go get



Containerd is a daemon to control runC, built for performance and density. Containerd leverages runC's advanced features such as seccomp and user namespace support as well as checkpoint and restore for cloning and live migration of containers.


For more documentation on various subjects refer to the /docs directory in this repository.


You will need to make sure that you have Go installed on your system and the containerd repository is cloned in your $GOPATH. You will also need to make sure that you have all the dependencies cloned as well. Currently, contributing to containerd is not for the first time devs as many dependencies are not vendored and work is being completed at a high rate.

After that just run make and the binaries for the daemon and client will be localed in the bin/ directory.


The easy way to test and use containerd is to view the releases page for binary downloads. We encourage everyone to use containerd this way until it is out of alpha status.


Starting 1000 containers concurrently runs at 126-140 containers per second.

Overall start times:

[containerd] 2015/12/04 15:00:54   count:        1000
[containerd] 2015/12/04 14:59:54   min:          23ms
[containerd] 2015/12/04 14:59:54   max:         355ms
[containerd] 2015/12/04 14:59:54   mean:         78ms
[containerd] 2015/12/04 14:59:54   stddev:       34ms
[containerd] 2015/12/04 14:59:54   median:       73ms
[containerd] 2015/12/04 14:59:54   75%:          91ms
[containerd] 2015/12/04 14:59:54   95%:         123ms
[containerd] 2015/12/04 14:59:54   99%:         287ms
[containerd] 2015/12/04 14:59:54   99.9%:       355ms


Currently containerd only outputs metrics to stdout but will support dumping to various backends in the future.

[containerd] 2015/12/16 11:48:28 timer container-start-time
[containerd] 2015/12/16 11:48:28   count:              22
[containerd] 2015/12/16 11:48:28   min:          25425883
[containerd] 2015/12/16 11:48:28   max:         113077691
[containerd] 2015/12/16 11:48:28   mean:         68386923.27
[containerd] 2015/12/16 11:48:28   stddev:       20928453.26
[containerd] 2015/12/16 11:48:28   median:       65489003.50
[containerd] 2015/12/16 11:48:28   75%:          82393210.50
[containerd] 2015/12/16 11:48:28   95%:         112267814.75
[containerd] 2015/12/16 11:48:28   99%:         113077691.00
[containerd] 2015/12/16 11:48:28   99.9%:       113077691.00
[containerd] 2015/12/16 11:48:28   1-min rate:          0.00
[containerd] 2015/12/16 11:48:28   5-min rate:          0.01
[containerd] 2015/12/16 11:48:28   15-min rate:         0.01
[containerd] 2015/12/16 11:48:28   mean rate:           0.03
[containerd] 2015/12/16 11:48:28 counter containers
[containerd] 2015/12/16 11:48:28   count:               1
[containerd] 2015/12/16 11:48:28 counter events
[containerd] 2015/12/16 11:48:28   count:              87
[containerd] 2015/12/16 11:48:28 counter events-subscribers
[containerd] 2015/12/16 11:48:28   count:               2
[containerd] 2015/12/16 11:48:28 gauge goroutines
[containerd] 2015/12/16 11:48:28   value:              38
[containerd] 2015/12/16 11:48:28 gauge fds
[containerd] 2015/12/16 11:48:28   value:              18

Daemon options

$ containerd -h

   containerd - High performance container daemon

   containerd [global options] command [command options] [arguments...]

   0.1.0 commit: 54c213e8a719d734001beb2cb8f130c84cc3bd20

   help, h      Shows a list of commands or help for one command

   --debug                                              enable debug output in the logs
   --state-dir "/run/containerd"                        runtime state directory
   --metrics-interval "5m0s"                            interval for flushing metrics to the store
   --listen, -l "/run/containerd/containerd.sock"       Address on which GRPC API will listen
   --runtime, -r "runc"                                 name of the OCI compliant runtime to use when executing containers
   --graphite-address                                   Address of graphite server
   --help, -h                                           show help
   --version, -v                                        print the version


The current roadmap and milestones for alpha and beta completion are in the github issues on this repository. Please refer to these issues for what is being worked on and completed for the various stages of development.



The API for containerd is with GRPC over a unix socket located at the default location of /run/containerd/containerd.sock.

At this time please refer to the proto at for the API methods and types.
There is a Go implementation and types checked into this repository but alternate language implementations can be created using the grpc and protoc toolchain.

containerd CLI

There is a default cli named ctr based on the GRPC api. This cli will allow you to create and manage containers run with containerd.

$ ctr -h
   ctr - High performance container daemon cli

   ctr [global options] command [command options] [arguments...]

   0.1.0 commit: 54c213e8a719d734001beb2cb8f130c84cc3bd20

   checkpoints  list all checkpoints
   containers   interact with running containers
   events       receive events from the containerd daemon
   state        get a raw dump of the containerd state
   help, h      Shows a list of commands or help for one command

   --debug                                      enable debug output in the logs
   --address "/run/containerd/containerd.sock"  address of GRPC API
   --help, -h                                   show help
   --version, -v                                print the version

Starting a container

$ ctr containers start -h
   ctr containers start - start a container

   ctr containers start [command options] [arguments...]

   --checkpoint, -c                             checkpoint to start the container from
   --attach, -a                                 connect to the stdio of the container
   --label, -l [--label option --label option]  set labels for the container
$ sudo ctr containers start redis /containers/redis

Note: /containers/redis is the path of bundle you have to prepare before running a contianer, see bundle to get more information.

Listing containers

$ sudo ctr containers
ID                  PATH                STATUS              PROCESSES
1                   /containers/redis   running             14063
19                  /containers/redis   running             14100
14                  /containers/redis   running             14117
4                   /containers/redis   running             14030
16                  /containers/redis   running             14061
3                   /containers/redis   running             14024
12                  /containers/redis   running             14097
10                  /containers/redis   running             14131
18                  /containers/redis   running             13977
13                  /containers/redis   running             13979
15                  /containers/redis   running             13998
5                   /containers/redis   running             14021
9                   /containers/redis   running             14075
6                   /containers/redis   running             14107
2                   /containers/redis   running             14135
11                  /containers/redis   running             13978
17                  /containers/redis   running             13989
8                   /containers/redis   running             14053
7                   /containers/redis   running             14022
0                   /containers/redis   running             14006

Kill a container's process

$ ctr containers kill -h
   ctr containers kill - send a signal to a container or its processes

   ctr containers kill [command options] [arguments...]

   --pid, -p "init"     pid of the process to signal within the container
   --signal, -s "15"    signal to send to the container

Exec another process into a container

$ ctr containers exec -h
   ctr containers exec - exec another process in an existing container

   ctr containers exec [command options] [arguments...]

   --id                                         container id to add the process to
   --pid                                        process id for the new process
   --attach, -a                                 connect to the stdio of the container
   --cwd                                        current working directory for the process
   --tty, -t                                    create a terminal for the process
   --env, -e [--env option --env option]        environment variables for the process
   --uid, -u "0"                                user id of the user for the process
   --gid, -g "0"                                group id of the user for the process

Stats for a container

$ ctr containers stats -h
   ctr containers stats - get stats for running container

   ctr containers stats [arguments...]

List checkpoints

$ sudo ctr checkpoints redis
NAME                TCP                 UNIX SOCKETS        SHELL
test                false               false               false
test2               false               false               false

Create a new checkpoint

$ ctr checkpoints create -h
   ctr checkpoints create - create a new checkpoint for the container

   ctr checkpoints create [command options] [arguments...]

   --tcp                persist open tcp connections
   --unix-sockets       perist unix sockets
   --exit               exit the container after the checkpoint completes successfully
   --shell              checkpoint shell jobs

Get events

$ sudo ctr events
TYPE                ID                  PID                 STATUS
exit                redis               24761               0

Sign your work

The sign-off is a simple line at the end of the explanation for the patch. Your signature certifies that you wrote the patch or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple: if you can certify the below (from

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

Then you just add a line to every git commit message:

Signed-off-by: Joe Smith <>

Use your real name (sorry, no pseudonyms or anonymous contributions.)

If you set your and git configs, you can sign your commit automatically with git commit -s.

Copyright and license

Copyright © 2016 Docker, Inc. All rights reserved, except as follows. Code is released under the Apache 2.0 license. The 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 "". You may obtain a duplicate copy of the same license, titled CC-BY-SA-4.0, at