Microk8s 入口返回 502

Posted 2023-03-16

【中文标题】Microk8s 入口返回 502

【英文标题】：Microk8s Ingress returns 502

【发布时间】：2021-12-01 13:51:50

【问题描述】：

我是 Kubernetes 的新手，正在尝试在我的 Ubuntu 20.04 上使用 Kubernetes 做一个简单的项目来连接 mysql 和 phpMyAdmin。我创建了所需的组件，这里是组件。

mysql.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql-deployment
  labels:
    app: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
        - name: mysql
          image: mysql
          ports:
            - containerPort: 3306
          env:
            - name: MYSQL_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mysql-secret
                  key: mysql-root-password
            - name: MYSQL_USER
              valueFrom:
                secretKeyRef:
                  name: mysql-secret
                  key: mysql-user-username
            - name: MYSQL_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mysql-secret
                  key: mysql-user-password
            - name: MYSQL_DATABASE
              valueFrom:
                configMapKeyRef:
                  name: mysql-configmap
                  key: mysql-database
---
apiVersion: v1
kind: Service
metadata:
  name: mysql-service
spec:
  selector:
    app: mysql
  ports:
    - protocol: TCP
      port: 3306
      targetPort: 3306

phpmyadmin.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: phpmyadmin
  labels:
    app: phpmyadmin
spec:
  replicas: 1
  selector:
    matchLabels:
      app: phpmyadmin
  template:
    metadata:
      labels:
        app: phpmyadmin
    spec:
      containers:
      - name: phpmyadmin
        image: phpmyadmin
        ports:
        - containerPort: 3000
        env:
        - name: PMA_HOST
          valueFrom:
            configMapKeyRef:
              name: mysql-configmap
              key: database_url
        - name: PMA_PORT
          value: "3306"
        - name: PMA_USER
          valueFrom:
            secretKeyRef:
              name: mysql-secret
              key: mysql-user-username
        - name: PMA_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-secret
              key: mysql-user-password
---
apiVersion: v1
kind: Service
metadata:
  name: phpmyadmin-service
spec:
  selector:
    app: phpmyadmin
  ports:
    - protocol: TCP
      port: 8080
      targetPort: 3000

ingress-service.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-service
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  defaultBackend:
    service:
      name: phpmyadmin-service
      port:
        number: 8080
  rules:
  - host: test.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: phpmyadmin-service
            port:
              number: 8080

当我执行microk8s kubectl get ingress ingress-service时，输出为：

NAME              CLASS    HOSTS      ADDRESS     PORTS   AGE
ingress-service   public   test.com   127.0.0.1   80      45s

当我尝试访问 test.com 时，出现 502 错误。

我的 kubectl 版本：

Client Version: v1.22.2-3+9ad9ee77396805
Server Version: v1.22.2-3+9ad9ee77396805

我的microk8s的客户端和服务器版本：

Client:
  Version:  v1.5.2
  Revision: 36cc874494a56a253cd181a1a685b44b58a2e34a
  Go version: go1.15.15

Server:
  Version:  v1.5.2
  Revision: 36cc874494a56a253cd181a1a685b44b58a2e34a
  UUID: b2bf55ad-6942-4824-99c8-c56e1dee5949

至于我的microk8s自己的版本，我按照here的安装说明，所以应该是1.21/stable。 （网上查不到具体的版本，有知道的请告诉我）

mysql.yaml日志：

2021-10-14 07:05:38+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.26-1debian10 started.
2021-10-14 07:05:38+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2021-10-14 07:05:38+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.26-1debian10 started.
2021-10-14 07:05:38+00:00 [Note] [Entrypoint]: Initializing database files
2021-10-14T07:05:38.960693Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.26) initializing of server in progress as process 41
2021-10-14T07:05:38.967970Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-10-14T07:05:39.531763Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-10-14T07:05:40.591862Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1 is enabled for channel mysql_main
2021-10-14T07:05:40.592247Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1.1 is enabled for channel mysql_main
2021-10-14T07:05:40.670594Z 6 [Warning] [MY-010453] [Server] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
2021-10-14 07:05:45+00:00 [Note] [Entrypoint]: Database files initialized
2021-10-14 07:05:45+00:00 [Note] [Entrypoint]: Starting temporary server
2021-10-14T07:05:45.362827Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.26) starting as process 90
2021-10-14T07:05:45.486702Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-10-14T07:05:45.845971Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-10-14T07:05:46.022043Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1 is enabled for channel mysql_main
2021-10-14T07:05:46.022189Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1.1 is enabled for channel mysql_main
2021-10-14T07:05:46.023446Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2021-10-14T07:05:46.023728Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2021-10-14T07:05:46.026088Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2021-10-14T07:05:46.044967Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: /var/run/mysqld/mysqlx.sock
2021-10-14T07:05:46.045036Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.26'  socket: '/var/run/mysqld/mysqld.sock'  port: 0  MySQL Community Server - GPL.
2021-10-14 07:05:46+00:00 [Note] [Entrypoint]: Temporary server started.
Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/leap-seconds.list' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone1970.tab' as time zone. Skipping it.
2021-10-14 07:05:48+00:00 [Note] [Entrypoint]: Creating database testing-database
2021-10-14 07:05:48+00:00 [Note] [Entrypoint]: Creating user testinguser
2021-10-14 07:05:48+00:00 [Note] [Entrypoint]: Giving user testinguser access to schema testing-database

2021-10-14 07:05:48+00:00 [Note] [Entrypoint]: Stopping temporary server
2021-10-14T07:05:48.422053Z 13 [System] [MY-013172] [Server] Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.26).
2021-10-14T07:05:50.543822Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.26)  MySQL Community Server - GPL.
2021-10-14 07:05:51+00:00 [Note] [Entrypoint]: Temporary server stopped

2021-10-14 07:05:51+00:00 [Note] [Entrypoint]: MySQL init process done. Ready for start up.

2021-10-14T07:05:51.711889Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.26) starting as process 1
2021-10-14T07:05:51.725302Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-10-14T07:05:51.959356Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-10-14T07:05:52.162432Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1 is enabled for channel mysql_main
2021-10-14T07:05:52.162568Z 0 [Warning] [MY-013746] [Server] A deprecated TLS version TLSv1.1 is enabled for channel mysql_main
2021-10-14T07:05:52.163400Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2021-10-14T07:05:52.163556Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2021-10-14T07:05:52.165840Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2021-10-14T07:05:52.181516Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2021-10-14T07:05:52.181562Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.26'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server - GPL.

phpmyadmin.yaml日志：

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.1.114.139. Set the 'ServerName' directive globally to suppress this message
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.1.114.139. Set the 'ServerName' directive globally to suppress this message
[Thu Oct 14 03:57:32.653011 2021] [mpm_prefork:notice] [pid 1] AH00163: Apache/2.4.51 (Debian) PHP/7.4.24 configured -- resuming normal operations
[Thu Oct 14 03:57:32.653240 2021] [core:notice] [pid 1] AH00094: Command line: 'apache2 -D FOREGROUND'

这也是我在describe nodes 上的Allocatable 命令：

Allocatable:
  cpu:                4
  ephemeral-storage:  113289380Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             5904508Ki
  pods:               110

还有Allocated resources:

Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits
  --------           --------    ------
  cpu                550m (13%)  200m (5%)
  memory             270Mi (4%)  370Mi (6%)
  ephemeral-storage  0 (0%)      0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)

有什么帮助吗？提前致谢。

【问题讨论】：

能否请您提供您的日志？

抱歉，忘记添加了，查看最新更新@kkopczak

抱歉很久没有回复。看来你资源不足。我找到了this similar issue。你能运行kubectl describe nodes 命令并检查可用资源吗？

您能否具体说明您希望看到kubectl describe nodes 的回报的哪一部分？ @kkopczak

Allocated resources: 和 Allocatable:

【参考方案1】：

原来这是我捏造的错误，我将 phpmyadmin 的容器端口指定为 3000，而默认图像端口打开为 80。将 containerPort 和 phpmyadmin-service 的 targetPort 更改为80，它打开了phpmyadmin的页面。

非常抱歉 kkopczak 和 AndD 大惊小怪，也非常感谢您提供帮助！ :)