#python #docker #docker-compose

Approaches to runing a Python site under Docker (development environment).md

Approaches to runing a Python site under Docker (development environment)

1. The straightfoward way is:

   docker-compose.yml:

   version: '3'
   services:
       site:
           build: .
           command: sleep infinity
           volumes:
               - .:/site

   Dockerfile:

   FROM python:3.9-alpine3.13
   WORKDIR /site

   This way you're running under root (the files created by processes in the container gets root ownership, particularly on the host). Which is not always handy.

2. Running under the host user:

   docker-compose.yml:

   version: '3'
   services:
       site:
           build:
               context: .
               args:
                   UID: ${UID-0}
                   GID: ${GID-0}
           user: ${UID-0}:${GID-0}
           command: sleep infinity
           volumes:
               - .:/site

   Dockerfile:

   FROM python:3.9-alpine3.13
   ARG UID
   ARG GID
   RUN apk add --no-cache shadow \
       && if [ "$UID" ] && [ "$GID" ]; then \
       if ! getent group "$GID"; then \
           groupadd --gid "$GID" site; fi \
       && if ! getent passwd "$UID"; then \
           useradd --uid "$UID" --gid "$GID" site; fi; fi
   WORKDIR /site

   This way it's by default as before, but if you create an .env file (not to be added to the repository):

   UID=1000
   GID=1000
   

   Then it will create a user in the container that matches the one on the host. And you'll no longer need to occasionally chown the files.

   You might want to add --create-home to useradd.

3. And recently I was told that under macOS the bind-mounts are really slow, so the preferred setup in that case is supposedly as follows:

   docker-compose.yml:

   version: '3'
   services:
       site:
           build: .
           command: sleep infinity
           volumes:
               - .:/site
               - site-packages:/usr/local/lib/site-packages
               # node_modules and so on...
   volumes:
       site-packages:

   Dockerfile:

   FROM python:3.9-alpine3.13
   WORKDIR /site