[DOCKER] What to do if error while creating mount source path'/ host_mnt / Users / ~': mkdir / host_mnt / Users / ~: file exists when the container starts

phenomenon

Stop the container (for MySQL) that sets volumes → Start it

$ docker-compose up -d
Creating volume "sample_db-store" with default driver
Creating hoge_db_1 ... error

ERROR: for sample_db_1  Cannot start service db: error while creating mount source path '/host_mnt/Users/~/docker/mysql/sql': mkdir /host_mnt/Users/~/docker/mysql/sql: file exists
ERROR: Encountered errors while bringing up the project.

An error message stating "The host directory cannot be mounted" is displayed and the container cannot be started.

Operating environment

Solutions

If you are using Docker Desktop for Windows

Docker Desktop for Windows → [Settings] → [Shared Drives] → [Reset Credentials] → Reauthentication (check the corresponding path)

[reference] https://www.nuits.jp/entry/docker-for-windows-mkdir-file-exists

If you are using Docker Desktop for Mac

Docker Desktop for Mac → [preferences...] →[Resources] →[File Sharing]

After deleting ** / Users **, [apply & Restart]

Then add ** / Users ** and [apply & Restart]

What I tried before solving

Operating background

With docker-compose, I was building a MySQL container as follows.

docker-compose.yml

version: '3'
services:
  db:
    image: mysql:8.0
    volumes:
      - db-store:/var/lib/mysql
      - ./logs:/var/log/mysql
      - ./docker/mysql/my.cnf:/etc/mysql/conf.d/my.cnf
      - ./docker/mysql/sql:/docker-entrypoint-initdb.d
    environment:
      - MYSQL_DATABASE=${DB_NAME}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASS}
      - MYSQL_ROOT_PASSWORD=${DB_PASS}
      - TZ=${TZ}
    ports:
      - ${DB_PORT}:3306
volumes: db-store

In volumes, in addition to those related to data and log

docker-compose.yml

 - ./docker/mysql/sql:/docker-entrypoint-initdb.d

Is defined.

In the image for MySQL, when mounting to /docker-entrypoint-initdb.d, the .sql, .sh file existing in the specified host side directory is read and executed when the container is started for the first time. .. https://hub.docker.com/_/mysql/

Therefore, the SQL for table creation and the shell script for executing SQL were placed in the directory ./docker/mysql/sql on the host side to be mounted on the container. It works without any problem at the first startup. The SQL and shell script I put in between were running without any problems.

However, once the container was stopped with docker-compose stop, this phenomenon occurred at startup with docker-compose up.

Tried (1): Delete volume

I found information that a similar behavior could be solved by deleting the volume, so I tried deleting the container and the named volume.

$ docker-compose down --volumes

Removing sample_db_1    ... done
Removing volume sample_db-store

$ docker-compose up -d

Failure.

Tried (2): Update the authentication information of the shared folder of Docker Desktop for Mac (this solution)

Similar Docker Daemon error

docker: Error response from daemon: error while creating mount source path '/host_mnt/c/tmp': mkdir /host_mnt/c: file exists.

Was reported when using Docker Desktop for Windows. However, I couldn't find any reports of similar errors in Docker Desktop for Mac.

It's no good, but the flow is a little different from Windows, but when I tried to imitate the solution of the above error with Docker Desktop for Mac, it worked.

Cause

I'm wondering if something went wrong with the Docker Desktop Volumes sharing settings and I couldn't access the directory information on the host side, but I don't know the details.

If you know the root cause, please let me know: qiitan-cry: