CLI tool for spawning and running containers according to the OCI specification
Go Shell C Other
Latest commit 0fefa36 Jan 20, 2017 @dqminh dqminh committed on GitHub Merge pull request #1278 from datawolf/scanner
move error check out of the for loop
Permalink
Failed to load latest commit information.
Godeps Bump runtime-spec to v1.0.0-rc3 Dec 17, 2016
contrib contrib: add recvtty proof-of-concept Dec 1, 2016
libcontainer Merge pull request #1278 from datawolf/scanner Jan 20, 2017
man rename ocitools to oci-runtime-tool Dec 16, 2016
script Add shfmt to the validate make target Nov 17, 2016
tests/integration Add integration for update rt period and runtime Dec 27, 2016
.gitignore contrib: add recvtty proof-of-concept Dec 1, 2016
.pullapprove.yml Disallow self-LGTMs Jun 1, 2016
.travis.yml travis: add travis-ci Dec 30, 2016
CONTRIBUTING.md *: add information about security mailing list Dec 3, 2016
Dockerfile Bump golang to 1.7.4 Jan 12, 2017
LICENSE Initial commit of runc binary Jun 22, 2015
MAINTAINERS MAINTAINERS: add Aleksa Sarai to maintainers Mar 15, 2016
MAINTAINERS_GUIDE.md 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
PRINCIPLES.md Move libcontainer documenation to root of repo Jun 26, 2015
README.md Add badge for Go Report Card Jan 4, 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 Check args numbers before application start Nov 29, 2016
exec.go Fix regression of exec command Jan 10, 2017
kill.go kill: make second argument optional Jan 19, 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 github.com/codegangsta/cli by github.com/urfave/cli Jun 6, 2016
main_unix.go Add error return to action function signature Jun 7, 2016
main_unsupported.go Replace github.com/codegangsta/cli by github.com/urfave/cli Jun 6, 2016
pause.go Check args numbers before application start Nov 29, 2016
ps.go Simplify error handling on function return Jan 6, 2017
restore.go Fix error shadow and error check warnings Jan 7, 2017
rlimit_linux.go Fixing rlimit sigpending value Apr 3, 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 Simplify error handling on function return Jan 6, 2017
utils.go Simplify error handling on function return Jan 6, 2017
utils_linux.go Fix error shadow and error check warnings Jan 7, 2017

README.md

runc

Build Status Go Report Card

Introduction

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

Releases

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.

Security

If you wish to report a security issue, please disclose the issue responsibly to security@opencontainers.org.

Building

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

make
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": [
                        "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                        "TERM=xterm"
                ],
                "cwd": "/",
                "capabilities": [
                        "CAP_AUDIT_WRITE",
                        "CAP_KILL",
                        "CAP_NET_BIND_SERVICE"
                ],
                "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.

Supervisors

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.

[Unit]
Description=Start My Container

[Service]
Type=forking
ExecStart=/usr/local/sbin/runc run -d --pid-file /run/mycontainerid.pid mycontainerid
ExecStopPost=/usr/local/sbin/runc delete mycontainerid
WorkingDirectory=/mycontainer
PIDFile=/run/mycontainerid.pid

[Install]
WantedBy=multi-user.target