github.com/containers/podman/v5@v5.1.0-rc1/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/main)
    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. Further improvements to `podman machine` to better support Podman Desktop and other developer usecases.
    41  1. Support for [conmon-rs](https://github.com/containers/conmon-rs), which will improve container logging.
    42  1. Support for the BuildKit API.
    43  1. Performance and stability improvements.
    44  1. Reductions to the size of the Podman binary.
    45  
    46  ## Communications
    47  
    48  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.
    49  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.
    50  
    51  For general questions and discussion, please use Podman's
    52  [channels](https://podman.io/community/#slack-irc-matrix-and-discord).
    53  
    54  For discussions around issues/bugs and features, you can use the GitHub
    55  [issues](https://github.com/containers/podman/issues)
    56  and
    57  [PRs](https://github.com/containers/podman/pulls)
    58  tracking system.
    59  
    60  There is also a [mailing list](https://lists.podman.io/archives/) at `lists.podman.io`.
    61  You can subscribe by sending a message to `podman-join@lists.podman.io` with the subject `subscribe`.
    62  
    63  ## Rootless
    64  Podman can be easily run as a normal user, without requiring a setuid binary.
    65  When run without root, Podman containers use user namespaces to set root in the container to the user running Podman.
    66  Rootless Podman runs locked-down containers with no privileges that the user running the container does not have.
    67  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.
    68  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.
    69  
    70  Almost all normal Podman functionality is available, though there are some [shortcomings](https://github.com/containers/podman/blob/main/rootless.md).
    71  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).
    72  
    73  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).
    74  
    75  ## Podman Desktop
    76  
    77  [Podman Desktop](https://podman-desktop.io/) provides a local development environment for Podman and Kubernetes on Linux, Windows, and Mac machines.
    78  It is a full-featured desktop UI frontend for Podman which uses the `podman machine` backend on non-Linux operating systems to run containers.
    79  It supports full container lifecycle management (building, pulling, and pushing images, creating and managing containers, creating and managing pods, and working with Kubernetes YAML).
    80  The project develops on [GitHub](https://github.com/containers/podman-desktop) and contributors are welcome.
    81  
    82  ## Out of scope
    83  
    84  * Specialized signing and pushing of images to various storage backends.
    85    See [Skopeo](https://github.com/containers/skopeo/) for those tasks.
    86  * Support for the Kubernetes CRI interface for container management.
    87    The [CRI-O](https://github.com/cri-o/cri-o) daemon specializes in that.
    88  
    89  ## OCI Projects Plans
    90  
    91  Podman uses OCI projects and best of breed libraries for different aspects:
    92  - 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/).
    93  - Images: Image management uses the [containers/image](https://github.com/containers/image) library.
    94  - Storage: Container and image storage is managed by [containers/storage](https://github.com/containers/storage).
    95  - 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).
    96  - Builds: Builds are supported via [Buildah](https://github.com/containers/buildah).
    97  - Conmon: [Conmon](https://github.com/containers/conmon) is a tool for monitoring OCI runtimes, used by both Podman and CRI-O.
    98  - Seccomp: A unified [Seccomp](https://github.com/containers/common/blob/main/pkg/seccomp/seccomp.json) policy for Podman, Buildah, and CRI-O.
    99  
   100  ## Podman Information for Developers
   101  
   102  For blogs, release announcements and more, please checkout the [podman.io](https://podman.io) website!
   103  
   104  **[Installation notes](install.md)**
   105  Information on how to install Podman in your environment.
   106  
   107  **[OCI Hooks Support](https://github.com/containers/common/blob/main/pkg/hooks/README.md)**
   108  Information on how Podman configures [OCI Hooks][spec-hooks] to run when launching a container.
   109  
   110  **[Podman API](https://docs.podman.io/en/latest/_static/api.html)**
   111  Documentation on the Podman REST API.
   112  
   113  **[Podman Commands](https://podman.readthedocs.io/en/latest/Commands.html)**
   114  A list of the Podman commands with links to their man pages and in many cases videos
   115  showing the commands in use.
   116  
   117  **[Podman Container Images](https://github.com/containers/image_build/blob/main/podman/README.md)**
   118  Information on the Podman Container Images found on [quay.io](https://quay.io/podman/stable).
   119  
   120  **[Podman Troubleshooting Guide](troubleshooting.md)**
   121  A list of common issues and solutions for Podman.
   122  
   123  **[Podman Usage Transfer](transfer.md)**
   124  Useful information for ops and dev transfer as it relates to infrastructure that utilizes Podman.  This page
   125  includes tables showing Docker commands and their Podman equivalent commands.
   126  
   127  **[Tutorials](docs/tutorials)**
   128  Tutorials on using Podman.
   129  
   130  **[Remote Client](https://github.com/containers/podman/blob/main/docs/tutorials/remote_client.md)**
   131  A brief how-to on using the Podman remote client.
   132  
   133  **[Basic Setup and Use of Podman in a Rootless environment](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md)**
   134  A tutorial showing the setup and configuration necessary to run Rootless Podman.
   135  
   136  **[Release Notes](RELEASE_NOTES.md)**
   137  Release notes for recent Podman versions.
   138  
   139  **[Contributing](CONTRIBUTING.md)**
   140  Information about contributing to this project.
   141  
   142  [spec-hooks]: https://github.com/opencontainers/runtime-spec/blob/v1.0.2/config.md#posix-platform-hooks
   143  
   144  ## Buildah and Podman relationship
   145  
   146  Buildah and Podman are two complementary open-source projects that are
   147  available on most Linux platforms and both projects reside at
   148  [GitHub.com](https://github.com) with Buildah
   149  [here](https://github.com/containers/buildah) and Podman
   150  [here](https://github.com/containers/podman).  Both, Buildah and Podman are
   151  command line tools that work on Open Container Initiative (OCI) images and
   152  containers.  The two projects differentiate in their specialization.
   153  
   154  Buildah specializes in building OCI images.  Buildah's commands replicate all
   155  of the commands that are found in a Dockerfile.  This allows building images
   156  with and without Dockerfiles while not requiring any root privileges.
   157  Buildah’s ultimate goal is to provide a lower-level coreutils interface to
   158  build images.  The flexibility of building images without Dockerfiles allows
   159  for the integration of other scripting languages into the build process.
   160  Buildah follows a simple fork-exec model and does not run as a daemon
   161  but it is based on a comprehensive API in golang, which can be vendored
   162  into other tools.
   163  
   164  Podman specializes in all of the commands and functions that help you to maintain and modify
   165  OCI images, such as pulling and tagging.  It also allows you to create, run, and maintain those containers
   166  created from those images.  For building container images via Dockerfiles, Podman uses Buildah's
   167  golang API and can be installed independently from Buildah.
   168  
   169  A major difference between Podman and Buildah is their concept of a container.  Podman
   170  allows users to create "traditional containers" where the intent of these containers is
   171  to be long lived.  While Buildah containers are really just created to allow content
   172  to be added back to the container image.  An easy way to think of it is the
   173  `buildah run` command emulates the RUN command in a Dockerfile while the `podman run`
   174  command emulates the `docker run` command in functionality.  Because of this and their underlying
   175  storage differences, you can not see Podman containers from within Buildah or vice versa.
   176  
   177  In short, Buildah is an efficient way to create OCI images while Podman allows
   178  you to manage and maintain those images and containers in a production environment using
   179  familiar container cli commands.  For more details, see the
   180  [Container Tools Guide](https://github.com/containers/buildah/tree/main/docs/containertools).
   181  
   182  ## Podman Hello
   183  ```
   184  $ podman run quay.io/podman/hello
   185  Trying to pull quay.io/podman/hello:latest...
   186  Getting image source signatures
   187  Copying blob a6b3126f3807 done
   188  Copying config 25c667d086 done
   189  Writing manifest to image destination
   190  Storing signatures
   191  !... Hello Podman World ...!
   192  
   193           .--"--.
   194         / -     - \
   195        / (O)   (O) \
   196     ~~~| -=(,Y,)=- |
   197      .---. /`  \   |~~
   198   ~/  o  o \~~~~.----. ~~
   199    | =(X)= |~  / (O (O) \
   200     ~~~~~~~  ~| =(Y_)=-  |
   201    ~~~~    ~~~|   U      |~~
   202  
   203  Project:   https://github.com/containers/podman
   204  Website:   https://podman.io
   205  Documents: https://docs.podman.io
   206  Twitter:   @Podman_io
   207  ```