Repository files navigation

containerd is an industry-standard container runtime with an emphasis on simplicity, robustness, and portability. It is available as a daemon for Linux and Windows, which can manage the complete container lifecycle of its host system: image transfer and storage, container execution and supervision, low-level storage and network attachments, etc.

containerd is a member of CNCF with'graduated' status.

containerd is designed to be embedded into a larger system, rather than being used directly by developers or end-users.

Seedocs/containerd-2.0.md.

We are a large inclusive OSS project that is welcoming help of any kind shape or form:

• Documentation help is needed to make the product easier to consume and extend.
• We need OSS community outreach/organizing help to get the word out; manageand create messaging and educational content; and help with social media, community forums/groups, and google groups.
• We are actively inviting newsecurity advisors to join the team.
• New subprojects are being created, core and non-core that could use additional development help.
• Each of thecontainerd projects has a list of issues currently being worked on or that need help resolving.
  • If the issue has not already been assigned to someone or has not made recent progress, and you are interested, please inquire.
  • If you are interested in starting with a smaller/beginner-level issue, look for issues with anexp/beginner tag, for examplecontainerd/containerd beginner issues.

See our documentation oncontainerd.io:

• for ops and admins
• namespaces
• client options

To get started contributing to containerd, seeCONTRIBUTING.

If you are interested in trying out containerd see our example atGetting Started.

There are nightly builds available for downloadhere.Binaries are generated frommain branch every night forLinux andWindows.

Please be aware: nightly builds might have critical bugs, it's not recommended for use in production and no support provided.

Thek8s CI dashboard group for containerd contains test results regardingthe health of kubernetes when run against main and a number of containerd release branches.

• containerd-periodics

Runtime requirements for containerd are very minimal. Most interactions withthe Linux and Windows container feature sets are handled viarunc and/orOS-specific libraries (e.g.hcsshim for Microsoft).The current required version ofrunc is described inRUNC.md.

There are specific featuresused by containerd core code and snapshotters that will require a minimum kernelversion on Linux. With the understood caveat of distro kernel versioning, areasonable starting point for Linux is a minimum 4.x kernel version.

The overlay filesystem snapshotter, used by default, uses features that werefinalized in the 4.x kernel series. If you choose to use btrfs, there maybe more flexibility in kernel version (minimum recommended is 3.18), but willrequire the btrfs kernel module and btrfs tools to be installed on your Linuxdistribution.

To use Linux checkpoint and restore features, you will needcriu installed onyour system. See more details inCheckpoint and Restore.

Build requirements for developers are listed inBUILDING.

Any registry which is compliant with theOCI Distribution Specificationis supported by containerd.

For configuring registries, seeregistry host configuration documentation

For a detailed overview of containerd's core concepts and the features it supports,please refer to theFEATURES.MD document.

Please seeRELEASES.md for details on versioning and stabilityof containerd components.

Downloadable 64-bit Intel/AMD binaries of all official releases are available onourreleases page.

For other architectures and distribution support, you will find that manyLinux distributions package their own containerd and provide it across severalarchitectures, such asCanonical's Ubuntu packaging.

Starting with containerd 1.4, the urfave client feature for auto-creation of bash and zshautocompletion data is enabled. To use the autocomplete feature in a bash shell for example, sourcethe autocomplete/ctr file in your.bashrc, or manually like:

$ source ./contrib/autocomplete/ctr

For bash, copy thecontrib/autocomplete/ctr script into/etc/bash_completion.d/ and rename it toctr. Thezsh_autocompletefile is also available and can be used similarly for zsh users.

Provide documentation to users tosource this file into their shell ifyou don't place the autocomplete file in a location where it is automaticallyloaded for the user's shell environment.

cri is acontainerd plugin implementation of the Kubernetescontainer runtime interface (CRI). With it, you are able to use containerd as the container runtime for a Kubernetes cluster.

cri is a native plugin of containerd. Since containerd 1.1, the cri plugin is built into the release binaries and enabled by default.

Thecri plugin has reached GA status, representing that it is:

• Feature complete
• Works with Kubernetes 1.10 and above
• Passes allCRI validation tests.
• Passes allnode e2e tests.
• Passes alle2e tests.

See results on the containerd k8stest dashboard

A Kubernetes incubator project,cri-tools, includes programs for exercising CRI implementations. More importantly, cri-tools includes the programcritest which is used for runningCRI Validation Testing.

• Installing with Ansible and Kubeadm
• For Non-Ansible Users, Preforming a Custom Installation Using the Release Tarball and Kubeadm
• CRI Plugin Testing Guide
• Debugging Pods, Containers, and Images withcrictl
• Configuringcri Plugins
• Configuring containerd

For async communication and long-running discussions please use issues and pull requests on the GitHub repo.This will be the best place to discuss design and implementation.

For sync communication catch us in the#containerd and#containerd-dev Slack channels on Cloud Native Computing Foundation's (CNCF) Slack -cloud-native.slack.com. Everyone is welcome to join and chat.Get Invite to CNCF Slack.

Join our next community meeting hosted on Zoom. The schedule is posted on theCNCF Calendar (search 'containerd' to filter).

Security audits for the containerd project are hosted on our website. Please see thesecurity page at containerd.io for more information.

Please follow the instructions atcontainerd/project

The containerd codebase is released under theApache 2.0 license.The README.md file and files in the "docs" folder are licensed under theCreative Commons Attribution 4.0 International License. You may obtain acopy of the license, titled CC-BY-4.0, athttp://creativecommons.org/licenses/by/4.0/.

containerd is the primary open source project within the broader containerd GitHub organization.However, all projects within the repo have common maintainership, governance, and contributingguidelines which are stored in aproject repository commonly for all containerd projects.

Please find all these core project documents, including the:

• Project governance,
• Maintainers,
• andContributing guidelines

information in ourcontainerd/project repository.

Interested to see who is using containerd? Are you using containerd in a project?Please add yourself via pull request to ourADOPTERS.md file.