Complete Reference with Copy-Paste Examples
Part of The Direct Path to Linux Ubuntu
— free for all students and developers.
Build once, run anywhere — Docker containers run identically on your laptop, CI/CD, staging, and production. No more 'works on my machine'.
Containers isolate processes, filesystems, and networks. Run multiple apps on one server without conflicts or security leakage.
Docker images are the deployment unit for Kubernetes, ECS, Cloud Run, and Azure Container Apps. Container knowledge is non-negotiable.
Podman is daemonless and rootless — runs without root, no background daemon, and is fully Docker-compatible. Default on RHEL/Fedora/OpenShift.
Run Docker:
# Install Docker curl -fsSL https://get.docker.com | sh sudo usermod -aG docker $USER # run without sudo # Essential commands docker run hello-world # test installation docker run -it ubuntu bash # interactive shell docker build -t myapp:1.0 . # build image docker compose up -d # start services docker ps # list containers docker images # list images # Install Podman sudo apt install podman # Ubuntu brew install podman # macOS podman machine init && podman machine start # macOS VM
