argparser/docs/docker/docker-revised.md

Docker-Specific Guide

Docker vs Podman

This project prioritizes Podman (OCI-compliant, rootless, daemonless). For Docker, convert commands:

# Podman → Docker
podman build -t name .    →  docker build -t name .
podman run -d name        →  docker run -d name

Key Differences

SELinux

Podman: Native support, use :Z or :z for volumes

podman run -v ./data:/data:Z name

Docker: Requires selinux mount option

docker run -v ./data:/data:Z name  # May not work
docker run --security-opt label=type:container_t name

Rootless

Podman: Default rootless operation

podman run -d -p 8080:8080 name  # Works as user

Docker: Requires rootless daemon setup

dockerd-rootless-setuptool.sh install

Systemd

Podman: Native integration

podman generate systemd --new name

Docker: Use third-party solutions

Docker Files

Use Dockerfile instead of Containerfile:

docker build -f assets/Dockerfile.alpine -t argparse-builder .

Docker Compose

Standard docker-compose.yml works, but note SELinux limitations:

services:
  app:
    volumes:
      - ./data:/data # No :Z support in Docker Compose

Workaround:

chcon -Rt container_file_t ./data  # Pre-label directory

Migration to Podman

1. Replace docker with podman in commands
2. Add :Z to volume mounts for SELinux
3. Use rootless by default
4. Generate systemd units with Podman

See docs/container.md for full Podman guide.