Tukukkk

I am stuck trying to configure docker volumes to share files between my host and make able in my container to use this files. let me explain.

I have a rails docker app with puma as a web server, I want to make able to puma to view and use the ssl .key and .crt files, so for this project also I am using docker-compose in "production mode", but I do not know how to make this work.

My setup is this:

• Ubuntu 18.04 server host for production has the ssl files inside /home/ubuntu/my_app_keys, the containers are also in my host.

/home/ubuntu/docker-compose.yml

version: '3'



services:

  postgres:

    image: postgres:10.5

    environment: 

      POSTGRES_DB: my_app_production

    env_file:

      -~/production.env



  redis:

    image: redis:4.0.11



  web:

    image: my_app:latest

    command: bundle exec rails server -p 3000 -b 'ssl://127.0.0.1:3000?key=/home/ubuntu/my_app_keys/server.key&cert=/home/ubuntu/my_app_keys/server.crt' -e production

    ports:

      - '3000:3000'

    volumes:

      - /home/ubuntu/my_app_keys

    depends_on:

      - postgres

      - redis

    env_file:

      - ~/production.env

    restart: always



  sidekiq:

    image: my_app_sidekiq:latest

    command: bundle exec sidekiq -C config/sidekiq.yml

    depends_on:

      - postgres

      - redis

    env_file:

      - ~/production.env

    restart: always

so, as you can see: command: bundle exec rails server -p 3000 -b 'ssl://127.0.0.1:3000?key=/home/ubuntu/my_app_keys/server.key&cert=/home/ubuntu/my_app_keys/server.crt' is looking for ssl files in /home/ubuntu/my_app_keys, when I execute docker-compose up puma can not find the ssl files and exits with:

/usr/local/bundle/gems/puma-3.9.1/lib/puma/minissl.rb:180:in `key=': No such key file '/home/ubuntu/my_app_keys/server.key' (ArgumentError)

I think is because key=/home/ubuntu/my_app_keys/server.key&cert=/home/ubuntu/my_app_keys/server.crt are pointing in the container context but I have the cert and key in my host context

so, I include in docker compose volume in order to bind-mount the files:

volumes:

  - /home/ubuntu/my_app_keys

but without luck, same error.

In the container context my app lives in /var/www/my_app directory, so I tried to specify an absolute path (for some reason I imagined that it was because the ssl files were not in the same directory where my app lived could not be shared), so I add as compose-file docs say:

volumes:

  - /home/ubuntu/my_app_keys:/var/www/my_app

and change in compose file:

command: bundle exec rails server -p 3000 -b 'ssl://127.0.0.1:3000?key=server.key&cert=server.crt' -e

when I execute the compose up my web service exit with error:

web | Could not locate Gemfile or .bundle/ directory

only way that web service run is (but no ssl files exist):

volumes:

  - /home/ubuntu/my_app_keys

so, I do not know what to do now. any help?

When your Docker Compose YAML file says:

volumes:

  - /home/ubuntu/my_app_keys

It means, "make /home/ubuntu/my_app_keys in container space persist across restarts of the container; it will start off empty unless the Dockerfile did something special; it's not connected to any specific host content".

When you say:

volumes:

  - /home/ubuntu/my_app_keys:/var/www/my_app

It means, "totally replace the contents of /var/www/my_app in container space with the contents of /home/ubuntu/my_app_keys on the host". (The path names in host and container space don't need to be the same.)

As a bonus question, when you say:

rails server -b 'ssl://127.0.0.1:3000?...'

It means, "only listen for inbound connections on port 3000 initiated from within this Docker container; don't accept any connections from outside the container at all, whether from the same physical host, other containers, or elsewhere."