`runc` currently supports running its test suite via Docker.
To run the suite just type `make test`.
```bash
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.
```bash
# make test TESTFLAGS="-run=SomeTestFunction"
```
You can run a specific integration test by setting the `TESTPATH` variable.
```bash
# make test TESTPATH="/checkpoint.bats"
```
You can run a test in your proxy environment by setting `DOCKER_BUILD_PROXY` and `DOCKER_RUN_PROXY` variables.
```bash
# make test DOCKER_BUILD_PROXY="--build-arg HTTP_PROXY=http://yourproxy/" DOCKER_RUN_PROXY="-e HTTP_PROXY=http://yourproxy/"
```
### Dependencies Management
`runc` uses [vndr](https://github.com/LK4D4/vndr) for dependencies management.
Please refer to [vndr](https://github.com/LK4D4/vndr) for how to add or update
new 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.
```bash
# create the top most bundle directory
mkdir /mycontainer
cd /mycontainer
# create the rootfs directory
mkdir rootfs
# export busybox via Docker into the rootfs directory
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](https://github.com/opencontainers/runtime-spec) repository.
```bash
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.
```bash
# 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"]`.
Now we can go through the lifecycle operations in your shell.
```bash
# 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. Run the following commands as an ordinary user:
# 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
```
#### 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.
```systemd
[Unit]
Description=Start My Container
[Service]
Type=forking
ExecStart=/usr/local/sbin/runc run -d --pid-file /run/mycontainerid.pid mycontainerid
