github.com/containers/podman/v4@v4.9.4/README.md (about) 1 ![PODMAN logo](https://raw.githubusercontent.com/containers/common/main/logos/podman-logo-full-vert.png) 2 3 # Podman: A tool for managing OCI containers and pods 4 ![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg) 5 ![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/containers/podman) 6 [![Go Report Card](https://goreportcard.com/badge/github.com/containers/libpod)](https://goreportcard.com/report/github.com/containers/libpod) 7 8 <br/> 9 10 Podman (the POD MANager) is a tool for managing containers and images, volumes mounted into those containers, and pods made from groups of containers. 11 Podman runs containers on Linux, but can also be used on Mac and Windows systems using a Podman-managed virtual machine. 12 Podman is based on libpod, a library for container lifecycle management that is also contained in this repository. The libpod library provides APIs for managing containers, pods, container images, and volumes. 13 14 15 All releases are GPG signed. Public keys of members of the team approved to make releases are located [here](https://github.com/containers/release-keys/tree/main/podman). 16 17 * Continuous Integration: 18 * [![Build Status](https://api.cirrus-ci.com/github/containers/podman.svg)](https://cirrus-ci.com/github/containers/podman/master) 19 * [GoDoc: ![GoDoc](https://godoc.org/github.com/containers/podman/libpod?status.svg)](https://godoc.org/github.com/containers/podman/libpod) 20 * [Downloads](DOWNLOADS.md) 21 22 ## Overview and scope 23 24 At a high level, the scope of Podman and libpod is the following: 25 26 * Support for multiple container image formats, including OCI and Docker images. 27 * Full management of those images, including pulling from various sources (including trust and verification), creating (built via Containerfile or Dockerfile or committed from a container), and pushing to registries and other storage backends. 28 * Full management of container lifecycle, including creation (both from an image and from an exploded root filesystem), running, checkpointing and restoring (via CRIU), and removal. 29 * Full management of container networking, using Netavark. 30 * Support for pods, groups of containers that share resources and are managed together. 31 * Support for running containers and pods without root or other elevated privileges. 32 * Resource isolation of containers and pods. 33 * Support for a Docker-compatible CLI interface, which can both run containers locally and on remote systems. 34 * No manager daemon, for improved security and lower resource utilization at idle. 35 * Support for a REST API providing both a Docker-compatible interface and an improved interface exposing advanced Podman functionality. 36 * Support for running on Windows and Mac via virtual machines run by `podman machine`. 37 38 ## Roadmap 39 40 1. A fully-featured GUI frontend for `podman machine` 41 1. Further improvements to `podman generate kube` and `podman play kube` 42 1. Improvements to Pods, including the addition of pod-level resource limits 43 44 ## Communications 45 46 If you think you've identified a security issue in the project, please *DO NOT* report the issue publicly via the GitHub issue tracker, mailing list, or IRC. 47 Instead, send an email with as many details as possible to `security@lists.podman.io`. This is a private mailing list for the core maintainers. 48 49 For general questions and discussion, please use Podman's 50 [channels](https://podman.io/community/#slack-irc-matrix-and-discord). 51 52 For discussions around issues/bugs and features, you can use the GitHub 53 [issues](https://github.com/containers/podman/issues) 54 and 55 [PRs](https://github.com/containers/podman/pulls) 56 tracking system. 57 58 There is also a [mailing list](https://lists.podman.io/archives/) at `lists.podman.io`. 59 You can subscribe by sending a message to `podman-join@lists.podman.io` with the subject `subscribe`. 60 61 ## Rootless 62 Podman can be easily run as a normal user, without requiring a setuid binary. 63 When run without root, Podman containers use user namespaces to set root in the container to the user running Podman. 64 Rootless Podman runs locked-down containers with no privileges that the user running the container does not have. 65 Some of these restrictions can be lifted (via `--privileged`, for example), but rootless containers will never have more privileges than the user that launched them. 66 If you run Podman as your user and mount in `/etc/passwd` from the host, you still won't be able to change it, since your user doesn't have permission to do so. 67 68 Almost all normal Podman functionality is available, though there are some [shortcomings](https://github.com/containers/podman/blob/main/rootless.md). 69 Any recent Podman release should be able to run rootless without any additional configuration, though your operating system may require some additional configuration detailed in the [install guide](https://podman.io/getting-started/installation). 70 71 A little configuration by an administrator is required before rootless Podman can be used, the necessary setup is documented [here](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md). 72 73 ## Podman Desktop 74 75 [Podman Desktop](https://podman-desktop.io/) is a new project under the container organization built to help the developers working with containers from their local environment with a desktop UI. Podman Desktop is still in its early days, but already provides capabilities to list your images, interact with containers (access logs, get a terminal), connect to registries (pull private images, push your images) and configure podman settings (proxies). The project develops on [Github](https://github.com/containers/podman-desktop) and contributors are welcome. 76 77 ## Out of scope 78 79 * Specialized signing and pushing of images to various storage backends. 80 See [Skopeo](https://github.com/containers/skopeo/) for those tasks. 81 * Support for the Kubernetes CRI interface for container management. 82 The [CRI-O](https://github.com/cri-o/cri-o) daemon specializes in that. 83 84 ## OCI Projects Plans 85 86 Podman uses OCI projects and best of breed libraries for different aspects: 87 - Runtime: We use the [OCI runtime tools](https://github.com/opencontainers/runtime-tools) to generate OCI runtime configurations that can be used with any OCI-compliant runtime, like [crun](https://github.com/containers/crun/) and [runc](https://github.com/opencontainers/runc/). 88 - Images: Image management uses the [containers/image](https://github.com/containers/image) library. 89 - Storage: Container and image storage is managed by [containers/storage](https://github.com/containers/storage). 90 - Networking: Networking support through use of [Netavark](https://github.com/containers/netavark) and [Aardvark](https://github.com/containers/aardvark-dns). Rootless networking is handled via [slirp4netns](https://github.com/rootless-containers/slirp4netns). 91 - Builds: Builds are supported via [Buildah](https://github.com/containers/buildah). 92 - Conmon: [Conmon](https://github.com/containers/conmon) is a tool for monitoring OCI runtimes, used by both Podman and CRI-O. 93 - Seccomp: A unified [Seccomp](https://github.com/containers/common/blob/main/pkg/seccomp/seccomp.json) policy for Podman, Buildah, and CRI-O. 94 95 ## Podman Information for Developers 96 97 For blogs, release announcements and more, please checkout the [podman.io](https://podman.io) website! 98 99 **[Installation notes](install.md)** 100 Information on how to install Podman in your environment. 101 102 **[OCI Hooks Support](https://github.com/containers/common/blob/main/pkg/hooks/README.md)** 103 Information on how Podman configures [OCI Hooks][spec-hooks] to run when launching a container. 104 105 **[Podman API](https://docs.podman.io/en/latest/_static/api.html)** 106 Documentation on the Podman REST API. 107 108 **[Podman Commands](https://podman.readthedocs.io/en/latest/Commands.html)** 109 A list of the Podman commands with links to their man pages and in many cases videos 110 showing the commands in use. 111 112 **[Podman Troubleshooting Guide](troubleshooting.md)** 113 A list of common issues and solutions for Podman. 114 115 **[Podman Usage Transfer](transfer.md)** 116 Useful information for ops and dev transfer as it relates to infrastructure that utilizes Podman. This page 117 includes tables showing Docker commands and their Podman equivalent commands. 118 119 **[Tutorials](docs/tutorials)** 120 Tutorials on using Podman. 121 122 **[Remote Client](https://github.com/containers/podman/blob/main/docs/tutorials/remote_client.md)** 123 A brief how-to on using the Podman remote client. 124 125 **[Basic Setup and Use of Podman in a Rootless environment](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md)** 126 A tutorial showing the setup and configuration necessary to run Rootless Podman. 127 128 **[Release Notes](RELEASE_NOTES.md)** 129 Release notes for recent Podman versions. 130 131 **[Contributing](CONTRIBUTING.md)** 132 Information about contributing to this project. 133 134 [spec-hooks]: https://github.com/opencontainers/runtime-spec/blob/v1.0.2/config.md#posix-platform-hooks 135 136 ## Buildah and Podman relationship 137 138 Buildah and Podman are two complementary open-source projects that are 139 available on most Linux platforms and both projects reside at 140 [GitHub.com](https://github.com) with Buildah 141 [here](https://github.com/containers/buildah) and Podman 142 [here](https://github.com/containers/podman). Both, Buildah and Podman are 143 command line tools that work on Open Container Initiative (OCI) images and 144 containers. The two projects differentiate in their specialization. 145 146 Buildah specializes in building OCI images. Buildah's commands replicate all 147 of the commands that are found in a Dockerfile. This allows building images 148 with and without Dockerfiles while not requiring any root privileges. 149 Buildah’s ultimate goal is to provide a lower-level coreutils interface to 150 build images. The flexibility of building images without Dockerfiles allows 151 for the integration of other scripting languages into the build process. 152 Buildah follows a simple fork-exec model and does not run as a daemon 153 but it is based on a comprehensive API in golang, which can be vendored 154 into other tools. 155 156 Podman specializes in all of the commands and functions that help you to maintain and modify 157 OCI images, such as pulling and tagging. It also allows you to create, run, and maintain those containers 158 created from those images. For building container images via Dockerfiles, Podman uses Buildah's 159 golang API and can be installed independently from Buildah. 160 161 A major difference between Podman and Buildah is their concept of a container. Podman 162 allows users to create "traditional containers" where the intent of these containers is 163 to be long lived. While Buildah containers are really just created to allow content 164 to be added back to the container image. An easy way to think of it is the 165 `buildah run` command emulates the RUN command in a Dockerfile while the `podman run` 166 command emulates the `docker run` command in functionality. Because of this and their underlying 167 storage differences, you can not see Podman containers from within Buildah or vice versa. 168 169 In short, Buildah is an efficient way to create OCI images while Podman allows 170 you to manage and maintain those images and containers in a production environment using 171 familiar container cli commands. For more details, see the 172 [Container Tools Guide](https://github.com/containers/buildah/tree/main/docs/containertools). 173 174 ## Podman Hello 175 ``` 176 $ podman run quay.io/podman/hello 177 Trying to pull quay.io/podman/hello:latest... 178 Getting image source signatures 179 Copying blob a6b3126f3807 done 180 Copying config 25c667d086 done 181 Writing manifest to image destination 182 Storing signatures 183 !... Hello Podman World ...! 184 185 .--"--. 186 / - - \ 187 / (O) (O) \ 188 ~~~| -=(,Y,)=- | 189 .---. /` \ |~~ 190 ~/ o o \~~~~.----. ~~ 191 | =(X)= |~ / (O (O) \ 192 ~~~~~~~ ~| =(Y_)=- | 193 ~~~~ ~~~| U |~~ 194 195 Project: https://github.com/containers/podman 196 Website: https://podman.io 197 Documents: https://docs.podman.io 198 Twitter: @Podman_io 199 ``` 200 201 ## Podman Former API (Varlink) 202 Podman formerly offered a Varlink-based API for remote management of containers. However, this API 203 was replaced by the REST API. Varlink support has been removed as of the 3.0 release. 204 For more details, you can see [this blog](https://podman.io/blogs/2020/01/17/podman-new-api.html).