# cri
<p align="center">
<img src="https://kubernetes.io/images/favicon.png" width="50" height="50">
<img src="https://containerd.io/img/logos/icon/black/containerd-icon-black.png" width="50" >
</p>

*Note: The standalone `cri-containerd` binary is end-of-life. `cri-containerd` is
transitioning from a standalone binary that talks to containerd to a plugin within
containerd. This github branch is for the `cri` plugin. See
[standalone-cri-containerd branch](https://github.com/containerd/cri/tree/standalone-cri-containerd)
for information about the standalone version of `cri-containerd`.*

*Note: You need to [drain your node](https://kubernetes.io/docs/tasks/administer-cluster/safely-drain-node/) before upgrading from standalone `cri-containerd` to containerd with `cri` plugin.*

[![Build Status](https://api.travis-ci.org/containerd/cri.svg?style=flat-square)](https://travis-ci.org/containerd/cri)
[![Go Report Card](https://goreportcard.com/badge/github.com/containerd/cri)](https://goreportcard.com/report/github.com/containerd/cri)

`cri` is a [containerd](https://containerd.io/) plugin implementation of Kubernetes [container runtime interface (CRI)](https://github.com/kubernetes/cri-api/blob/master/pkg/apis/runtime/v1alpha2/api.proto).

With it, you could run Kubernetes using containerd as the container runtime.
![cri](./docs/cri.png)
## Current Status
`cri` is a native plugin of containerd 1.1 and above. It is built into containerd and enabled by default.

`cri` is in GA:
* It is feature complete.
* It (the GA version) works with Kubernetes 1.10 and above.
* It has passed all [CRI validation tests](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-node/cri-validation.md).
* It has passed all [node e2e tests](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-node/e2e-node-tests.md).
* It has passed all [e2e tests](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-testing/e2e-tests.md).

See [test dashboard](https://k8s-testgrid.appspot.com/sig-node-containerd)
## Support Metrics
| CRI-Containerd Version | Containerd Version | Kubernetes Version | CRI Version |
|:----------------------:|:------------------:|:------------------:|:-----------:|
|     v1.0.0-alpha.x     |                    |      1.7, 1.8      |   v1alpha1  |
|      v1.0.0-beta.x     |                    |        1.9         |   v1alpha1  |
|       End-Of-Life      | v1.1 (End-Of-Life) |        1.10+       |   v1alpha2  |
|                        |  v1.2 (Extended)   |        1.10+       |   v1alpha2  |
|                        |        v1.3        |        1.12+       |   v1alpha2  |
|                        |        v1.4        |      1.19+ (rc)    |   v1alpha2  |

**Note:** The support table above specifies the Kubernetes Version that was supported at time of release of the containerd - cri integration.

The following is the current support table for containerd CRI integration taking into account that Kubernetes only supports n-3 minor release versions.

| Containerd Version | Kubernetes Version | CRI Version |
|:------------------:|:------------------:|:-----------:|
|        v1.2        |        1.15+       |   v1alpha2  |
|        v1.3        |        1.15+       |   v1alpha2  |
|        v1.4        |      1.19+ (rc)    |   v1alpha2  |

## Production Quality Cluster on GCE
For a production quality cluster on GCE brought up with `kube-up.sh` refer [here](docs/kube-up.md).
## Installing with Ansible and Kubeadm
For a multi node cluster installer and bring up steps using ansible and kubeadm refer [here](contrib/ansible/README.md).
## Custom Installation
For non ansible users, you can download the `cri-containerd` release tarball and deploy
kubernetes cluster using kubeadm as described [here](docs/installation.md).
## Getting Started for Developers
### Binary Dependencies and Specifications
The current release of the `cri` plugin has the following dependencies:
* [containerd](https://github.com/containerd/containerd)
* [runc](https://github.com/opencontainers/runc)
* [CNI](https://github.com/containernetworking/cni)

See [versions](./vendor.conf) of these dependencies `cri` is tested with.

As containerd and runc move to their respective general availability releases,
we will do our best to rebase/retest `cri` with these releases on a
weekly/monthly basis. Similarly, given that `cri` uses the Open
Container Initiative (OCI) [image](https://github.com/opencontainers/image-spec)
and [runtime](https://github.com/opencontainers/runtime-spec) specifications, we
will also do our best to update `cri` to the latest releases of these
specifications as appropriate.
### Install Dependencies
1. Install development libraries:
* **libseccomp development library.** Required by `cri` and runc seccomp support. `libseccomp-dev` (Ubuntu, Debian) / `libseccomp-devel`
(Fedora, CentOS, RHEL). On releases of Ubuntu <=Trusty and Debian <=jessie a
backport version of `libseccomp-dev` is required. See [travis.yml](.travis.yml) for an example on trusty.
* **btrfs development library.** Required by containerd btrfs support. `btrfs-tools`(Ubuntu, Debian) / `btrfs-progs-devel`(Fedora, CentOS, RHEL)
2. Install **`pkg-config`** (required for linking with `libseccomp`).
3. Install and setup a Go 1.13.15 development environment.
4. Make a local clone of this repository.
5. Install binary dependencies by running the following command from your cloned `cri/` project directory:
```bash
# Note: install.deps installs the above mentioned runc, containerd, and CNI
# binary dependencies. install.deps is only provided for general use and ease of
# testing. To customize `runc` and `containerd` build tags and/or to configure
# `cni`, please follow instructions in their documents.
make install.deps
```
### Build and Install `cri`
To build and install a version of containerd with the `cri` plugin, enter the
following commands from your `cri` project directory:
```bash
make
sudo make install
```
*NOTE: The version of containerd built and installed from the `Makefile` is only for
testing purposes. The version tag carries the suffix "-TEST".*
#### Build Tags
`cri` supports optional build tags for compiling support of various features.
To add build tags to the make option the `BUILD_TAGS` variable must be set.

```bash
make BUILD_TAGS='seccomp apparmor selinux'
```

| Build Tag | Feature                            | Dependency                      |
|-----------|------------------------------------|---------------------------------|
| seccomp   | syscall filtering                  | libseccomp development library  |
| selinux   | selinux process and mount labeling | <none>                          |
| apparmor  | apparmor profile support           | <none>                          |
### Validate Your `cri` Setup
A Kubernetes incubator project called [cri-tools](https://github.com/kubernetes-sigs/cri-tools)
includes programs for exercising CRI implementations such as the `cri` plugin.
More importantly, cri-tools includes the program `critest` which is used for running
[CRI Validation Testing](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-node/cri-validation.md).

Run the CRI Validation test to validate your installation of `containerd` with `cri` built in:
```bash
make test-cri
```
### Running a Kubernetes local cluster
If you already have a working development environment for supported Kubernetes
version, you can try `cri` in a local cluster:

1. Start the version of `containerd` with `cri` plugin that you built and installed
above as root in a first terminal:
```bash
sudo containerd
```
2. From the Kubernetes project directory startup a local cluster using `containerd`:
```bash
CONTAINER_RUNTIME=remote CONTAINER_RUNTIME_ENDPOINT='unix:///run/containerd/containerd.sock' ./hack/local-up-cluster.sh
```
### Test
See [here](./docs/testing.md) for information about test.
## Using crictl
See [here](./docs/crictl.md) for information about using `crictl` to debug
pods, containers, and images.
## Configurations
See [here](./docs/config.md) for information about how to configure cri plugins
and [here](https://github.com/containerd/containerd/blob/master/docs/man/containerd-config.8.md)
for information about how to configure containerd
## Documentation
See [here](./docs) for additional documentation.
## Communication
For async communication and long running discussions please use issues and pull
requests on this github repo. This will be the best place to discuss design and
implementation.

For sync communication we have a community slack with a #containerd channel that
everyone is welcome to join and chat about development.

**Slack:** Catch us in the #containerd and #containerd-dev channels on dockercommunity.slack.com.
[Click here for an invite to docker community slack.](https://dockr.ly/slack)

## Other Communications
As this project is tightly coupled to CRI and CRI-Tools and they are Kubernetes
projects, some of our project communications take place in the Kubernetes' SIG:
`sig-node.`

For more information about `sig-node`, `CRI`, and the `CRI-Tools` projects:
* [sig-node community site](https://github.com/kubernetes/community/tree/master/sig-node)
* Slack: `#sig-node` channel in Kubernetes (kubernetes.slack.com)
* Mailing List: https://groups.google.com/forum/#!forum/kubernetes-sig-node

### Reporting Security Issues

__If you are reporting a security issue, please reach out discreetly at security@containerd.io__.

## Licenses
The containerd codebase is released under the [Apache 2.0 license](https://github.com/containerd/containerd/blob/master/LICENSE.code).
The README.md file, and files in the "docs" folder are licensed under the
Creative Commons Attribution 4.0 International License under the terms and
conditions set forth in the file "[LICENSE.docs](https://github.com/containerd/containerd/blob/master/LICENSE.docs)". You may obtain a duplicate
copy of the same license, titled CC-BY-4.0, at http://creativecommons.org/licenses/by/4.0/.

## Project details
cri is a containerd sub-project. This project was originally established in
April of 2017 in the Kubernetes Incubator program. After reaching the Beta
stage, In January of 2018, the project was merged into [containerd](https://github.com/containerd/containerd).
As a containerd sub-project, you will find the:
* [Project governance](https://github.com/containerd/project/blob/master/GOVERNANCE.md),
* [Maintainers](https://github.com/containerd/project/blob/master/MAINTAINERS),
* and [Contributing guidelines](https://github.com/containerd/project/blob/master/CONTRIBUTING.md)

information in our [`containerd/project`](https://github.com/containerd/project) repository.
