[K8S] Pod中的容器类型、静态Pod

╰半橙微兮° 2022-09-07 03:45 209阅读 0赞

@Pod中的容器类型

（1）Infrastructure Container 基础容器  
共用pause的网络栈和存储卷，只要有pod，容器pause就会启动

在任意节点查看容器，可以看到一个Pod(可能包含一个或多个容器)对应一个pause

[root@k8s-node1 manifests]# docker ps
    CONTAINER ID   IMAGE                                               COMMAND                  CREATED        STATUS        PORTS     NAMES
    37c42e23779d   nginx                                               "/docker-entrypoint.…"   10 hours ago   Up 10 hours             k8s_nginx_test-probe-766bcd6cf-tx52m_default_5e84e70e-402d-4c5d-91ad-5ca209fb230b_0
    cf2e8f0fd3a4   nginx                                               "/docker-entrypoint.…"   10 hours ago   Up 10 hours             k8s_nginx_test-probe-766bcd6cf-p9f8p_default_0ae8718a-062b-4461-86c5-9f2e534bc8b7_0
    630c2e8df100   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 10 hours ago   Up 10 hours             k8s_POD_test-probe-766bcd6cf-p9f8p_default_0ae8718a-062b-4461-86c5-9f2e534bc8b7_0
    bd0aa978a8d8   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 10 hours ago   Up 10 hours             k8s_POD_test-probe-766bcd6cf-tx52m_default_5e84e70e-402d-4c5d-91ad-5ca209fb230b_0
    e5ca0e01ba6c   nginx                                               "/docker-entrypoint.…"   11 hours ago   Up 11 hours             k8s_nginx_pod-01-f6cdbd6c9-p9t7g_aliang-cka_74f4b7c9-0c26-425b-8eb2-8e506b9b40cf_9
    97b58cab095a   1470783b1474                                        "start_runit"            11 hours ago   Up 11 hours             k8s_calico-node_calico-node-q6qxm_kube-system_fde756c0-dea4-4e43-b0fd-bf76ff758bf4_15
    ea7c0a45c66e   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 11 hours ago   Up 11 hours             k8s_POD_pod-01-f6cdbd6c9-p9t7g_aliang-cka_74f4b7c9-0c26-425b-8eb2-8e506b9b40cf_9
    e9a7ba202fab   10cc881966cf                                        "/usr/local/bin/kube…"   11 hours ago   Up 11 hours             k8s_kube-proxy_kube-proxy-clmzc_kube-system_89972005-0074-4aad-a9f6-d9928e80e0b8_15
    905d12edd8ce   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 11 hours ago   Up 11 hours             k8s_POD_calico-node-q6qxm_kube-system_fde756c0-dea4-4e43-b0fd-bf76ff758bf4_15
    3f59d74236b4   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 11 hours ago   Up 11 hours             k8s_POD_kube-proxy-clmzc_kube-system_89972005-0074-4aad-a9f6-d9928e80e0b8_15
    [root@k8s-node1 manifests]#

（2）InitContainer 初始化容器  
先于应用容器执行，用于初始化工作，执行完就结束  
可用于如下场景  
环境检查 -> 确保应用容器依赖的服务启动后再启动应用容器  
初始化配置 -> 为应用容器准备配置文件

（3）Containers 业务容器

@静态Pod

静态Pod路径参数

[root@k8s-master ~]# grep static /var/lib/kubelet/config.yaml
    staticPodPath: /etc/kubernetes/manifests
    [root@k8s-master ~]#

将pod yaml放到路径/etc/kubernetes/manifests会由kubelet自动创建

[root@k8s-master manifests]# pwd
    /etc/kubernetes/manifests
    [root@k8s-master manifests]# ls -l
    total 16
    -rw------- 1 root root 2232 Jul 26 00:01 etcd.yaml
    -rw------- 1 root root 3340 Jul 26 00:01 kube-apiserver.yaml
    -rw------- 1 root root 2828 Aug  7 09:59 kube-controller-manager.yaml
    -rw------- 1 root root 1414 Aug  7 09:59 kube-scheduler.yaml
    [root@k8s-master manifests]#

【例】/root/teststaticpod.yaml内容如下

apiVersion: v1
    kind: Pod
    metadata:
      name: testpod
    spec:
      containers:
      - image: nginx
        name: testpod

将其放置到节点k8s-master的路径/etc/kubernetes/manifests,可以看到新拉起了一个Pod,其名称的后半部分是节点名称

[root@k8s-master manifests]# kubectl get pod -o wide
    No resources found in default namespace.
    [root@k8s-master manifests]#
    [root@k8s-master manifests]# mv /root/teststaticpod.yaml ./
    [root@k8s-master manifests]#
    [root@k8s-master manifests]# kubectl get pod -o wide
    NAME                 READY   STATUS    RESTARTS   AGE   IP               NODE         NOMINATED NODE   READINESS GATES
    testpod-k8s-master   1/1     Running   0          5s    10.244.235.226   k8s-master   <none>           <none>
    [root@k8s-master manifests]#

再将该Pod的yaml文件挪走,可以看到刚才拉起的Pod没了

[root@k8s-master manifests]# mv teststaticpod.yaml /root
    [root@k8s-master manifests]#
    [root@k8s-master manifests]# kubectl get pod -o wide
    No resources found in default namespace.
    [root@k8s-master manifests]#