This guide will discuss how to install Podman on CentOS 7 / Fedora 31/30/29. Podman is a daemonless container engine for development, management, and operation OCI Containers on Linux systems. The main difference between Docker and Podman is that there are no daemons in Podman.
For Ubuntu, please check: How to install podman on Ubuntu
Podman also uses container runtimes, such as runc, but the started container is a direct descendant of the podman process. This architecture has the following advantages:
- The applied Cgroup or security constraint still controls the container: no matter what cgroup constraint you apply to the podman command, the started container will receive the same constraint directly.
- Using this model, you can take advantage of the advanced features of systemd: this can be done by putting podman into a systemd unit file and thus implementing more features.
The following toolsets can work together to support the use of Containers without the need for a running daemon.
- Buildah Facilitate the construction of OCI images
- Skopeo Used to share / find container images on Docker registry, Atomic registry, private registry, local directory and local OCI layout directory.
- Podman does not require a daemon to run containers.
Install Podman on CentOS 7 / Fedora 31/30/29
The podman package is available in Fedora and CentOS upstream repositories.
--------- CentOS -------------- $ sudo yum -y install podman ---------- Fedora -------------- $ sudo dnf install -y podman
To view the details of the installed packages, use the rpm command.
$ rpm -qi podman Name : podman Version : 0.12.1.2 Release : 2.git9551f6b.el7.centos Architecture: x86_64 Install Date: Sat 15 Jun 2019 01:43:33 PM EAT Group : Unspecified Size : 33654116 License : ASL 2.0 Signature : RSA/SHA256, Wed 13 Feb 2019 11:56:49 PM EAT, Key ID 24c6a8a7f4a80eb5 Source RPM : podman-0.12.1.2-2.git9551f6b.el7.centos.src.rpm Build Date : Wed 13 Feb 2019 08:05:29 PM EAT Build Host : x86-02.bsys.centos.org Relocations : (not relocatable) Packager : CentOS BuildSystem http://bugs.centos.org Vendor : CentOS URL : https://github.com/containers/libpod Summary : Manage Pods, Containers and Container Images Description : Manage Pods, Containers and Container Images libpod provides a library for applications looking to use the Container Pod concept popularized by Kubernetes.
After installation, you can display information about the host, the current storage status, and the build of the podman.
$ podman info host: BuildahVersion: 1.6-dev Conmon: package: podman-0.12.1.2-2.git9551f6b.el7.centos.x86_64 path: /usr/libexec/podman/conmon version: 'conmon version 1.12.0-dev, commit: b909c9e1a3e8f14d5694a118fb9c0c0325a31d4f-dirty' Distribution: distribution: '"centos"' version: "7" MemFree: 461684736 MemTotal: 3872858112 OCIRuntime: package: runc-1.0.0-59.dev.git2abd837.el7.centos.x86_64 path: /usr/bin/runc version: 'runc version spec: 1.0.0' SwapFree: 0 SwapTotal: 0 arch: amd64 cpus: 2 hostname: techwiz-app-server kernel: 3.10.0-957.10.1.el7.x86_64 os: linux rootless: false uptime: 831h 27m 5.82s (Approximately 34.62 days) insecure registries: registries:  registries: registries: - registry.access.redhat.com - docker.io - registry.fedoraproject.org - quay.io - registry.centos.org store: ContainerStore: number: 0 GraphDriverName: overlay GraphOptions: - overlay.override_kernel_check=true GraphRoot: /var/lib/containers/storage GraphStatus: Backing Filesystem: extfs Native Overlay Diff: "true" Supports d_type: "true" ImageStore: number: 0 RunRoot: /var/run/containers/storage
Try pulling the Alpine Linux image.
$ podman pull alpine Trying to pull registry.access.redhat.com/alpine:latest...Failed Trying to pull docker.io/alpine:latest...Getting image source signatures Copying blob sha256:e7c96db7181be991f19a9fb6975cdbbd73c65f4a2681348e63a141a2192a5f10 2.63 MB / 2.63 MB [========================================================] 0s Copying config sha256:055936d3920576da37aa9bc460d70c5f212028bda1c08c0879aedf03d7a66ea1 1.48 KB / 1.48 KB [========================================================] 0s Writing manifest to image destination Storing signatures 055936d3920576da37aa9bc460d70c5f212028bda1c08c0879aedf03d7a66ea1
Check the list of downloaded images.
$ podman images REPOSITORY TAG IMAGE ID CREATED SIZE docker.io/library/alpine latest 055936d39205 5 weeks ago 5.8 MB
Using Podman on CentOS 7 / Fedora 31/30/29
Now that you have installed podman on CentOS 7 and Fedora systems, the next section is how to use it. We have a guide on this:
How to run Docker containers with Podman and Libpod
Setting up Docker container registry and encrypting SSL with Podman
Podman shows much hope for the future of containerization. In fact, Red Hat has not only removed the Docker container engine from OpenShift. It also removed the Docker container engine as well
docker The command is completely from Red Hat Enterprise Linux 8. Thank you for reading through.
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