我在连接google云平台kubernetes pod和运行在aws上的外部mysql时遇到了问题。
这是我的部署文件（一些敏感部分被替换为 *** ):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: watches-v1
spec:
  replicas: 3
  selector:
    matchLabels:
      app: watches-v1
  template:
    metadata:
      labels:
        app: watches-v1
    spec:
      containers:
      - name: watches-v1
        image: silasberger/watches:1.0
        imagePullPolicy: Always
        ports:
        - containerPort: 3000
        env:
        - name: MYSQL_HOST
          value: "***.eu-west-1.rds.amazonaws.com"
        - name: MYSQL_DB
          value: "***"
        - name: MYSQL_USER
          value: "***"
        - name: MYSQL_PASS
          value: "***"
        - name: API_USER
          value: "***"
        - name: API_PASS
          value: "***"

这是dockerfile，我构建并将其推送到dockerhub作为 watches:1.0 :

FROM node:8

WORKDIR /usr/src/app

COPY package*.json ./

RUN npm install

COPY . .

EXPOSE 3000

ENV MICROSERVICE="watches"
ENV WATCHES_API_VERSION="1"

CMD [ "npm", "start" ]

以下是有效的：
使用 mysql 命令
在本地容器中运行docker映像，没有错误，一切正常
但是，只要我在kubernetes集群中应用部署，pod就无法连接到awsdb。应用程序启动时，我可以访问swagger页面，但是当我运行 kubectl logs <pod-name> 命令，我总是得到这样的错误：

Unable to connect to the database: { SequelizeConnectionError: connect ETIMEDOUT
    at Utils.Promise.tap.then.catch.err (/usr/src/app/node_modules/sequelize/lib/dialects/mysql/connection-manager.js:149:19)
    at tryCatcher (/usr/src/app/node_modules/bluebird/js/release/util.js:16:23)
    at Promise._settlePromiseFromHandler (/usr/src/app/node_modules/bluebird/js/release/promise.js:512:31)
    at Promise._settlePromise (/usr/src/app/node_modules/bluebird/js/release/promise.js:569:18)
    at Promise._settlePromise0 (/usr/src/app/node_modules/bluebird/js/release/promise.js:614:10)
    at Promise._settlePromises (/usr/src/app/node_modules/bluebird/js/release/promise.js:690:18)
    at _drainQueueStep (/usr/src/app/node_modules/bluebird/js/release/async.js:138:12)
    at _drainQueue (/usr/src/app/node_modules/bluebird/js/release/async.js:131:9)
    at Async._drainQueues (/usr/src/app/node_modules/bluebird/js/release/async.js:147:5)
    at Immediate.Async.drainQueues (/usr/src/app/node_modules/bluebird/js/release/async.js:17:14)
    at runCallback (timers.js:810:20)
    at tryOnImmediate (timers.js:768:5)
    at processImmediate [as _immediateCallback] (timers.js:745:5)
  name: 'SequelizeConnectionError',
  parent: 
   { Error: connect ETIMEDOUT
    at Connection._handleTimeoutError (/usr/src/app/node_modules/mysql2/lib/connection.js:192:13)
    at ontimeout (timers.js:498:11)
    at tryOnTimeout (timers.js:323:5)
    at Timer.listOnTimeout (timers.js:290:5)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true },
  original: 
   { Error: connect ETIMEDOUT
    at Connection._handleTimeoutError (/usr/src/app/node_modules/mysql2/lib/connection.js:192:13)
    at ontimeout (timers.js:498:11)
    at tryOnTimeout (timers.js:323:5)
    at Timer.listOnTimeout (timers.js:290:5)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true } }

它选择了正确的主机、db名称和凭据（如日志的前一部分所示，此处未显示），但显然无法连接到它。如您所见，应用程序是用node.js编写的，并使用sequelize。
到目前为止，我所做的所有研究都指向防火墙问题，因此我为该项目在谷歌云平台上设置了以下专有网络规则：

$ gcloud compute firewall-rules describe allow-all-outbound
allowed:
- IPProtocol: all
creationTimestamp: '2018-11-14T02:51:20.808-08:00'
description: Allow all inbound connections
destinationRanges:
- 0.0.0.0/0
direction: EGRESS
disabled: false
id: '7178441953737326791'
kind: compute#firewall
name: allow-mysql-outbound
network: https://www.googleapis.com/compute/v1/projects/adept-vine-222109/global/networks/default
priority: 1000
selfLink: https://www.googleapis.com/compute/v1/projects/adept-vine-222109/global/firewalls/allow-mysql-outbound

因为这并没有改变任何事情，我还尝试再次添加相同的规则 direction INGRESS ，但这也没有起作用（正如我所料）。
我对google云平台和kubernetes完全陌生，所以也许这只是一个愚蠢的错误，但我真的没有办法让它工作。