Why Choose Podman Over Docker? Complete Guide to Installation, Commands, and Best Practices

Podman Overview

Podman is an open‑source container runtime that works on most Linux platforms. It offers Docker‑compatible commands but runs without a daemon and can operate without root privileges.

Key Differences Between Podman and Docker

Docker requires a root‑owned daemon (dockerd); Podman does not need a daemon.

Podman can run rootless, making its architecture more secure.

Docker’s engine uses multiple daemons (dockerd → containerd → containerd‑shim → runc); Podman calls the OCI runtime (runC) directly via a “conmon” process, which is analogous to containerd‑shim.

Using Podman vs Docker

Podman’s command line mirrors Docker’s, covering container lifecycle (run, start, ps, stop, restart, attach, exec, logs, rm) and image management (search, pull, images, rmi, build, save, load, tag, push).

Common Podman Commands

podman run          # create and start a container
podman start        # start a container
podman ps           # list containers
podman stop         # stop a container
podman restart      # restart a container
podman attach       # attach to a container
podman exec         # execute a command in a container
podman logs         # view container logs
podman rm           # remove a container
podman images       # list images
podman build        # build an image from a Dockerfile
podman push         # upload an image to a registry

Installing and Configuring Podman

On CentOS/RHEL install with yum -y install podman. Adjust /etc/containers/registries.conf to set search registries, insecure registries, or mirrors. For rootless operation, install crun and set runtime = "crun" in /etc/containers/containers.conf. Install slirp4netns and fuse‑overlayfs for user namespaces and overlay storage.

Rootless User Configuration

Map UID/GID ranges in /etc/subuid and /etc/subgid, and optionally adjust net.ipv4.ip_unprivileged_port_start to allow binding privileged ports.

Volumes and File Ownership

When a container runs as root, files created inside appear owned by root on the host. Using --userns=keep-id preserves the host user’s UID/GID inside the container.

Aliases for Seamless Migration

Add alias docker=podman to .bashrc to use Docker‑style commands with Podman.