n o t h e r   c o n t a i n e r   n e e d s   t o   s t a r t .   W o u l d n ' t   i t   b e   e a s i e r   i f   t h i s   b e h a v i o r   w a s   h a n d l e d   b y   a   s y s t e m ?   T h a t ' s   h o w   K u b e r n e t e s   c o m e s   t o   t h e   r e s c u e !   K u b e r n e t e s   p r o v i d e s   y o u   w i t h   a   f r a m e w o r k   t o   r u n   d i s t r i b u t e d   s y s t e m s   r e s i l i e n t l y .   I t   t a k e s   c a r e   o f   s c a l i n g   a n d   f a i l o v e r   f o r   y o u r   a p p l i c a t i o n ,   p r o v i d e s   d e p l o y m e n t   p a t t e r n s ,   a n d   m o r e .   F o r   e x a m p l e :   K u b e r n e t e s   c a n   e a s i l y   m a n a g e   a   c a n a r y   d e p l o y m e n t   f o r   y o u r   s y s t e m .   K u b e r n e t e s   p r o v i d e s   y o u   w i t h :   S e r v i c e   d i s c o v e r y   a n d   l o a d   b a l a n c i n g   K u b e r n e t e s   c a n   e x p o s e   a   c o n t a i n e r   u s i n g   t h e   D N S   n a m e   o r   u s i n g   t h e i r   o w n   I P   a d d r e s s .   I f   t r a f f i c   t o   a   c o n t a i n e r   i s   h i g h ,   K u b e r n e t e s   i s   a b l e   t o   l o a d   b a l a n c e   a n d   d i s t r i b u t e   t h e   n e t w o r k   t r a f f i c   s o   t h a t   t h e   d e p l o y m e n t   i s   s t a b l e . S t o r a g e   o r c h e s t r a t i o n   K u b e r n e t e s   a l l o w s   y o u   t o   a u t o m a t i c a l l y   m o u n t   a   s t o r a g e   s y s t


Question: What is What Kubernetes is not?

Answer: K u b e r n e t e s   i s   n o t   a   t r a d i t i o n a l ,   a l l - i n c l u s i v e   P a a S   ( P l a t f o r m   a s   a   S e r v i c e )   s y s t e m .   S i n c e   K u b e r n e t e s   o p e r a t e s   a t   t h e   c o n t a i n e r   l e v e l   r a t h e r   t h a n   a t   t h e   h a r d w a r e   l e v e l ,   i t   p r o v i d e s   s o m e   g e n e r a l l y   a p p l i c a b l e   f e a t u r e s   c o m m o n   t o   P a a S   o f f e r i n g s ,   s u c h   a s   d e p l o y m e n t ,   s c a l i n g ,   l o a d   b a l a n c i n g ,   a n d   l e t s   u s e r s   i n t e g r a t e   t h e i r   l o g g i n g ,   m o n i t o r i n g ,   a n d   a l e r t i n g   s o l u t i o n s .   H o w e v e r ,   K u b e r n e t e s   i s   n o t   m o n o l i t h i c ,   a n d   t h e s e   d e f a u l t   s o l u t i o n s   a r e   o p t i o n a l   a n d   p l u g g a b l e .   K u b e r n e t e s   p r o v i d e s   t h e   b u i l d i n g   b l o c k s   f o r   b u i l d i n g   d e v e l o p e r   p l a t f o r m s ,   b u t   p r e s e r v e s   u s e r   c h o i c e   a n d   f l e x i b i l i t y   w h e r e   i t   i s   i m p o r t a n t .   K u b e r n e t e s :   D o e s   n o t   l i m i t   t h e   t y p e s   o f   a p p l i c a t i o n s   s u p p o r t e d .   K u b e r n e t e s   a i m s   t o   s u p p o r t   a n   e x t r e m e l y   d i v e r s e   v a r i e t y   o f   w o r k l o a d s ,   i n c l u d i n g   s t a t e l e s s ,   s t a t e f u l ,   a n d   d a t a - p r o c e s s i n g   w o r k l o a d s .   I f   a n   a p p l i c a t i o n   c a n   r u n   i n   a   c o n t a i n e r ,   i t   s h o u l d   r u n   g r e a t   o n   K u b e r n e t e s . D o e s   n o t   d e p l o y   s o u r c e   c o d e   a n d   d o e s   n o t   b u i l d   y o u r   a p p l i c a t i o n .   C o n t i n u o u s   I n t e g r a t i o n ,   D e l i v e r y ,   a n d   D e p l o y m e n t   ( C I / C D )   w o r k f l o w s


Question: What is Historical context for Kubernetes?

Answer: L e t ' s   t a k e   a   l o o k   a t   w h y   K u b e r n e t e s   i s   s o   u s e f u l   b y   g o i n g   b a c k   i n   t i m e .   T r a d i t i o n a l   d e p l o y m e n t   e r a :   E a r l y   o n ,   o r g a n i z a t i o n s   r a n   a p p l i c a t i o n s   o n   p h y s i c a l   s e r v e r s .   T h e r e   w a s   n o   w a y   t o   d e f i n e   r e s o u r c e   b o u n d a r i e s   f o r   a p p l i c a t i o n s   i n   a   p h y s i c a l   s e r v e r ,   a n d   t h i s   c a u s e d   r e s o u r c e   a l l o c a t i o n   i s s u e s .   F o r   e x a m p l e ,   i f   m u l t i p l e   a p p l i c a t i o n s   r u n   o n   a   p h y s i c a l   s e r v e r ,   t h e r e   c a n   b e   i n s t a n c e s   w h e r e   o n e   a p p l i c a t i o n   w o u l d   t a k e   u p   m o s t   o f   t h e   r e s o u r c e s ,   a n d   a s   a   r e s u l t ,   t h e   o t h e r   a p p l i c a t i o n s   w o u l d   u n d e r p e r f o r m .   A   s o l u t i o n   f o r   t h i s   w o u l d   b e   t o   r u n   e a c h   a p p l i c a t i o n   o n   a   d i f f e r e n t   p h y s i c a l   s e r v e r .   B u t   t h i s   d i d   n o t   s c a l e   a s   r e s o u r c e s   w e r e   u n d e r u t i l i z e d ,   a n d   i t   w a s   e x p e n s i v e   f o r   o r g a n i z a t i o n s   t o   m a i n t a i n   m a n y   p h y s i c a l   s e r v e r s .   V i r t u a l i z e d   d e p l o y m e n t   e r a :   A s   a   s o l u t i o n ,   v i r t u a l i z a t i o n   w a s   i n t r o d u c e d .   I t   a l l o w s   y o u   t o   r u n   m u l t i p l e   V i r t u a l   M a c h i n e s   ( V M s )   o n   a   s i n g l e   p h y s i c a l   s e r v e r ' s   C P U .   V i r t u a l i z a t i o n   a l l o w s   a p p l i c a t i o n s   t o   b e   i s o l a t e d   b e t w e e n   V M s   a n d   p r o v i d e s   a   l e v e l   o f   s e c u r i t y   a s   t h e   i n f o r m a t i o n   o f   o n e   a p p l


Question: What is What's next?

Answer: T a k e   a   l o o k   a t   t h e   K u b e r n e t e s   C o m p o n e n t s T a k e   a   l o o k   a t   t h e   T h e   K u b e r n e t e s   A P I T a k e   a   l o o k   a t   t h e   C l u s t e r   A r c h i t e c t u r e R e a d y   t o   G e t   S t a r t e d ?


Question: What is 1.1 - Kubernetes Components?

Answer: T h i s   p a g e   p r o v i d e s   a   h i g h - l e v e l   o v e r v i e w   o f   t h e   e s s e n t i a l   c o m p o n e n t s   t h a t   m a k e   u p   a   K u b e r n e t e s   c l u s t e r .   T h e   c o m p o n e n t s   o f   a   K u b e r n e t e s   c l u s t e r


Question: What is Core Components?

Answer: A   K u b e r n e t e s   c l u s t e r   c o n s i s t s   o f   a   c o n t r o l   p l a n e   a n d   o n e   o r   m o r e   w o r k e r   n o d e s .   H e r e ' s   a   b r i e f   o v e r v i e w   o f   t h e   m a i n   c o m p o n e n t s :


Question: What is Control Plane Components?

Answer: M a n a g e   t h e   o v e r a l l   s t a t e   o f   t h e   c l u s t e r :


Question: What is Node Components?

Answer: R u n   o n   e v e r y   n o d e ,   m a i n t a i n i n g   r u n n i n g   p o d s   a n d   p r o v i d i n g   t h e   K u b e r n e t e s   r u n t i m e   e n v i r o n m e n t :   Y o u r   c l u s t e r   m a y   r e q u i r e   a d d i t i o n a l   s o f t w a r e   o n   e a c h   n o d e ;   f o r   e x a m p l e ,   y o u   m i g h t   a l s o   r u n   s y s t e m d   o n   a   L i n u x   n o d e   t o   s u p e r v i s e   l o c a l   c o m p o n e n t s .


Question: What is Addons?

Answer: A d d o n s   e x t e n d   t h e   f u n c t i o n a l i t y   o f   K u b e r n e t e s .   A   f e w   i m p o r t a n t   e x a m p l e s   i n c l u d e :


Question: What is Flexibility in Architecture?

Answer: K u b e r n e t e s   a l l o w s   f o r   f l e x i b i l i t y   i n   h o w   t h e s e   c o m p o n e n t s   a r e   d e p l o y e d   a n d   m a n a g e d .   T h e   a r c h i t e c t u r e   c a n   b e   a d a p t e d   t o   v a r i o u s   n e e d s ,   f r o m   s m a l l   d e v e l o p m e n t   e n v i r o n m e n t s   t o   l a r g e - s c a l e   p r o d u c t i o n   d e p l o y m e n t s .   F o r   m o r e   d e t a i l e d   i n f o r m a t i o n   a b o u t   e a c h   c o m p o n e n t   a n d   v a r i o u s   w a y s   t o   c o n f i g u r e   y o u r   c l u s t e r   a r c h i t e c t u r e ,   s e e   t h e   C l u s t e r   A r c h i t e c t u r e   p a g e .


Question: What is 1.2 - Objects In Kubernetes?

Answer: T h i s   p a g e   e x p l a i n s   h o w   K u b e r n e t e s   o b j e c t s   a r e   r e p r e s e n t e d   i n   t h e   K u b e r n e t e s   A P I ,   a n d   h o w   y o u   c a n   e x p r e s s   t h e m   i n   . y a m l   f o r m a t .


Question: What is Understanding Kubernetes objects?

Answer: K u b e r n e t e s   o b j e c t s   a r e   p e r s i s t e n t   e n t i t i e s   i n   t h e   K u b e r n e t e s   s y s t e m .   K u b e r n e t e s   u s e s   t h e s e   e n t i t i e s   t o   r e p r e s e n t   t h e   s t a t e   o f   y o u r   c l u s t e r .   S p e c i f i c a l l y ,   t h e y   c a n   d e s c r i b e :   W h a t   c o n t a i n e r i z e d   a p p l i c a t i o n s   a r e   r u n n i n g   ( a n d   o n   w h i c h   n o d e s ) T h e   r e s o u r c e s   a v a i l a b l e   t o   t h o s e   a p p l i c a t i o n s T h e   p o l i c i e s   a r o u n d   h o w   t h o s e   a p p l i c a t i o n s   b e h a v e ,   s u c h   a s   r e s t a r t   p o l i c i e s ,   u p g r a d e s ,   a n d   f a u l t - t o l e r a n c e   A   K u b e r n e t e s   o b j e c t   i s   a   " r e c o r d   o f   i n t e n t " - - o n c e   y o u   c r e a t e   t h e   o b j e c t ,   t h e   K u b e r n e t e s   s y s t e m   w i l l   c o n s t a n t l y   w o r k   t o   e n s u r e   t h a t   t h e   o b j e c t   e x i s t s .   B y   c r e a t i n g   a n   o b j e c t ,   y o u ' r e   e f f e c t i v e l y   t e l l i n g   t h e   K u b e r n e t e s   s y s t e m   w h a t   y o u   w a n t   y o u r   c l u s t e r ' s   w o r k l o a d   t o   l o o k   l i k e ;   t h i s   i s   y o u r   c l u s t e r ' s   d e s i r e d   s t a t e .   T o   w o r k   w i t h   K u b e r n e t e s   o b j e c t s — w h e t h e r   t o   c r e a t e ,   m o d i f y ,   o r   d e l e t e   t h e m — y o u ' l l   n e e d   t o   u s e   t h e   K u b e r n e t e s   A P I .   W h e n   y o u   u s e   t h e   k u b e c t l   c o m m a n d - l i n e   i n t e r f a c e ,   f o r   e x a m p l e ,   t h e   C L I   m a k e s   t h e   n e c e s s a r y   K u b e r n e t e s   A P I   c a l l s   f o r   y o u .   Y o u   c a n   a l s o   u s e   t h e   K u b e r n e t e s   A P I   d i r e c t l y   i n   y o u r   o w n   p r o g r a m s


Question: What is Object spec and status?

Answer: A l m o s t   e v e r y   K u b e r n e t e s   o b j e c t   i n c l u d e s   t w o   n e s t e d   o b j e c t   f i e l d s   t h a t   g o v e r n   t h e   o b j e c t ' s   c o n f i g u r a t i o n :   t h e   o b j e c t   s p e c   a n d   t h e   o b j e c t   s t a t u s .   F o r   o b j e c t s   t h a t   h a v e   a   s p e c ,   y o u   h a v e   t o   s e t   t h i s   w h e n   y o u   c r e a t e   t h e   o b j e c t ,   p r o v i d i n g   a   d e s c r i p t i o n   o f   t h e   c h a r a c t e r i s t i c s   y o u   w a n t   t h e   r e s o u r c e   t o   h a v e :   i t s   d e s i r e d   s t a t e .   T h e   s t a t u s   d e s c r i b e s   t h e   c u r r e n t   s t a t e   o f   t h e   o b j e c t ,   s u p p l i e d   a n d   u p d a t e d   b y   t h e   K u b e r n e t e s   s y s t e m   a n d   i t s   c o m p o n e n t s .   T h e   K u b e r n e t e s   c o n t r o l   p l a n e   c o n t i n u a l l y   a n d   a c t i v e l y   m a n a g e s   e v e r y   o b j e c t ' s   a c t u a l   s t a t e   t o   m a t c h   t h e   d e s i r e d   s t a t e   y o u   s u p p l i e d .   F o r   e x a m p l e :   i n   K u b e r n e t e s ,   a   D e p l o y m e n t   i s   a n   o b j e c t   t h a t   c a n   r e p r e s e n t   a n   a p p l i c a t i o n   r u n n i n g   o n   y o u r   c l u s t e r .   W h e n   y o u   c r e a t e   t h e   D e p l o y m e n t ,   y o u   m i g h t   s e t   t h e   D e p l o y m e n t   s p e c   t o   s p e c i f y   t h a t   y o u   w a n t   t h r e e   r e p l i c a s   o f   t h e   a p p l i c a t i o n   t o   b e   r u n n i n g .   T h e   K u b e r n e t e s   s y s t e m   r e a d s   t h e   D e p l o y m e n t   s p e c   a n d   s t a r t s   t h r e e   i n s t a n c e s   o f   y o u r   d e s i r e d   a p p l i c a t i o n - - u p d a t i n g   t h e   s t a t u s   t o   m a t c h   y o u r   s p e c .   I f   a n y   o f   t h o s e   i n s t a n c e s   s h o u l d


Question: What is Describing a Kubernetes object?

Answer: W h e n   y o u   c r e a t e   a n   o b j e c t   i n   K u b e r n e t e s ,   y o u   m u s t   p r o v i d e   t h e   o b j e c t   s p e c   t h a t   d e s c r i b e s   i t s   d e s i r e d   s t a t e ,   a s   w e l l   a s   s o m e   b a s i c   i n f o r m a t i o n   a b o u t   t h e   o b j e c t   ( s u c h   a s   a   n a m e ) .   W h e n   y o u   u s e   t h e   K u b e r n e t e s   A P I   t o   c r e a t e   t h e   o b j e c t   ( e i t h e r   d i r e c t l y   o r   v i a   k u b e c t l ) ,   t h a t   A P I   r e q u e s t   m u s t   i n c l u d e   t h a t   i n f o r m a t i o n   a s   J S O N   i n   t h e   r e q u e s t   b o d y .   M o s t   o f t e n ,   y o u   p r o v i d e   t h e   i n f o r m a t i o n   t o   k u b e c t l   i n   a   f i l e   k n o w n   a s   a   m a n i f e s t .   B y   c o n v e n t i o n ,   m a n i f e s t s   a r e   Y A M L   ( y o u   c o u l d   a l s o   u s e   J S O N   f o r m a t ) .   T o o l s   s u c h   a s   k u b e c t l   c o n v e r t   t h e   i n f o r m a t i o n   f r o m   a   m a n i f e s t   i n t o   J S O N   o r   a n o t h e r   s u p p o r t e d   s e r i a l i z a t i o n   f o r m a t   w h e n   m a k i n g   t h e   A P I   r e q u e s t   o v e r   H T T P .   H e r e ' s   a n   e x a m p l e   m a n i f e s t   t h a t   s h o w s   t h e   r e q u i r e d   f i e l d s   a n d   o b j e c t   s p e c   f o r   a   K u b e r n e t e s   D e p l o y m e n t :   a p i V e r s i o n :   a p p s / v 1   k i n d :   D e p l o y m e n t   m e t a d a t a :   n a m e :   n g i n x - d e p l o y m e n t   s p e c :   s e l e c t o r :   m a t c h L a b e l s :   a p p :   n g i n x   r e p l i c a s :   2   #   t e l l s   d e p l o y m e n t   t o   r u n   2   p o d s   m a t c h i n g   t h e   t e m p l a t e   t e m p l a t e :   m e t a d a t a :   l a b e l s :   a p p :   n g i n x   s p e c :   c o n t a i n e r s :   -   n a m e :   n g i n x   i m a g e :


Question: What is Required fields?

Answer: I n   t h e   m a n i f e s t   ( Y A M L   o r   J S O N   f i l e )   f o r   t h e   K u b e r n e t e s   o b j e c t   y o u   w a n t   t o   c r e a t e ,   y o u ' l l   n e e d   t o   s e t   v a l u e s   f o r   t h e   f o l l o w i n g   f i e l d s :   a p i V e r s i o n   -   W h i c h   v e r s i o n   o f   t h e   K u b e r n e t e s   A P I   y o u ' r e   u s i n g   t o   c r e a t e   t h i s   o b j e c t k i n d   -   W h a t   k i n d   o f   o b j e c t   y o u   w a n t   t o   c r e a t e m e t a d a t a   -   D a t a   t h a t   h e l p s   u n i q u e l y   i d e n t i f y   t h e   o b j e c t ,   i n c l u d i n g   a   n a m e   s t r i n g ,   U I D ,   a n d   o p t i o n a l   n a m e s p a c e s p e c   -   W h a t   s t a t e   y o u   d e s i r e   f o r   t h e   o b j e c t   T h e   p r e c i s e   f o r m a t   o f   t h e   o b j e c t   s p e c   i s   d i f f e r e n t   f o r   e v e r y   K u b e r n e t e s   o b j e c t ,   a n d   c o n t a i n s   n e s t e d   f i e l d s   s p e c i f i c   t o   t h a t   o b j e c t .   T h e   K u b e r n e t e s   A P I   R e f e r e n c e   c a n   h e l p   y o u   f i n d   t h e   s p e c   f o r m a t   f o r   a l l   o f   t h e   o b j e c t s   y o u   c a n   c r e a t e   u s i n g   K u b e r n e t e s .   F o r   e x a m p l e ,   s e e   t h e   s p e c   f i e l d   f o r   t h e   P o d   A P I   r e f e r e n c e .   F o r   e a c h   P o d ,   t h e   . s p e c   f i e l d   s p e c i f i e s   t h e   p o d   a n d   i t s   d e s i r e d   s t a t e   ( s u c h   a s   t h e   c o n t a i n e r   i m a g e   n a m e   f o r   e a c h   c o n t a i n e r   w i t h i n   t h a t   p o d ) .   A n o t h e r   e x a m p l e   o f   a n   o b j e c t   s p e c i f i c a t i o n   i s   t h e   s p e c   f i e l d   f o r   t h e   S t a t e f u l S e t   A P I .   F o r   S t a t e f u l S e t ,   t h e   . s p e c   f i e l d   s p e c i f i e s   t h e   S