Mounting /usr/local/bin/ to python:3 docker image

Question

I want to mount /usr/local/bin/ to my host machine from docker python:3. The reason I want to do this is because I want my PyCharm Community edition to be able to use my docker interpreter for my IDE.

Here is my docker compose file:

version: '3.8'
services:
  db:
    image: mysql:8.0
    cap_add:
      - SYS_NICE
    restart: always
    environment:
      - MYSQL_DATABASE=mydb
      - MYSQL_ROOT_PASSWORD=root
    ports:
      - '3306:3306'
    volumes:
      - db:/var/lib/mysql
      - ./db/init.sql:/docker-entrypoint-initdb.d/init.sql
  web:
    build: .
    command: python app/manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/code/app
      - ./python-env:/usr/local/bin/
    ports:
      - "8000:8000"
    environment:
      - DB_NAME=mydb
      - DB_USER=root
      - DB_PASSWORD=root
    depends_on:
      - db

volumes:
  db:
    driver: local

The problem is this line:

- ./python-env:/usr/local/bin/

The error is:

Error response from daemon: failed to create task for container: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: exec: "python": executable file not found in $PATH: unknown

I have tried to setup a symlink in my docker build file, to /usr/local/bin and mount that directory instead but I get no success. Anyone got any ideas on the problem?

Answer 1

The bin folder contains essential executables for the OS. When you mount your own volume python-env to the dockers user/local/bin, it is unable to find any required files in the mounted folder (python-env) and gives the error.

If your goal is to share a Python environment between the host and container, you can

1. Create a Python virtual environment on the host, and then mount this environment into the container at some other directory.
2. Update the container's PATH environment variable to include the path to the executables in the mounted virtual environment.

# Prepend "/my/custom/path" to the PATH which contains python executable
ENV PATH=/my/custom/path:$PATH

# Rest of your Docker Configs