如何在Kubernetes上的Google Cloud上备份Postgres数据库? [英] How to backup a Postgres database in Kubernetes on Google Cloud?

问题描述

备份在 Google Cloud Container Engine 上运行的Postgres数据库的最佳实践是什么? ?

我的想法是努力将备份存储在 Google Cloud Storage 中，但是我不确定如何将磁盘/Pod连接到存储桶.

我正在使用以下配置在Kubernetes集群中运行Postgres:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: postgres-deployment
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - image: postgres:9.6.2-alpine
          imagePullPolicy: IfNotPresent
          env:
            - name: PGDATA
              value: /var/lib/postgresql/data
            - name: POSTGRES_DB
              value: my-database-name
            - name: POSTGRES_PASSWORD
              value: my-password
            - name: POSTGRES_USER
              value: my-database-user
          name: postgres-container
          ports:
            - containerPort: 5432
          volumeMounts:
            - mountPath: /var/lib/postgresql
              name: my-postgres-volume
      volumes:
        - gcePersistentDisk:
            fsType: ext4
            pdName: my-postgres-disk
          name: my-postgres-volume

我试图创建工作来运行备份:

apiVersion: batch/v1
kind: Job
metadata:
  name: postgres-dump-job
spec:
  template:
    metadata:
      labels:
        app: postgres-dump
    spec:
      containers:
        - command:
            - pg_dump
            - my-database-name
          # `env` value matches `env` from previous configuration.
          image: postgres:9.6.2-alpine
          imagePullPolicy: IfNotPresent
          name: my-postgres-dump-container
          volumeMounts:
            - mountPath: /var/lib/postgresql
              name: my-postgres-volume
              readOnly: true
      restartPolicy: Never
      volumes:
        - gcePersistentDisk:
            fsType: ext4
            pdName: my-postgres-disk
          name: my-postgres-volume

(据我了解)，这应该运行 pg_dump 命令，并将备份数据输出到stdout(应该显示在kubectl logs中).

顺便说一句，当我检查Pod(使用kubectl get pods)时，它表明Pod从未脱离待处理"状态，这是由于没有足够的资源来启动作业而导致的.

/p>

以Job身份运行此过程是否正确? 如何将作业连接到Google Cloud Storage? 还是我应该做一些完全不同的事情?

我猜测由于性能下降，在数据库容器(带有kubectl exec)中运行pg_dump是不明智的，但是在开发/登台服务器中可以这样做吗?

解决方案

就像@Marco Lamina所说的那样，您可以像

那样在postgres pod上运行pg_dump.

DUMP
// pod-name         name of the postgres pod
// postgres-user    database user that is able to access the database
// database-name    name of the database
kubectl exec [pod-name] -- bash -c "pg_dump -U [postgres-user] [database-name]" > database.sql


RESTORE
// pod-name         name of the postgres pod
// postgres-user    database user that is able to access the database
// database-name    name of the database
cat database.sql | kubectl exec -i [pod-name] -- psql -U [postgres-user] -d [database-name]

您可以拥有一个运行此命令的作业窗格，并将其导出到文件存储系统(例如AWS s3).

What is the best practice for backing up a Postgres database running on Google Cloud Container Engine?

My thought is working towards storing the backups in Google Cloud Storage, but I am unsure of how to connect the Disk/Pod to a Storage Bucket.

I am running Postgres in a Kubernetes cluster using the following configuration:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: postgres-deployment
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - image: postgres:9.6.2-alpine
          imagePullPolicy: IfNotPresent
          env:
            - name: PGDATA
              value: /var/lib/postgresql/data
            - name: POSTGRES_DB
              value: my-database-name
            - name: POSTGRES_PASSWORD
              value: my-password
            - name: POSTGRES_USER
              value: my-database-user
          name: postgres-container
          ports:
            - containerPort: 5432
          volumeMounts:
            - mountPath: /var/lib/postgresql
              name: my-postgres-volume
      volumes:
        - gcePersistentDisk:
            fsType: ext4
            pdName: my-postgres-disk
          name: my-postgres-volume

I have attempted to create a Job to run a backup:

apiVersion: batch/v1
kind: Job
metadata:
  name: postgres-dump-job
spec:
  template:
    metadata:
      labels:
        app: postgres-dump
    spec:
      containers:
        - command:
            - pg_dump
            - my-database-name
          # `env` value matches `env` from previous configuration.
          image: postgres:9.6.2-alpine
          imagePullPolicy: IfNotPresent
          name: my-postgres-dump-container
          volumeMounts:
            - mountPath: /var/lib/postgresql
              name: my-postgres-volume
              readOnly: true
      restartPolicy: Never
      volumes:
        - gcePersistentDisk:
            fsType: ext4
            pdName: my-postgres-disk
          name: my-postgres-volume

(As far as I understand) this should run the pg_dump command and output the backup data to stdout (which should appear in the kubectl logs).

As an aside, when I inspect the Pods (with kubectl get pods), it shows the Pod never gets out of the "Pending" state, which I gather is due to there not being enough resources to start the Job.

Is it correct to run this process as a Job? How do I connect the Job to Google Cloud Storage? Or should I be doing something completely different?

I'm guessing it would be unwise to run pg_dump in the database Container (with kubectl exec) due to a performance hit, but maybe this is ok in a dev/staging server?

解决方案

As @Marco Lamina said you can run pg_dump on postgres pod like

DUMP
// pod-name         name of the postgres pod
// postgres-user    database user that is able to access the database
// database-name    name of the database
kubectl exec [pod-name] -- bash -c "pg_dump -U [postgres-user] [database-name]" > database.sql


RESTORE
// pod-name         name of the postgres pod
// postgres-user    database user that is able to access the database
// database-name    name of the database
cat database.sql | kubectl exec -i [pod-name] -- psql -U [postgres-user] -d [database-name]

You can have a job pod that does run this command and exports this to a file storage system such as AWS s3.

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