永久Docker卷

Question

I am trying to build a Apache WebDAV private cloud server.

All my files will be in /usr/John/ directory and I can mount this location for the container to use. The problem is that I will also add new files via this server, but whatever I try they stay only within the container. Is there a way to reflect the same new files also in the host directory (/usr/John/)?

I could do a recurrent job to go into this container and CP all files to the host directory but it's not a very elegant solution.

Answer 1

Use docker volumes. All your persistent data generated by the container will be saved to var/lib/docker/volumes . If you are using docker-compise, you can do something like below. Here I have 3 volumes and I am naming it tomcat-data , host-upload , tomcat-webapps . Here all the data I put in tomcat-data , /home/foo/upload and /usr/local/tomcat/webapps will be stored on the host machine inside var/lib/docker/volumes . So even if the container goes down and you bring up another container all the data in these directories will be preserved. Let me know if you have any questions.

You can also bind mount host directories directly onto docker container. Let me know if you have any questions

version: '3.2'
services:
  tomcat:
    image: "ciena/tomcat"
    volumes:
      - tomcat-data:/tomcat-data
      - host-upload:/home/foo/upload
      - tomcat-webapps:/usr/local/tomcat/webapps
    ports:
      - target: 8080
        published: 8080
        protocol: tcp
        mode: ingress
      - target: 2222
        published: 22
        protocol: tcp
        mode: ingress
    environment:
      - JAVA_MIN_HEAP=256m
      - JAVA_MAX_HEAP=512m
    deploy:
      placement:
        constraints:
          - node.role == manager
      replicas: 1
      resources:
        limits:
          memory: 1024M
          cpus: '0.5'
        reservations:
          memory: 512M
          cpus: '0.001'
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 3
        window: 60s
volumes:
  tomcat-data:
  host-upload:
  tomcat-webapps:
networks:
  default: