Kubernetes 初始化容器及静态Pod和标签注释

初始化容器

kubernetes 1.3版本引入了init container 初始化容器特性。主要用于在启动应用容器（app container）前来启动一个或多个初始化容器，作为应用容器的一个基础。
init 1 --> init 2 --> 所有的初始化容器加载运行完成后，才能运行应用容器 --> app container

实战举例

# 查看要修改的内核参数
[root@kmaster ~]# sysctl -a|grep vm.overcommit_ratio
vm.overcommit_ratio = 50

# 输出yaml文件
[root@kmaster ~]# kubectl run initpod --image centos --image-pull-policy IfNotPresent --dry-run=client -o yaml -- sleep 3600> /root/pod_yaml/initpod.yaml
[root@kmaster ~]# cd pod_yaml/
[root@kmaster pod_yaml]# ls
initpod.yaml

# 修改yaml文件
[root@kmaster pod_yaml]# vim initpod.yaml 
[root@kmaster pod_yaml]# cat initpod.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: initpod
  name: initpod
spec:
  containers:
  - args:
    - sleep
    - "3600"
    image: centos
    imagePullPolicy: IfNotPresent
    name: initpod
    resources: {}
  initContainers:
  - name: initpod1
    image: alpine
    imagePullPolicy: IfNotPresent
    command: ["/sbin/sysctl","-w","vm.overcommit_ratio=55"]
    securityContext:
      privileged: true
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

# 编排Pod
[root@kmaster pod_yaml]# kubectl apply -f initpod.yaml 
pod/initpod created

# 查看Pod
[root@kmaster pod_yaml]# kubectl get pod -o wide 
NAME      READY   STATUS    RESTARTS   AGE   IP              NODE     NOMINATED NODE   READINESS GATES
initpod   1/1     Running   0          14s   10.244.69.210   knode2   <none>           <none>

# 查看knode2上是否已经修改
[root@knode2 ~]# sysctl -a|grep vm.overcommit_ratio
vm.overcommit_ratio = 55

# 输出yaml文件
[root@kmaster pod_yaml]# kubectl run initpod2 --image centos --image-pull-policy IfNotPresent --dry-run=client -o yaml -- sleep 3600 > /root/pod_yaml/initpod2.yaml
[root@kmaster pod_yaml]# ls
initpod2.yaml  initpod.yaml

# 修改yaml文件
[root@kmaster pod_yaml]# vim initpod2.yaml 
[root@kmaster pod_yaml]# cat initpod2.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: initpod2
  name: initpod2
spec:
  containers:
  - args:
    - sleep
    - "3600"
    image: centos
    imagePullPolicy: IfNotPresent
    name: initpod2
    resources: {}
    volumeMounts:
    - name: testdir
      mountPath: /test
  initContainers:
  - name: alpine
    image: alpine
    imagePullPolicy: IfNotPresent
    command: ["sh","-c","echo 123 > /initest/test.txt"]
    volumeMounts:
    - name: testdir
      mountPath: /initest
  volumes:
  - name: testdir
    emptyDir: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

# 编排Pod
[root@kmaster pod_yaml]# kubectl apply -f initpod2.yaml 
pod/initpod2 created

# 查看状态
[root@kmaster pod_yaml]# kubectl get pod -o wide 
NAME       READY   STATUS    RESTARTS   AGE     IP               NODE     NOMINATED NODE   READINESS GATES
initpod    1/1     Running   0          32m     10.244.69.210    knode2   <none>           <none>
initpod2   1/1     Running   0          2m25s   10.244.195.149   knode1   <none>           <none>

# 进入容器查看是否挂载成功
[root@kmaster pod_yaml]# kubectl exec -it pods/initpod2 -- bash
Defaulted container "initpod2" out of: initpod2, alpine (init)
[root@initpod2 /]# cd /test/
[root@initpod2 test]# ls
test.txt
[root@initpod2 test]# cat test.txt 
123
[root@initpod2 test]#

静态Pod

注意不要在master上操作，因为master上跑的是集群核心静态pod，在node上去做

# 创建一个目录
[root@knode1 ~]# mkdir /etc/kubernetes/test

# 编辑配置文件
[root@knode1 ~]# vim /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
[root@knode1 ~]# cat /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf 
# 在环境变量参数里面加上 --pod-manifest-path=/etc/kubernetes/test ，指向创建的目录 
# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml --pod-manifest-path=/etc/kubernetes/test"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

# 重启k8s
[root@knode1 ~]# systemctl daemon-reload 
[root@knode1 ~]# systemctl restart kubelet.service 

# 在test目录里面编写yaml文件
[root@knode1 ~]# cd /etc/kubernetes/test
[root@knode1 test]# kubectl run pod1 --image nginx --image-pull-policy IfNotPresent --dry-run=client -o yaml > pod1.yaml
[root@knode1 test]# cat pod1.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: pod1
  name: pod1
spec:
  containers:

  - image: nginx
    imagePullPolicy: IfNotPresent
    name: pod1
    resources: {}
      dnsPolicy: ClusterFirst
      restartPolicy: Always
    status: {}
    [root@knode1 test]# 
    [root@knode1 test]# ls
    pod1.yaml

# 去master上查询，就会看到一个静态pod
[root@kmaster ~]# kubectl get pod
NAME          READY   STATUS              RESTARTS   AGE
pod1-knode1   0/1     ContainerCreating   0          14s

# 一旦移走了yaml文件，静态pod也将被删除
[root@knode1 test]# mv pod1.yaml /tmp/
[root@knode1 test]# ls
[root@kmaster ~]# kubectl get pod -o wide
No resources found in kongshuo namespace.

定义主机标签

创建标签并调度指定主机

# 为主机定义标签
[root@kmaster ~]# kubectl label nodes knode1 aaa=knode1
node/knode1 labeled
[root@kmaster ~]# kubectl get nodes knode1 --show-labels 
NAME     STATUS   ROLES    AGE   VERSION   LABELS
knode1   Ready    <none>   4d    v1.26.0   aaa=knode1,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode1,kubernetes.io/os=linux

[root@kmaster ~]# kubectl label nodes knode2 bbb=knode2
node/knode2 labeled
[root@kmaster ~]# kubectl get nodes knode2 --show-labels 
NAME     STATUS   ROLES    AGE   VERSION   LABELS
knode2   Ready    <none>   4d    v1.26.0   bbb=knode2,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode2,kubernetes.io/os=linux

# 测试Pod指定调度主机knode1
[root@kmaster ~]# kubectl run pod1 --image nginx --image-pull-policy IfNotPresent --dry-run=client -o yaml > pod1.yaml
[root@kmaster ~]# vim pod1.yaml 
[root@kmaster ~]# cat pod1.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: pod1
  name: pod1
spec:
  nodeSelector:
    aaa: knode1      
  containers:
  - image: nginx
    imagePullPolicy: IfNotPresent
    name: pod1
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}
[root@kmaster ~]# kubectl apply -f pod1.yaml 
pod/pod1 created
[root@kmaster ~]# kubectl get pod -o wide 
NAME   READY   STATUS    RESTARTS   AGE   IP               NODE     NOMINATED NODE   READINESS GATES
pod1   1/1     Running   0          31s   10.244.195.150   knode1   <none>           <none>

# 测试Pod指定调度主机knode2
[root@kmaster ~]# kubectl run pod2 --image nginx --image-pull-policy IfNotPresent --dry-run=client -o yaml > pod2.yaml
[root@kmaster ~]# vim pod2.yaml 
[root@kmaster ~]# cat pod2.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: pod2
  name: pod2
spec:
  nodeSelector:
    bbb: knode2
  containers:
  - image: nginx
    imagePullPolicy: IfNotPresent
    name: pod2
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}
[root@kmaster ~]# kubectl apply -f pod2.yaml 
pod/pod2 created
[root@kmaster ~]# kubectl get pod -o wide 
NAME   READY   STATUS    RESTARTS   AGE    IP               NODE     NOMINATED NODE   READINESS GATES
pod1   1/1     Running   0          3m4s   10.244.195.150   knode1   <none>           <none>
pod2   1/1     Running   0          9s     10.244.69.211    knode2   <none>           <none>

删除主机标签

[root@kmaster ~]# kubectl get nodes/knode1 --show-labels 
NAME     STATUS   ROLES    AGE    VERSION   LABELS
knode1   Ready    <none>   4d1h   v1.26.0   aaa=knode1,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode1,kubernetes.io/os=linux
[root@kmaster ~]# kubectl label nodes/knode1 aaa-
node/knode1 unlabeled
[root@kmaster ~]# kubectl get nodes/knode1 --show-labels 
NAME     STATUS   ROLES    AGE    VERSION   LABELS
knode1   Ready    <none>   4d1h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode1,kubernetes.io/os=linux

[root@kmaster ~]# kubectl get nodes/knode2 --show-labels 
NAME     STATUS   ROLES    AGE    VERSION   LABELS
knode2   Ready    <none>   4d1h   v1.26.0   bbb=knode2,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode2,kubernetes.io/os=linux
[root@kmaster ~]# kubectl label nodes/knode2 bbb-
node/knode2 unlabeled
[root@kmaster ~]# kubectl get nodes/knode2 --show-labels 
NAME     STATUS   ROLES    AGE    VERSION   LABELS
knode2   Ready    <none>   4d1h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode2,kubernetes.io/os=linux

定义标签Pod

创建标签

# 为Pod定义标签
[root@kmaster ~]# kubectl get pods/pod1 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE     LABELS
pod1   1/1     Running   0          4m17s   run=pod1
[root@kmaster ~]# kubectl label pods/pod1 aaa=pod1
pod/pod1 labeled
[root@kmaster ~]# kubectl get pods/pod1 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE   LABELS
pod1   1/1     Running   0          10m   aaa=pod1,run=pod1

[root@kmaster ~]# kubectl get pods/pod2 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE     LABELS
pod2   1/1     Running   0          9m27s   run=pod2
[root@kmaster ~]# kubectl label pods/pod2 bbb=pod2
pod/pod2 labeled
[root@kmaster ~]# kubectl get pods/pod2 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE     LABELS
pod2   1/1     Running   0          9m33s   bbb=pod2,run=pod2

删除标签

[root@kmaster ~]# kubectl get pods/pod1 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE   LABELS
pod1   1/1     Running   0          15m   aaa=pod1,run=pod1
[root@kmaster ~]# kubectl label pods/pod1 aaa-
pod/pod1 unlabeled
[root@kmaster ~]# kubectl get pods/pod1 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE   LABELS
pod1   1/1     Running   0          15m   run=pod1

[root@kmaster ~]# kubectl get pods/pod2 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE   LABELS
pod2   1/1     Running   0          13m   bbb=pod2,run=pod2
[root@kmaster ~]# kubectl label pods/pod2 bbb-
pod/pod2 unlabeled
[root@kmaster ~]# kubectl get pods/pod2 --show-labels 
NAME   READY   STATUS    RESTARTS   AGE   LABELS
pod2   1/1     Running   0          13m   run=pod2

定义主机ROLES标签

[root@kmaster ~]# kubectl get nodes --show-labels 
NAME      STATUS   ROLES           AGE   VERSION   LABELS
kmaster   Ready    control-plane   19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=kmaster,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node.kubernetes.io/exclude-from-external-load-balancers=
knode1    Ready    <none>          19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode1,kubernetes.io/os=linux
knode2    Ready    <none>          19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode2,kubernetes.io/os=linux
# 定义master标签并删除control-plane
[root@kmaster ~]# kubectl label nodes kmaster node-role.kubernetes.io/kmaster=
node/kmaster labeled
[root@kmaster ~]# kubectl get nodes kmaster --show-labels 
NAME      STATUS   ROLES                   AGE   VERSION   LABELS
kmaster   Ready    control-plane,kmaster   19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=kmaster,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node-role.kubernetes.io/kmaster=,node.kubernetes.io/exclude-from-external-load-balancers=
[root@kmaster ~]# kubectl label nodes kmaster node-role.kubernetes.io/control-plane-
node/kmaster unlabeled
[root@kmaster ~]# kubectl get nodes kmaster --show-labels 
NAME      STATUS   ROLES     AGE   VERSION   LABELS
kmaster   Ready    kmaster   19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=kmaster,kubernetes.io/os=linux,node-role.kubernetes.io/kmaster=,node.kubernetes.io/exclude-from-external-load-balancers=
# 定义node1标签
[root@kmaster ~]# kubectl label nodes knode1 node-role.kubernetes.io/knode1=
node/knode1 labeled
[root@kmaster ~]# kubectl get nodes knode1 --show-labels 
NAME     STATUS   ROLES    AGE   VERSION   LABELS
knode1   Ready    knode1   19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode1,kubernetes.io/os=linux,node-role.kubernetes.io/knode1=
# 定义node2标签
[root@kmaster ~]# kubectl label nodes knode2 node-role.kubernetes.io/knode2=
node/knode2 labeled
[root@kmaster ~]# kubectl get nodes knode2 --show-labels 
NAME     STATUS   ROLES    AGE   VERSION   LABELS
knode2   Ready    knode2   19h   v1.26.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=knode2,kubernetes.io/os=linux,node-role.kubernetes.io/knode2=
# 定义完成
[root@kmaster ~]# kubectl get nodes
NAME      STATUS   ROLES     AGE   VERSION
kmaster   Ready    kmaster   19h   v1.26.0
knode1    Ready    knode1    19h   v1.26.0
knode2    Ready    knode2    19h   v1.26.0

添加Annotations注释

[root@kmaster ~]# kubectl describe pods pod222 |head -20
Name:             pod222
Namespace:        kongshuo
Priority:         0
Service Account:  default
Node:             knode1/192.168.239.144
Start Time:       Fri, 08 Sep 2023 03:01:43 -0400
Labels:           run=pod222
Annotations:      cni.projectcalico.org/containerID: 3717208f3174b12a7e339d6b1bef0dbd984598916f7462f457c222d2347469a4
                  cni.projectcalico.org/podIP: 10.244.195.141/32
                  cni.projectcalico.org/podIPs: 10.244.195.141/32
Status:           Running
IP:               10.244.195.141
IPs:
  IP:  10.244.195.141
Containers:
  pod222:
    Container ID:   containerd://91ab8d14ea2b641868c7703d2c58f047f5ad037a7162eb2ac7fc8c919532f60b
    Image:          nginx
    Image ID:       docker.io/library/nginx@sha256:b437ad7a4d9964a2d5cbee850946380722082d04a1a731275a583825d68eec92
    Port:           <none>
[root@kmaster ~]# kubectl annotate pods pod222 zhe.shi.yi.tiao.zhu.shi=
pod/pod222 annotated
[root@kmaster ~]# kubectl describe pods pod222 |head -20
Name:             pod222
Namespace:        kongshuo
Priority:         0
Service Account:  default
Node:             knode1/192.168.239.144
Start Time:       Fri, 08 Sep 2023 03:01:43 -0400
Labels:           run=pod222
Annotations:      cni.projectcalico.org/containerID: 3717208f3174b12a7e339d6b1bef0dbd984598916f7462f457c222d2347469a4
                  cni.projectcalico.org/podIP: 10.244.195.141/32
                  cni.projectcalico.org/podIPs: 10.244.195.141/32
                  zhe.shi.yi.tiao.zhu.shi: 
Status:           Running
IP:               10.244.195.141
IPs:
  IP:  10.244.195.141
Containers:
  pod222:
    Container ID:   containerd://91ab8d14ea2b641868c7703d2c58f047f5ad037a7162eb2ac7fc8c919532f60b
    Image:          nginx
    Image ID:       docker.io/library/nginx@sha256:b437ad7a4d9964a2d5cbee850946380722082d04a1a731275a583825d68eec92

posted @ 2023-05-22 14:06 kongshuo 阅读(107) 评论(0) 编辑收藏举报

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Kubernetes 初始化容器及静态Pod和标签注释

初始化容器

实战举例

静态Pod

定义主机标签

创建标签并调度指定主机

删除主机标签

定义标签Pod

创建标签

删除标签

定义主机ROLES标签

添加Annotations注释

公告

常用链接

最新随笔

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