docker - 如何使用EmptyDir在kubernetes上安装卷

Question

我试图用我的kompose文件创建一个部署，但是每当尝试尝试时:

kompose convert -f docker-compose.yaml

我得到错误:

Volume mount on the host "[file directory]" isn't supported - ignoring path on the host

我已经尝试了几种不同的解决方案来解决这个问题，首先尝试将hostPath添加到我的kompose convert中，以及使用持久卷，但是这两种方法都不起作用。

我的kompose文件看起来像这样:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    kompose.cmd: kompose convert -f docker-compose.yaml --volumes emptyDir
    kompose.version: 1.7.0 (HEAD)
  creationTimestamp: null
  labels:
    io.kompose.service: es01
  name: es01
spec:
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: es01
    spec:
      containers:
      - env:
        - name: COMPOSE_CONVERT_WINDOWS_PATHS
          value: "1"
        - name: COMPOSE_PROJECT_NAME
          value: elastic_search_container
        - name: ES_JAVA_OPTS
          value: -Xms7g -Xmx7g
        - name: discovery.type
          value: single-node
        - name: node.name
          value: es01
        image: docker.elastic.co/elasticsearch/elasticsearch:7.2.1
        name: es01
        ports:
        - containerPort: 9200
        resources: {}
        volumeMounts:
        - mountPath: /usr/share/elasticsearch/data
          name: es01-empty0
      restartPolicy: Always
      volumes:
      - emptyDir: {}
        name: es01-empty0
status: {}

我正在使用kompose版本1.7.0

我的Docker Compose版本:

version: '3'
services:
  es01:
    image: docker.elastic.co/elasticsearch/elasticsearch:7.2.1
    container_name: es01
    environment:
      - node.name=es01
      - COMPOSE_PROJECT_NAME=elastic_search_container
      - discovery.type=single-node
      - "ES_JAVA_OPTS=-Xms7g -Xmx7g"
      - COMPOSE_CONVERT_WINDOWS_PATHS=1
    ulimits:
      nproc: 3000
      nofile: 65536
      memlock: -1
    volumes:
      - /home/centos/Sprint0Demo/Servers/elasticsearch:/usr/share/elasticsearch/data
    ports:
      - 9200:9200
    networks:
      - kafka_demo

Answer 1

您需要看一下警告您得到:

Volume mount on the host "[file directory]" isn't supported - ignoring path on the host

当docker-compose.yaml中的卷配置有直接路径时，会发生这种情况。

下面的例子:

version: '3'
services:
  web:
    build: .
    ports:
      - "5000:5000"
    volumes:
      - "./storage1:/test1"
      - "./storage2:/test2"
  redis:
    image: "redis:alpine"
volumes:
  storage1:
  storage2:

持续体积 claim

看一下此链接:Conversion matrix。
它描述了kompose如何将Docker的卷转换为Kubernetes的卷。

在不使用--volumes参数的情况下执行转换命令:
$ kompose convert -f docker-compose.yml
使用kompose 1.19输出将产生:

WARN Volume mount on the host "SOME_PATH" isn't supported - ignoring path on the host 
WARN Volume mount on the host "SOME_PATH" isn't supported - ignoring path on the host 
INFO Kubernetes file "web-service.yaml" created   
INFO Kubernetes file "redis-deployment.yaml" created 
INFO Kubernetes file "web-deployment.yaml" created 
INFO Kubernetes file "web-claim0-persistentvolumeclaim.yaml" created 
INFO Kubernetes file "web-claim1-persistentvolumeclaim.yaml" created

警告消息表示您正在明确告诉docker-compose创建具有直接路径的卷。默认情况下，kompose将Docker的卷转换为Persistent Volume Claim。

空目录

使用--volumes emptyDir参数执行转换命令:
$ kompose convert -f docker-compose.yml --volumes emptyDir
会产生效果:

WARN Volume mount on the host "SOME_PATH" isn't supported - ignoring path on the host 
WARN Volume mount on the host "SOME_PATH" isn't supported - ignoring path on the host 
INFO Kubernetes file "web-service.yaml" created   
INFO Kubernetes file "redis-deployment.yaml" created 
INFO Kubernetes file "web-deployment.yaml" created 

kompose将在web-deployment.yaml内创建emptyDir声明，而不是像默认情况下那样创建单独的PVC定义。

hostPath

使用--volumes hostPath参数执行转换命令:
$ kompose convert -f docker-compose.yml --volumes hostPath
会产生效果:

INFO Kubernetes file "web-service.yaml" created   
INFO Kubernetes file "redis-deployment.yaml" created 
INFO Kubernetes file "web-deployment.yaml" created 

如您所见，没有关于不支持的路径的警告。没有警告，因为它使用您自己提供的docker-compose.yml路径显式创建了hostPath。

看一看web-deployment.yaml卷部分:

      volumes:
      - hostPath:
          path: /LOCAL_PATH-/POD_PATH/storage1
        name: web-hostpath0
      - hostPath:
          path: /LOCAL_PATH-/POD_PATH/storage2
        name: web-hostpath1