无法让 Django 在 k8s 中与 Postgres 对话

Question

我在 minikube 中部署了一个简单的 Django 应用程序。它有两个容器，一个用于 Django 应用程序，一个用于 postgres 数据库。它与 docker-compose 一起工作，但无法使其在 minikube k8s 集群中工作。当我打开容器的终端并 ping 服务时，它没有成功。我没有找到导致此通信错误的原因。

这是一个基本的应用程序，只有一个用于登录或注册的登录页面。登录后，您可以创建一些笔记。部署到 minikube 后，我可以访问 127.0.0.1:8000，但是当我输入信息注册时，出现以下错误。显然，它不能在数据库中存储数据。

Django 项目 settings.py 中的 DATABASES 部分：

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.postgresql_psycopg2',
    'NAME': 'postgres',
    'USER': 'postgres',
    'PASSWORD': 'postgres',
    'HOST': 'db',
    'PORT': '5432',
}
}

用于构建应用映像的 Dockerfile：

FROM python:2.7

WORKDIR /notejam

COPY ./ ./

RUN pip install -r requirements.txt

EXPOSE 8000

CMD python manage.py runserver 0.0.0.0:8000

部署文件：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: notejam-deployment
  labels: 
    app: notejam-app
spec:
  selector:
    matchLabels:
      app: notejam-app
  template:
    metadata:
      labels:
        app: notejam-app
    spec:
      volumes:
        - name: postgres-pvc
          persistentVolumeClaim:
            claimName: postgres-pvc
      containers:
      - name: notejam
        image: notejam_k8s
        imagePullPolicy: Never
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        ports:
        - containerPort: 8000
      - name: postgres-db
        image: postgres
        imagePullPolicy: Never
        ports:
        - containerPort: 5432
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        env:
        - name: POSTGRES_USERNAME
          valueFrom:
            configMapKeyRef:
              name: postgres-configmap
              key: postgres-username
        - name: POSTGRES_PASSWORD
          valueFrom:
            secretKeyRef:
              name: postgres-secret
              key: postgres-password
        - name: POSTGRES_DB
          valueFrom:
            configMapKeyRef:
              name: postgres-configmap
              key: postgres-db
        volumeMounts:
          - mountPath: /notejam-db
            name: postgres-pvc
---
apiVersion: v1
kind: Service
metadata:
  name: db
spec:
  selector:
    app: notejam-app
  ports:
  - port: 5432
    targetPort: 5432
---
apiVersion: v1
kind: Service
metadata:
  name: notejam-external-service
spec:
  selector:
    app: notejam-app
  type: LoadBalancer
  ports:
  - protocol: TCP 
    port: 8000
    targetPort: 8000

错误：

OperationalError at /signup/

could not connect to server: Connection timed out
    Is the server running on host "db" (10.96.150.207) and accepting
    TCP/IP connections on port 5432?

Request Method:     POST
Request URL:    http://127.0.0.1:8000/signup/
Django Version:     1.6.5
Exception Type:     OperationalError
Exception Value:    

could not connect to server: Connection timed out
    Is the server running on host "db" (10.96.150.207) and accepting
    TCP/IP connections on port 5432?

Exception Location:     /usr/local/lib/python2.7/site-packages/psycopg2/__init__.py in connect, line 127
Python Executable:  /usr/local/bin/python
Python Version:     2.7.18
Python Path:    

['/notejam',
'/usr/local/lib/python27.zip',
'/usr/local/lib/python2.7',
'/usr/local/lib/python2.7/plat-linux2',
'/usr/local/lib/python2.7/lib-tk',
'/usr/local/lib/python2.7/lib-old',
'/usr/local/lib/python2.7/lib-dynload',
'/usr/local/lib/python2.7/site-packages']

Server time:    Thu, 26 Aug 2021 00:40:58 +0300

Answer 1

您正在尝试运行 postgres 作为同一 pod 中的辅助容器。应该是自己的部署和服务。多容器 pods 不像 docker compose :)

无法让 Django 在 k8s 中与 Postgres 对话

Couldn't Make Django Talk with Postgres in k8s

deployment

django

docker

kubernetes

docker-compose