Introduction to Podman: Features, Differences from Docker, and Practical Usage Guide

Podman is an open‑source container runtime that works on most Linux platforms and offers Docker‑compatible commands while eliminating the need for a privileged daemon, allowing rootless operation.

Key differences from Docker include the absence of a central daemon, a more logical process hierarchy, and direct use of OCI runtimes such as runC or crun , which improves security and resource management.

Common commands (all prefixed with podman ) cover container lifecycle ( run , start , stop , restart , ps , inspect , logs , top , rm ), image handling ( pull , push , build , tag , rmi , save , load ), and volume management.

Installation on CentOS/RHEL can be performed with yum -y install podman . For rootless usage, additional packages such as crun , slirp4netns , and fuse‑overlayfs may be required, and configuration files ( /etc/containers/containers.conf , /etc/containers/storage.conf , /etc/containers/registries.conf ) should be adjusted accordingly.

Configuration examples show how to set up registries, storage drivers, and OCI runtimes, as well as how to map user IDs via /etc/subuid and /etc/subgid for proper permission handling in rootless containers.

Usage examples demonstrate pulling an image, running a container, inspecting it, viewing logs, exposing ports (with the net.ipv4.ip_unprivileged_port_start sysctl tweak for privileged ports), and sharing volumes between host and container, including the --userns=keep-id flag to preserve file ownership.

The article concludes with a summary that Podman simplifies container discovery, execution, building, and sharing, while offering additional features beyond Docker and supporting seamless migration via an alias ( alias docker=podman ).