How to use existing directory ~/.ssh in docker-compose named volumes?

Question

I want to map my ~/.ssh to docker container .ssh . I have docker compose as

version: '3'

volumes:
  ssh-data:
    driver: local
    driver_opts:
      type: none
      device: ~/.ssh/
      o: bind

services:
  mysql:
    container_name: mysql
    image: chagridsada/galera-mariadb
    ports:
      - "3306:3306"
    volumes:
      - "ssh-data:/app/.ssh/"
    environment:
      CLUSTER_NAME: galera-db-cluster
      CLUSTER_JOIN:
      MYSQL_ROOT_PASSWORD: dev
      XTRABACKUP_PASSWORD: dev

but when I try to run the container, it gives error.

$ docker-compose up -d

Creating network "training_default" with the default driver
Creating volume "training_ssh-data" with local driver
Creating mysql ... error

ERROR: for mysql  Cannot start service mysql: error while mounting volume '/var/lib/docker/volumes/training_ssh-data/_data': failed to mount local volume: mount ~/.ssh/:/var/lib/docker/volumes/training_ssh-data/_data, flags: 0x1000: no such file or directory

ERROR: for mysql  Cannot start service mysql: error while mounting volume '/var/lib/docker/volumes/training_ssh-data/_data': failed to mount local volume: mount ~/.ssh/:/var/lib/docker/volumes/training_ssh-data/_data, flags: 0x1000: no such file or directory
ERROR: Encountered errors while bringing up the project.

its trying to map with /var/lib/docker/volumes/training_ssh-data/_data in container, but in docker-compose.yml its mapped to /app/.ssh/ .

If I change mapping to ~/.ssh:/app/.ssh , then it will work fine, but I have to use ssh-data volume for other container too, so I have to create named volume .

Why its trying to map with /var/lib/docker/volumes/training_ssh-data/_data ?

Answer 1

I think (??) the issue is that you're using a relative ( ~/.ssh ) reference within the Docker Compose and you should should use an absolute reference

If I recall correctly, you can use environment variables within Docker Compose files and so could replace ~/.ssh with ${HOME}/.ssh on Linux.