应用部署，运行与管理（一）

暴露容器服务

pod对象的IP地址仅在集群内部可达，无法直接接收集群外部客户端请求流量。

在前面我们已经实操了通过Service资源镜像服务暴露的情况，（NodePort是通过所有节点暴露服务的）

现在不考虑Service资源暴露：常用方式有2种：一是在其运行的节点上进行端口映射；二是让Pod共享器所在的工作节点的网络名称空间，应用进程将直接监听工作节点IP地址和协议端口。

下面创建一个httpd服务示例

[root@k8s-master01 yaml]# cat pod-using-hostport.yaml

apiVersion: v1
kind: Pod
metadata:
  name: pod-using-hostport
  namespace: dev
spec:
  containers:
  - name: httpd
    image: httpd
    imagePullPolicy: Always
    ports:
    - name: http
      containerPort: 80
      protocol: TCP
      hostPort: 10080

containerPort：必选字段，指定在pod对象的IP地址上暴露的容器端口
name：当前端口的名称识别，必选符合规范并且在当前pod内具有唯一性
protocol：端口相关的协议；其值仅有TCP、SCTP、UDP。
hostPort：主机端口，它将接收到的请求通过NTP机制转发至containerport字段指定的容器端口
hostIP：主机端口要绑定的主机ip，默认是主机间所有可用的IP地址

上面的资源配置清单示例中定义的httpd容器指定了要暴露容器上TCP协议的80端口，并将之命名为http，该容器可通过工作节点的10080端口接入集群外部客户端的请求

[root@k8s-master01 yaml]# kubectl apply -f pod-using-hostport.yaml -n dev
pod/pod-using-hostport created

[root@k8s-master01 yaml]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
pod-nginx-68dc879f46-fcwxh 1/1 Running 0 142m
pod-nginx-68dc879f46-htp2z 1/1 Running 0 142m
pod-nginx-68dc879f46-kzhb5 1/1 Running 0 145m
pod-nginx-68dc879f46-rblxg 1/1 Running 0 142m
pod-using-hostport 1/1 Running 0 96s

[root@k8s-master01 yaml]# kubectl describe pods/pod-using-hostport -n dev | grep "^Node:"
Node: k8s-node01/10.122.138.245 #调度的工作节点

[root@k8s-master01 yaml]# curl 10.122.138.245:10080
<html><body><h1>It works!</h1></body></html>

配置Pod使用节点网络

[root@k8s-master01 yaml]# cat pod-using-hostnetwork.yaml

apiVersion: v1
kind: Pod
metadata:
  name: pod-using-hostnetwork
  namespace: dev
spec:
  containers:
  - name: httpd
    image: httpd
    imagePullPolicy: Always
  hostNetwork: true

[root@k8s-master01 yaml]# kubectl apply -f pod-using-hostnetwork.yaml -n dev
pod/pod-using-hostnetwork created

[root@k8s-master01 yaml]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
pod-nginx-68dc879f46-fcwxh 1/1 Running 0 3h19m
pod-nginx-68dc879f46-htp2z 1/1 Running 0 3h19m
pod-nginx-68dc879f46-kzhb5 1/1 Running 0 3h22m
pod-nginx-68dc879f46-rblxg 1/1 Running 0 3h19m
pod-using-hostnetwork 1/1 Running 0 78s
pod-using-hostport 1/1 Running 0 58m

[root@k8s-master01 yaml]# kubectl describe pod/pod-using-hostnetwork -n dev
Name:         pod-using-hostnetwork
Namespace:    dev
Priority:     0
Node:         k8s-node03/10.122.138.247
Start Time:   Sun, 15 Aug 2021 16:01:26 +0800
Labels:       <none>
Annotations:  <none>
Status:       Running
IP:           10.122.138.247
IPs:
  IP:  10.122.138.247
Containers:
  httpd:
    Container ID:   docker://9c1f28f411c59b0273cb6c0b392cd308ef69dd5a6d8ac495bce1088db0107b88
    Image:          httpd
    Image ID:       docker-pullable://httpd@sha256:eacdd6c7419ab95b43a258321fc6b38cf56004de4f6a952fc0d96a12730e04de
    Port:           <none>
    Host Port:      <none>
    State:          Running
      Started:      Sun, 15 Aug 2021 16:01:30 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-wt6qh (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-wt6qh:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-wt6qh
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason     Age    From                 Message
  ----    ------     ----   ----                 -------
  Normal  Scheduled  3m21s                       Successfully assigned dev/pod-using-hostnetwork to k8s-node03
  Normal  Pulling    3m21s  kubelet, k8s-node03  Pulling image "httpd"
  Normal  Pulled     3m18s  kubelet, k8s-node03  Successfully pulled image "httpd" in 2.69434777s
  Normal  Created    3m18s  kubelet, k8s-node03  Created container httpd
  Normal  Started    3m18s  kubelet, k8s-node03  Started container httpd

[root@k8s-master01 yaml]# curl k8s-node03
<html><body><h1>It works!</h1></body></html>

posted @ 2021-08-15 15:49 拥抱大海，面向天空阅读(44) 评论(0) 收藏举报

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