CLI tool for spawning and running containers according to the OCI specification
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Latest commit 02141ce Feb 23, 2017 @cyphar cyphar merge branch 'pr-1317'
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Godeps Bump runtime-spec to v1.0.0-rc3 Dec 17, 2016
contrib contrib: add recvtty proof-of-concept Dec 1, 2016
libcontainer merge branch 'pr-1317' Feb 23, 2017
man fix typo Feb 15, 2017
script Add shfmt to the validate make target Nov 17, 2016
tests/integration Reset Swap when memory is set to unlimited (-1) Feb 15, 2017
.gitignore contrib: add recvtty proof-of-concept Dec 1, 2016
.pullapprove.yml Disallow self-LGTMs Jun 1, 2016
.travis.yml update go version at travis-ci Feb 20, 2017 *: add information about security mailing list Dec 3, 2016
Dockerfile update go version at travis-ci Feb 20, 2017
LICENSE Initial commit of runc binary Jun 22, 2015
MAINTAINERS MAINTAINERS: add Aleksa Sarai to maintainers Mar 15, 2016 Update maintainers guide Jul 21, 2015
Makefile Merge pull request #1252 from FengtuWang/remove-i Jan 9, 2017
NOTICE Move libcontainer documenation to root of repo Jun 26, 2015 Move libcontainer documenation to root of repo Jun 26, 2015 Add godoc links to files Jan 21, 2017
VERSION Bump spec and version to rc2 Sep 28, 2016
checkpoint.go merge branch 'pr-1158' Dec 26, 2016
create.go merge branch 'pr-1158' Dec 26, 2016
delete.go Fix error shadow and error check warnings Jan 7, 2017
events.go Merge pull request #1205 from YuPengZTE/devError Jan 27, 2017
exec.go Fix regression of exec command Jan 10, 2017
kill.go kill: requires max 2 arguments Feb 2, 2017
list.go Check args numbers before application start Nov 29, 2016
main.go Ensure we log into logrus on command error Oct 3, 2016
main_solaris.go Replace by Jun 6, 2016
main_unix.go Add error return to action function signature Jun 7, 2016
main_unsupported.go Replace by Jun 6, 2016
pause.go Check args numbers before application start Nov 29, 2016
ps.go ps: --format value check Feb 21, 2017
restore.go Fix error shadow and error check warnings Jan 7, 2017
rlimit_linux.go error strings should not be capitalized or end with punctuation Dec 1, 2016
run.go merge branch 'pr-1158' Dec 26, 2016
signals.go *: console rewrite Dec 1, 2016
spec.go Remove unused code and unnecessary conversion Jan 7, 2017
start.go Check args numbers before application start Nov 29, 2016
state.go Check args numbers before application start Nov 29, 2016
tty.go Simplify error handling on function return Jan 6, 2017
update.go Merge pull request #1127 from boynux/fix-set-mem-to-unlimited Feb 16, 2017
utils.go kill: requires max 2 arguments Feb 2, 2017
utils_linux.go Call defer tty.Close() earlier Jan 26, 2017


Build Status Go Report Card GoDoc


runc is a CLI tool for spawning and running containers according to the OCI specification.


runc depends on and tracks the runtime-spec repository. We will try to make sure that runc and the OCI specification major versions stay in lockstep. This means that runc 1.0.0 should implement the 1.0 version of the specification.

You can find official releases of runc on the release page.


If you wish to report a security issue, please disclose the issue responsibly to


runc currently supports the Linux platform with various architecture support. It must be built with Go version 1.6 or higher in order for some features to function properly.

In order to enable seccomp support you will need to install libseccomp on your platform.

e.g. libseccomp-devel for CentOS, or libseccomp-dev for Ubuntu

Otherwise, if you do not want to build runc with seccomp support you can add BUILDTAGS="" when running make.

# create a '' in your GOPATH/src
git clone
cd runc

sudo make install

runc will be installed to /usr/local/sbin/runc on your system.

Build Tags

runc supports optional build tags for compiling support of various features. To add build tags to the make option the BUILDTAGS variable must be set.

make BUILDTAGS='seccomp apparmor'
Build Tag Feature Dependency
seccomp Syscall filtering libseccomp
selinux selinux process and mount labeling
apparmor apparmor profile support libapparmor
ambient ambient capability support kernel 4.3

Running the test suite

runc currently supports running its test suite via Docker. To run the suite just type make test.

make test

There are additional make targets for running the tests outside of a container but this is not recommended as the tests are written with the expectation that they can write and remove anywhere.

You can run a specific test case by setting the TESTFLAGS variable.

# make test TESTFLAGS="-run=SomeTestFunction"

Using runc

Creating an OCI Bundle

In order to use runc you must have your container in the format of an OCI bundle. If you have Docker installed you can use its export method to acquire a root filesystem from an existing Docker container.

# create the top most bundle directory
mkdir /mycontainer
cd /mycontainer

# create the rootfs directory
mkdir rootfs

# export busybox via Docker into the rootfs directory
docker export $(docker create busybox) | tar -C rootfs -xvf -

After a root filesystem is populated you just generate a spec in the format of a config.json file inside your bundle. runc provides a spec command to generate a base template spec that you are then able to edit. To find features and documentation for fields in the spec please refer to the specs repository.

runc spec

Running Containers

Assuming you have an OCI bundle from the previous step you can execute the container in two different ways.

The first way is to use the convenience command run that will handle creating, starting, and deleting the container after it exits.

cd /mycontainer

runc run mycontainerid

If you used the unmodified runc spec template this should give you a sh session inside the container.

The second way to start a container is using the specs lifecycle operations. This gives you more power over how the container is created and managed while it is running. This will also launch the container in the background so you will have to edit the config.json to remove the terminal setting for the simple examples here. Your process field in the config.json should look like this below with "terminal": false and "args": ["sleep", "5"].

        "process": {
                "terminal": false,
                "user": {
                        "uid": 0,
                        "gid": 0
                "args": [
                        "sleep", "5"
                "env": [
                "cwd": "/",
                "capabilities": [
                "rlimits": [
                                "type": "RLIMIT_NOFILE",
                                "hard": 1024,
                                "soft": 1024
                "noNewPrivileges": true

Now we can go though the lifecycle operations in your shell.

cd /mycontainer

runc create mycontainerid

# view the container is created and in the "created" state
runc list

# start the process inside the container
runc start mycontainerid

# after 5 seconds view that the container has exited and is now in the stopped state
runc list

# now delete the container
runc delete mycontainerid

This adds more complexity but allows higher level systems to manage runc and provides points in the containers creation to setup various settings after the container has created and/or before it is deleted. This is commonly used to setup the container's network stack after create but before start where the user's defined process will be running.


runc can be used with process supervisors and init systems to ensure that containers are restarted when they exit. An example systemd unit file looks something like this.

Description=Start My Container

ExecStart=/usr/local/sbin/runc run -d --pid-file /run/ mycontainerid
ExecStopPost=/usr/local/sbin/runc delete mycontainerid