Use docker secrets on a docker-machine

Question

I'm having a problem trying to use docker secrets on a remote host that I created with docker-machine.

Below is my docker-compose.yml:

version: "3.5"

services:
  mysql:
    image: mysql:5.7
    container_name: mysql
    ports:
      - "3306:3306"
    environment:
      MYSQL_ROOT_PASSWORD_FILE: /run/secrets/db_root_password
    secrets:
      - db_root_password

secrets:
  db_root_password:
    file: ./db_root_password.txt

This works well locally, I can run docker-compose up and access mysql container.

docker-compose up

The root password has well be applied.

I'm now trying to run the container on the remote host that I created using docker-machine.

I first created the machine using docker-machine create (in this case, on exoscale cloud)

docker-machine create --driver exoscale  ... MyMachine

Then I tried to deploy the host using:

eval $(docker-machine env MyMachine)
docker-compose up

However, when I try to run on the remote host, I got the following error:

ERROR: for mysql  Cannot create container for service mysql: invalid mount config for type "bind": bind source path does not exist: /Users/user/path/to/db_root_password.txt

So it's still trying to load the secret with the path of the local file on my local machine. How can I use this secret on the remote host?

Thanks in advance for your help

Answer 1

It's looks like tour docker-machine can't find ./db_root_password.txt

Can you try to create the file db_root_password.txt inside the docker-machine in the same path?