Kubernetes基础：指定容器执行时使用的参数

柔光的暖阳◎ 2023-07-03 08:14 51阅读 0赞

前面的文章中介绍了使用Deployment和Service启动nginx服务的方法，为了后续继续介绍Ingress和其他功能，这里需要确定访问服务时能够返回不同的信息，这篇文章继续介绍一下如何指定容器执行时使用的参数。

# 使用Deployment + Service #

使用Deployment和Service，能够让用户直接访问到暴露出来的服务，使用这种方式启动的nginx服务的示例如下所示：

*  [https://liumiaocn.blog.csdn.net/article/details/104165220][https_liumiaocn.blog.csdn.net_article_details_104165220]

在此基础之上，我们进行一些扩展，首先启动nginx服务并确认Pod

[root@host131 nginx]# ls
    deployment.yml  service.yml
    [root@host131 nginx]# kubectl create -f .
    deployment.apps/nginx-deployment created
    service/nginx-service created
    [root@host131 nginx]# 
    [root@host131 nginx]# kubectl get service nginx-service -o wide
    NAME            TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE   SELECTOR
    nginx-service   NodePort   10.254.131.2   <none>        80:30000/TCP   22s   app=nginx-app
    [root@host131 nginx]# kubectl get pod |grep nginx
    nginx-deployment-7c5b8fc568-9g4jb   1/1     Running   0          31s
    [root@host131 nginx]#

进入到pod之后，修改nginx的index.html文件

[root@host131 nginx]# kubectl exec -it nginx-deployment-7c5b8fc568-9g4jb sh
    / # cd /usr/share/nginx/html/
    /usr/share/nginx/html # ls
    50x.html    index.html
    /usr/share/nginx/html # vi index.html 
    /usr/share/nginx/html # cat index.html 
    <!DOCTYPE html>
    <html>
    <body>
    <title>Welcome to use nginx</title>>
    
    <script> document.write("location: " + window.location.href + "</br>"); document.write("hostname: " + window.location.hostname + "</br>"); document.write("host: " + window.location.host + "</br>"); document.write("pathname: " + window.location.pathname + "</br>"); document.write("protocol: " + window.location.protocol + "</br>"); document.write("port: " + window.location.port + "</br>"); </script>
    
    </body>
    </html>
    /usr/share/nginx/html #

结果确认  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9saXVtaWFvY24uYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70]  
因为JS是运行线沙箱中的，所以获取操作系统的hostname之类的信息，使用直接的方式几乎是不太可能。所以这里直接使用之前做过的一个tornado的镜像。

# Docker方式的参数传递 #

比如使用如下镜像，可以在启动的时候传递参数：

liumiaocn:~ liumiao$ docker run -d -p 7001:8080 liumiaocn/tornado:latest python /usr/local/bin/daemon.py "in host1"
    814d29e3391227349e7cde5c61f55e90a0cecdc40779ec0ee5834a1dab28daa2
    liumiaocn:~ liumiao$ docker run -d -p 7002:8080 liumiaocn/tornado:latest python /usr/local/bin/daemon.py "in host2"
    d4b0115d7dce5a4cf73e0213a6096cee46240e9d2ba6c2b7752d5ec63879f3ab
    liumiaocn:~ liumiao$

执行确认如下所示

liumiaocn:~ liumiao$ curl http://localhost:7001
    Hello, Service :in host1
    liumiaocn:~ liumiao$ 
    liumiaocn:~ liumiao$ curl http://localhost:7002
    Hello, Service :in host2
    liumiaocn:~ liumiao$

这是使用Docker方式进行参数的传递方式，而如果是用Deployment应该怎样做呢

# Deployment中指定容器执行时使用的参数 #

使用同样的方式使用如下Deployment和Service

[root@host131 nginx]# ls
    deployment.yml  service.yml
    [root@host131 nginx]# cat deployment.yml 
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: tornado-deployment
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: tornado-app
      template:
        metadata:
          labels:
            app: tornado-app
        spec:
          containers:
          - name: tornado-host
            image: liumiaocn/tornado:latest
            command: ["python"]
            args: ["/usr/local/bin/daemon.py", "in host1"]
            ports:
            - containerPort: 80
    ...
    [root@host131 nginx]# cat service.yml 
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: tornado-service
      labels:
        app: tornado-service-app
    spec:
      type: NodePort
      ports:
      - port: 8080
        nodePort: 30000
      selector:
        app: tornado-app
    ...
    [root@host131 nginx]#

创建服务

[root@host131 nginx]# kubectl create -f .
    deployment.apps/tornado-deployment created
    service/tornado-service created
    [root@host131 nginx]# 
    [root@host131 nginx]# kubectl get pods -o wide |grep tornado
    tornado-deployment-69c57569c6-d28q8   1/1     Running   0          9s    10.254.152.6   192.168.163.131   <none>           <none>
    [root@host131 nginx]# kubectl get service -o wide |grep tornado
    tornado-service   NodePort    10.254.203.121   <none>        8080:30000/TCP   25s     app=tornado-app
    [root@host131 nginx]#

*  结果确认

[root@host131 nginx]# curl http://10.254.203.121:8080
    Hello, Service :in host1
    [root@host131 nginx]# 
    [root@host131 nginx]# curl http://192.168.163.131:30000
    Hello, Service :in host1
    [root@host131 nginx]#

*  浏览器结果确认  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9saXVtaWFvY24uYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70 1]

# 其他格式 #

Deployment传递参数，还可以写成如下信息

[root@host131 nginx]# cat deployment.yml 
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: tornado-deployment
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: tornado-app
      template:
        metadata:
          labels:
            app: tornado-app
        spec:
          containers:
          - name: tornado-host
            image: liumiaocn/tornado:latest
            command:
              - python
            args: 
              - /usr/local/bin/daemon.py
              - in host1
            ports:
            - containerPort: 80
    ...
    [root@host131 nginx]#

[https_liumiaocn.blog.csdn.net_article_details_104165220]: https://liumiaocn.blog.csdn.net/article/details/104165220
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