This is intended to be the second-last RC release, with -rc92 having
very few large changes so that we can release runc 1.0 (at long last).

 * The long-awaited hooks changes have been merged into runc. This was
   one of the few remaining spec-related issues which were blocking us
   from releasing runc 1.0. Existing hook users will not be affected by
   this change, but runc now supports additional hooks that we expect
   users to migrate to eventually. The new hooks are:

    - createRuntime (replacement for the now-deprecated prestart)
    - createContainer
    - startContainer

 * A large amount of effort has been undertaken to support cgroupv2
   within runc. The support is still considered experimental, but it is
   mostly functional at this point. Please report any bugs you find when
   running under cgroupv2-only systems.

 * A minor-severity security bug was fixed[1]. The devices list would
   be in allow-by-default mode from the outset, meaning that users would
   have to explicitly specify they wish to deny all device access at the
   beginning of the configuration. While this would normally be
   considered a high-severity vulnerability, all known users of runc had
   worked around this issue several years ago (hence why this fairly
   obvious bug was masked).

   In addition, the devices list code has been massively improved such
   that it will attempt to avoid causing spurrious errors in the
   container (such as while writing to /dev/null) when doing devices
   cgroup updates.

 * A security audit of runc was conducted in 2019, and the report PDF is
   now included in the runc repository. The previous release of runc
   has already addressed the security issues found in that report.

Thanks to the following people who made this release possible:

 * Adrian Reber <areber@redhat.com>
 * Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
 * Alban Crequy <alban@kinvolk.io>
 * Aleksa Sarai <asarai@suse.de>
 * Alice Frosi <afrosi@de.ibm.com>
 * Amye Scavarda Perrin <amye@linuxfoundation.org>
 * Andrei Vagin <avagin@gmail.com>
 * Boris Popovschi <zyqsempai@mail.ru>
 * Brian Goff <cpuguy83@gmail.com>
 * Chris Aniszczyk <caniszczyk@gmail.com>
 * Danail Branekov <danailster@gmail.com>
 * Giuseppe Scrivano <gscrivan@redhat.com>
 * iwankgb <maciej.iwanowski@intel.com>
 * John Hwang <John.F.Hwang@gmail.com>
 * Katarzyna Kujawa <katarzyna.kujawa@intel.com>
 * Kenta Tada <Kenta.Tada@sony.com>
 * Kir Kolyshkin <kolyshkin@gmail.com>
 * Kir Kolyshkin <kolyshkin@users.noreply.github.com>
 * Kohei Ota <kela@inductor.me>
 * l00397676 <lujingxiao@huawei.com>
 * Lifubang <lifubang@acmcoder.com>
 * Mario Nitchev <marionitchev@gmail.com>
 * Michael Crosby <crosbymichael@gmail.com>
 * Mrunal Patel <mrunalp@gmail.com>
 * Odin Ugedal <odin@ugedal.com>
 * PaweĊ‚ Szulik <pawel.szulik@intel.com>
 * Peter Hunt <pehunt@redhat.com>
 * Pradyumna Agrawal <pradyumnaa@vmware.com>
 * Qiang Huang <h.huangqiang@huawei.com>
 * Renaud Gaubert <rgaubert@nvidia.com>
 * Sascha Grunert <sgrunert@suse.com>
 * Sebastiaan van Stijn <github@gone.nl>
 * SiYu Zhao <d.chaser.zsy@gmail.com>
 * Ted Yu <yuzhihong@gmail.com>
 * Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
 * Tianon Gravi <admwiggin@gmail.com>
 * Tobias Klauser <tklauser@distanz.ch>
 * wanghuaiqing <wanghuaiqing@loongson.cn>
 * W. Trevor King <wking@tremily.us>
 * Yulia Nedyalkova <julianedialkova@hotmail.com>
 * zyu <yuzhihong@gmail.com>

> **NOTE**: For those who are confused by the massive version jump (rc10
> to rc91), this was done to avoid issues with SemVer and lexical
> comparisons -- there haven't been 90 other release candidates. Please
> also note thatrunc 1.0.0-rc90 is identical to 1.0.0-rc10.

[1]: https://github.com/opencontainers/runc/security/advisories/GHSA-g54h-m393-cpwq

Vote: +7 -0 #0
Signed-off-by: Aleksa Sarai <asarai@suse.de>
VERSION: release 1.0.0-rc91

Signed-off-by: Mrunal Patel <mrunalp@gmail.com>
1 file changed
tree: 3616332f3cad5bed07c48e36a8b4eb3e6dbe7da5
  1. contrib/
  2. docs/
  3. libcontainer/
  4. man/
  5. script/
  6. tests/
  7. types/
  8. vendor/
  9. .gitignore
  10. .travis.yml
  11. checkpoint.go
  13. create.go
  14. delete.go
  15. Dockerfile
  16. events.go
  17. exec.go
  18. go.mod
  19. go.sum
  20. init.go
  21. kill.go
  23. list.go
  24. main.go
  27. Makefile
  28. NOTICE
  29. notify_socket.go
  30. pause.go
  32. ps.go
  33. README.md
  34. restore.go
  35. rlimit_linux.go
  36. rootless_linux.go
  37. run.go
  38. SECURITY.md
  39. signals.go
  40. spec.go
  41. start.go
  42. state.go
  43. tty.go
  44. update.go
  45. utils.go
  46. utils_linux.go
  47. Vagrantfile.centos7
  48. Vagrantfile.fedora32


Build Status Go Report Card GoDoc CII Best Practices


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.

Currently, the following features are not considered to be production-ready:


The reporting process and disclosure communications are outlined here.

Security Audit

A third party security audit was performed by Cure53, you can see the full report here.


runc currently supports the Linux platform with various architecture support. It must be built with Go version 1.13 or higher.

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

# create a 'github.com/opencontainers' in your GOPATH/src
cd github.com/opencontainers
git clone https://github.com/opencontainers/runc
cd runc

sudo make install

You can also use go get to install to your GOPATH, assuming that you have a github.com parent folder already created under src:

go get github.com/opencontainers/runc
cd $GOPATH/src/github.com/opencontainers/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, with some of them enabled by default (see BUILDTAGS in top-level Makefile).

To change build tags from the default, set the BUILDTAGS variable for make, e.g.

make BUILDTAGS='seccomp apparmor'
Build TagFeatureEnabled by defaultDependency
seccompSyscall filteringyeslibseccomp
selinuxselinux process and mount labelingyes
apparmorapparmor profile supportyes
nokmemdisable kernel memory accountingno

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"

You can run a specific integration test by setting the TESTPATH variable.

# make test TESTPATH="/checkpoint.bats"

You can run a specific rootless integration test by setting the ROOTLESS_TESTPATH variable.

# make test ROOTLESS_TESTPATH="/checkpoint.bats"

You can run a test using your container engine's flags by setting CONTAINER_ENGINE_BUILD_FLAGS and CONTAINER_ENGINE_RUN_FLAGS variables.

# make test CONTAINER_ENGINE_BUILD_FLAGS="--build-arg http_proxy=http://yourproxy/" CONTAINER_ENGINE_RUN_FLAGS="-e http_proxy=http://yourproxy/"

Dependencies Management

runc uses Go Modules for dependencies management. Please refer to Go Modules for how to add or update new dependencies. When updating dependencies, be sure that you are running Go 1.14 or newer.

# Update vendored dependencies
make vendor
# Verify all dependencies
make verify-dependencies

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.

# run as root
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": {
                        "bounding": [
                        "effective": [
                        "inheritable": [
                        "permitted": [
                        "ambient": [
                "rlimits": [
                                "type": "RLIMIT_NOFILE",
                                "hard": 1024,
                                "soft": 1024
                "noNewPrivileges": true

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

# run as root
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 allows higher level systems to augment the containers creation logic with setup of various settings after the container is created and/or before it is deleted. For example, the container's network stack is commonly set up after create but before start.

Rootless containers

runc has the ability to run containers without root privileges. This is called rootless. You need to pass some parameters to runc in order to run rootless containers. See below and compare with the previous version.

Note: In order to use this feature, “User Namespaces” must be compiled and enabled in your kernel. There are various ways to do this depending on your distribution:

  • Confirm CONFIG_USER_NS=y is set in your kernel configuration (normally found in /proc/config.gz)
  • Arch/Debian: echo 1 > /proc/sys/kernel/unprivileged_userns_clone
  • RHEL/CentOS 7: echo 28633 > /proc/sys/user/max_user_namespaces

Run the following commands as an ordinary user:

# Same as the first example
mkdir ~/mycontainer
cd ~/mycontainer
mkdir rootfs
docker export $(docker create busybox) | tar -C rootfs -xvf -

# The --rootless parameter instructs runc spec to generate a configuration for a rootless container, which will allow you to run the container as a non-root user.
runc spec --rootless

# The --root parameter tells runc where to store the container state. It must be writable by the user.
runc --root /tmp/runc run mycontainerid


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.pid mycontainerid
ExecStopPost=/usr/local/sbin/runc delete mycontainerid


cgroup v2

See ./docs/cgroup-v2.md.


The code and docs are released under the Apache 2.0 license.