Docker-Kubernetes 找不到 manage.py

Question

我在 Django 中构建了一个 API，并使用 docker-compose 来编排 redis 和 celery 服务。现在，我想将 API 移动到 Kubernetes 集群 (AKS)。但是，当我将它运行到集群中时，我收到错误 python can't find manage.py。我使用 Kompose 工具编写了 kubernets manifest.yaml。这是我的 Dockerfile、docker-compose.yml 和 kubernets.yaml 文件

# docker-compose.yml
version: '3'

services:
  app:
    build:
      context: .
    ports:
      - "8000:8000"        
    volumes:
      - ./app:/app
    command: >
      sh -c "python3 ./manage.py makemigrations &&
             python3 ./manage.py migrate &&
             python3 ./manage.py runserver 0.0.0.0:8000"

Dockerfile

# Dockerfile
FROM python:3.8 

ENV PYTHONUNBUFFERED 1
COPY ./requirements.txt /requirements.txt
RUN pip install -r /requirements.txt

RUN mkdir /app
COPY ./app /app
WORKDIR /app

kubernets 清单

apiVersion: v1
items:
  - apiVersion: v1
    kind: Service
    metadata:
      annotations:
        kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
        kompose.version: 1.22.0 (955b78124)
      creationTimestamp: null
      labels:
        io.kompose.service: app
      name: app
    spec:
      ports:
        - name: "8000"
          port: 8000
          targetPort: 8000
      selector:
        io.kompose.service: app
    status:
      loadBalancer: {}


  - apiVersion: apps/v1
    kind: Deployment
    metadata:
      annotations:
        kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
        kompose.version: 1.22.0 (955b78124)
      creationTimestamp: null
      labels:
        io.kompose.service: app
      name: app
    spec:
      replicas: 1
      selector:
        matchLabels:
          io.kompose.service: app
      strategy:
        type: Recreate
      template:
        metadata:
          annotations:
            kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
            kompose.version: 1.22.0 (955b78124)
          creationTimestamp: null
          labels:
            io.kompose.service: app
        spec:
          containers:
            - args:
                - sh
                - -c
                - |-
                  python manage.py makemigrations &&
                  python manage.py migrate &&
                  python manage.py runserver 0.0.0.0:8000
              image: <image pushed in a Azure Container Registry (ACR)>
              name: app
              ports:
                - containerPort: 8000
              resources: {}
              volumeMounts:
                - mountPath: /app
                  name: app-claim0
          restartPolicy: Always
          volumes:
            - name: app-claim0
              persistentVolumeClaim:
                claimName: app-claim0
    status: {}
  - apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: app-claim0
      name: app-claim0
    spec:
      accessModes:
        - ReadWriteOnce
      resources:
        requests:
          storage: 100Mi
    status: {}

日志错误

$ kubectl logs app-6fc488bf56-hb8g9 --previous
# python: can't open file 'manage.py': [Errno 2] No such file or director

Answer 1

我认为您的问题在于 kubernetes 配置的 volumes 部分。

在您的 docker-compose 配置中，您有一个卷安装

volumes:
 - ./app:/app

这对于本地开发非常有用，因为它会获取您机器上的代码副本并将其覆盖在 docker 映像上，因此您在机器上所做的更改将反映在您正在运行的 docker 容器中，从而允许runserver查看文件更改并根据需要重新加载 django 服务器。

这在 kubernetes 中不太好 - 当您在 prod 中运行时，您希望使用已嵌入到映像中的代码。由于这是当前配置的，我认为您正在创建一个 empty PersistentVolumeClaim，然后将其安装在正在运行的容器中的 /app 目录之上。由于它是空的，所以没有找到manage.py 文件。

尝试让您的 kubernetes 配置如下所示：

apiVersion: v1
items:
  - apiVersion: v1
    kind: Service
    metadata:
      annotations:
        kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
        kompose.version: 1.22.0 (955b78124)
      creationTimestamp: null
      labels:
        io.kompose.service: app
      name: app
    spec:
      ports:
        - name: "8000"
          port: 8000
          targetPort: 8000
      selector:
        io.kompose.service: app
    status:
      loadBalancer: {}


  - apiVersion: apps/v1
    kind: Deployment
    metadata:
      annotations:
        kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
        kompose.version: 1.22.0 (955b78124)
      creationTimestamp: null
      labels:
        io.kompose.service: app
      name: app
    spec:
      replicas: 1
      selector:
        matchLabels:
          io.kompose.service: app
      strategy:
        type: Recreate
      template:
        metadata:
          annotations:
            kompose.cmd: kompose convert -f docker-compose.yml -o kb_manifests.yaml
            kompose.version: 1.22.0 (955b78124)
          creationTimestamp: null
          labels:
            io.kompose.service: app
        spec:
          containers:
            - args:
                - sh
                - -c
                - |-
                  python manage.py makemigrations &&
                  python manage.py migrate &&
                  python manage.py runserver 0.0.0.0:8000
              image: <image pushed in a Azure Container Registry (ACR)>
              name: app
              ports:
                - containerPort: 8000
              resources: {}
          restartPolicy: Always
    status: {}

这应该与您所拥有的相同，减去对卷的任何引用。

如果这行得通，那么您就可以参加比赛了。一旦它启动并运行，请查看Django deployment guide 关于您应该配置的其他一些设置 - 即，看看 gunicorn； runserver 不是您进行生产部署的最佳途径。