Podman

# Run container (identical to Docker)
podman run -d --name webserver -p 8080:80 nginx

# List containers
podman ps -a

# Stop and remove
podman stop webserver
podman rm webserver

# Execute command
podman exec -it webserver /bin/sh

# View logs
podman logs -f webserver

# Pull image
podman pull docker.io/library/nginx:latest

# List images
podman images

# Build image
podman build -t myapp:latest .

# Push to registry
podman push myapp:latest registry.example.com/myapp:latest

# Remove image
podman rmi nginx:latest

# Check user namespace support
cat /proc/sys/user/max_user_namespaces

# Enable if needed (as root)
echo "user.max_user_namespaces=28633" | sudo tee /etc/sysctl.d/userns.conf
sudo sysctl -p /etc/sysctl.d/userns.conf

# Configure subuid/subgid for user
sudo usermod --add-subuids 100000-165535 --add-subgids 100000-165535 $USER

# Verify
podman unshare cat /proc/self/uid_map

# Run as regular user (no sudo)
podman run -d --name myapp -p 8080:80 nginx

# Check user namespace mapping
podman unshare id

# Verify non-root
podman top myapp user

# Rootless cannot bind to ports < 1024 by default
# Use ports >= 1024
podman run -d -p 8080:80 nginx

# Or enable unprivileged ports (as root)
echo "net.ipv4.ip_unprivileged_port_start=80" | sudo tee /etc/sysctl.d/ports.conf
sudo sysctl -p /etc/sysctl.d/ports.conf

# Create pod
podman pod create --name mypod -p 8080:80 -p 5432:5432

# Add containers to pod
podman run -d --pod mypod --name web nginx
podman run -d --pod mypod --name db postgres:15

# List pods
podman pod ps

# Containers share network namespace
podman exec web curl localhost:5432

# Start/stop pod (affects all containers)
podman pod start mypod
podman pod stop mypod

# Remove pod and containers
podman pod rm -f mypod

# View pod details
podman pod inspect mypod

# Generate Kubernetes YAML from pod
podman generate kube mypod > mypod.yaml

# Generate unit file for container
podman generate systemd --new --name myapp > ~/.config/systemd/user/container-myapp.service

# For pod
podman generate systemd --new --name mypod --files

# Reload systemd
systemctl --user daemon-reload

# Enable and start
systemctl --user enable --now container-myapp.service

# ~/.config/containers/systemd/webapp.container
[Container]
Image=docker.io/library/nginx:latest
PublishPort=8080:80
Volume=webapp-data:/usr/share/nginx/html

[Service]
Restart=always

[Install]
WantedBy=default.target

# Reload to generate service
systemctl --user daemon-reload

# Start the service
systemctl --user start webapp

# Install podman-compose
pip install podman-compose

# Run compose file
podman-compose up -d

# Or use Docker Compose with Podman socket
systemctl --user enable --now podman.socket
export DOCKER_HOST=unix:///run/user/$UID/podman/podman.sock
docker-compose up -d

# Play Kubernetes YAML
podman kube play deployment.yaml

# Stop and remove
podman kube down deployment.yaml

# Create network
podman network create mynetwork

# Run on network
podman run -d --network mynetwork --name app myapp

# Connect container to network
podman network connect mynetwork existing-container

# List networks
podman network ls

# Inspect network
podman network inspect mynetwork

# Containers on same network can resolve by name
podman run -d --network mynetwork --name db postgres:15
podman run -d --network mynetwork --name app \
  -e DATABASE_HOST=db myapp

# Create volume
podman volume create mydata

# Use volume
podman run -d -v mydata:/data myapp

# List volumes
podman volume ls

# Inspect volume
podman volume inspect mydata

# Rootless volumes location
ls ~/.local/share/containers/storage/volumes/

# Bind mount with SELinux label
podman run -v ./data:/app/data:Z myapp

# Z = private label (single container)
# z = shared label (multiple containers)

# Edit registries.conf
# ~/.config/containers/registries.conf

unqualified-search-registries = ["docker.io", "quay.io"]

[[registry]]
prefix = "docker.io"
location = "docker.io"

[[registry.mirror]]
location = "mirror.gcr.io"

# Login to registry
podman login docker.io

# Login to private registry
podman login registry.example.com

# Credentials stored in
# ~/.config/containers/auth.json

# Podman uses Buildah for builds
podman build -t myapp:latest .

# Build with specific format
podman build --format docker -t myapp .

# Multi-stage build
podman build --target production -t myapp:prod .

# Create container from scratch
buildah from scratch
buildah copy working-container ./app /app
buildah config --entrypoint '["/app/main"]' working-container
buildah commit working-container myapp:minimal

git status && git diff --stat
kubectl diff -f manifest.yaml