"Original" k8s Source Analysis-----Kubelet (3) CONTAINERGC

I space link: http://user.qzone.qq.com/29185807/blog/1460080827

Source code for k8s v1.1.1 stable version

2.2 CONTAINERGC1. Parameters

code in K8s.io\kubernetes\cmd\kubelet\app in

struct-Body variables

Type Kubeletserver struct {

...

Minimumgcage time. Duration

Maxcontainercount int

Maxperpodcontainercount int

...

}

Default parameters

Func newkubeletserver () *kubeletserver {

Return &kubeletserver{

...

Minimumgcage:1 * time. Minute,

MAXCONTAINERCOUNT:100,

Maxperpodcontainercount:2,

...

}

}

Flag parameter

Func (S *kubeletserver) addflags (fs *pflag. Flagset) {

...

Fs. Durationvar (&s.minimumgcage, "minimum-container-ttl-duration", s.minimumgcage, "minimum age for a finished  Container before it is garbage collected. Examples: ' 300ms ', ' 10s ' or ' 2h45m ')

Fs. Intvar (&s.maxcontainercount, "Maximum-dead-containers", S.maxcontainercount, "Maximum number of old instances of  Containers to retain globally.  Each container takes up some disk space. default:100. ")

Fs. Intvar (&s.maxperpodcontainercount, "Maximum-dead-containers-per-container", S.maxperpodcontainercount, "  Maximum number of old instances to retain per container.  Each container takes up some disk space. Default:2. ")

...

}

Minimumgcage  :  minimum-container-ttl-duration The TTL of the container instance that has been stopped on the system for the time to live.

Maxcontainercount : maximum-dead-containers the maximum number of stopped container instances that can be saved in the system.

Maxperpodcontainercount : Maximum-dead-containers-per-container The maximum number of stopped instances per container that are saved in the system.

2. Passing Parameters

In 1 we see that the parameters have been built. So, how did that pass?

the code is still in K8s.io\kubernetes\cmd\kubelet\app in

in the func (S *kubeletserver) Kubeletconfig () (*kubeletconfig, error) {

...

Return &kubeletconfig{

...

Maxcontainercount:s.maxcontainercount,

Maxperpodcontainercount:s.maxperpodcontainercount,

Minimumgcage:s.minimumgcage,

...

}

}

has built a Kubeletconfig

Continue delivery

has built a Kubelet . Containergcpolicy

and passed it to the Newmainkubelet in

called at the end of the function . k . startgarbagecollection ()

3. Work Flow3.1 Build

code in K8s.io\kubernetes\pkg\kubelet in \kubelet.go

Func Newmainkubelet (

And then

The whole process was built.

and then we know from 2 that we finally called the following code. Regular execution of garbagecollect

3.2 Specific Processes

code in K8s.io\kubernetes\pkg\kubelet \ Container_gc.go in

Let's look at the structure.

let's see . evictablecontainers function, which is used to get container information

Below is Garbagecollect , the container information is obtained first, and then the container is recycled based on the previously passed parameter values .

Hao Haohua

QQ Crescent 29185807

April 8, 2016

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"Original" k8s Source Analysis-----Kubelet (3) CONTAINERGC