kubernetes - 多个 K8S 容器通过代理连接到 Google Cloud SQL

Question

我想将我的 Kubernetes 集群连接到 Google Cloud SQL。

我至少有 10 个不同的已部署 pod，它们目前使用 JDBC url + 用户名/密码连接到 MySQL [部署到 k8s 的 docker 映像]。

是否可以使用 Google Cloud SQL 代理的单个实例并通过此代理将所有 pod 连接到 Cloud SQL 数据库？理想情况下，我想用代理替换容器中运行的 mysql。

我宁愿不必在每个部署中运行代理。我发现的唯一示例似乎表明代理需要在每个部署中声明。

Answer 1

我找到了解决方案。

使用下面的 yml 部署代理，并将部署公开为服务。最重要的是，让代理监听 0.0.0.0，而不是默认的 127.0.0.1。根据 Google Cloud sql 文档的所有秘密

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: mysql
spec:
  replicas: 1
  template:
    metadata:
      name: mysql
      labels:
        name: mysql
    spec:
      containers:
         - image: b.gcr.io/cloudsql-docker/gce-proxy:1.05
           name: cloudsql-proxy
           command: ["/cloud_sql_proxy", "--dir=/cloudsql",
                     "-instances=MYSQL:ZONE:DATABASE_INSTANCE=tcp:0.0.0.0:3306",
                     "-credential_file=/secrets/cloudsql/credentials.json"]
           volumeMounts:
             - name: cloudsql-oauth-credentials
               mountPath: /secrets/cloudsql
               readOnly: true
             - name: ssl-certs
               mountPath: /etc/ssl/certs
           ports:
             - containerPort: 3306
               name: mysql
      volumes:
        - name: cloudsql-oauth-credentials
          secret:
            secretName: cloudsql-oauth-credentials
        - name: ssl-certs
          hostPath:
            path: /etc/ssl/certs

该解决方案比在与客户端软件相同的部署中使用代理稍微贵一些，因为有一个额外的 TCP 连接。

不过有很多好处：

• 更简单，不需要修改现有的 K8S 部署文件
• 允许将实现切换到 MySQL Docker 容器或使用 Google Cloud SQL 代理，而无需对客户端配置进行任何修改。

Answer 2

You can create a deployment and a service to expose the cloudsql proxy to other pods like so:

apiVersion: v1
kind: Service
metadata:
  name: cloudsqlproxy
spec:
  ports:
  - port: 3306
    targetPort: database-port
  selector:
    app: cloudsqlproxy
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: cloudsqlproxy
spec:
  template:
    metadata:
      labels:
        app: cloudsqlproxy
    spec:
      volumes:
      - name: service-account-token
        secret:
          secretName: service-account-token
      containers:
      - name: cloudsql-proxy
        image: gcr.io/cloudsql-docker/gce-proxy:1.11
        imagePullPolicy: Always
        command:
        - /cloud_sql_proxy
        - -instances=<project>:<cloudsqlinstance>=tcp:0.0.0.0:3306
        - -credential_file=/secrets/cloudsql/credentials.json
        ports:
        - name: database-port
          containerPort: 3306
        volumeMounts:
        - name: service-account-token
          mountPath: /secrets/cloudsql
          readOnly: true

So within any of your pods, the database your MYSQL_HOST:MYSQL_PORT will be cloudsqlproxy:3306

For multiple databases through the same proxy, you'd have the same deployment structure for the proxy, except that you will now expose 2 ports from the pod, like so:

apiVersion: extensions/v1beta1
...
spec:
  template:
    ...
    spec:
      volumes:
      ...
      containers:
      - name: cloudsql-proxy
        ...
        ports:
        - name: database-port1
          containerPort: 3306
        - name: database-port2
          containerPort: 3307
        ...

Then you'd create 2 services to for discovery on those ports like so:

apiVersion: v1
kind: Service
metadata:
  name: cloudsqlproxy-db1
spec:
  ports:
  - port: 3306
    targetPort: database-port1
  selector:
    app: cloudsqlproxy
---
apiVersion: v1
kind: Service
metadata:
  name: cloudsqlproxy-db2
spec:
  ports:
  - port: 3306
    targetPort: database-port2
  selector:
    app: cloudsqlproxy

So, with both services set to port 3306, you can connect to each database on that port:

mysql --host=cloudsqlproxy-db1 --port=3306 ...
mysql --host=cloudsqlproxy-db2 --port=3306 ...

Reference: https://github.com/GoogleCloudPlatform/cloudsql-proxy/blob/master/Kubernetes.md

Answer 3

有了谷歌“私有 IP”，云代理现在就无关紧要了！