Runtime

The Runtime component is responsible for the execution of the task run script.

There are two types of Runtime implementations that are supported out of the box with Tork:

1. Docker (default)
2. Shell

Docker

This is the default execution environment for a task. A new container is created for each task execution. Any mounts or networks defined on the task will be attached to the container on startup. Upon completion/failure of a task the container will be destroyed. This is the recomendded execution environment for a task as it provides maximum isolation from other tasks as well as from the host.

Configuration:

[runtime]
type = "docker" # this is already the default

Sandbox mode (Experimental)

Sandbox mode is an experimental security feature which forces containers to run as non-root.

When turned on (TORK_RUNTIME_DOCKER_SANDBOX=true) for a given worker, docker containers will automatically run as non-root (1000:1000) user.

If the image is already configured to run as non-root, Tork will respect that. This is useful if you want to have better control over the creation and assignment of permissions to a non-root user.

Use of this feature assumes the worker has access to the busybox:stable image (either locally or by means of a pull).

Shell

This runtime environment is only supported on unix/linux systems. When using the Shell runtime, tasks execute as a forked process on the host machine that is running Tork.

[runtime]
type = "shell"

[runtime.shell]
cmd = ["bash", "-c"] # the shell command used to execute the run script
uid = ""             # set the uid for the the task process (recommended)
gid = ""             # set the gid for the the task process (recommended)

Mounts

The Mounter component is responsible for mounting and unmounting task-defined mounts types for a given runtime.

Docker Mounts

There are several types of Mounter implementations that are supported out of the box when using the default Docker-based runtime:

1. volume - mounts and unmounts docker volumes for a given task.
2. bind - binds a host folder to a container folder for a given task.
3. tmpfs - (linux hosts only) mounts tmpfs docker volumes for a given task.

Registering a custom Mounter

To register a custom Mounter implementation for a given runtime, first follow the instructions on the Extending Tork guide to get Tork running in embedded mode.

Update your main function to make use of the engine.RegisterMounter hook:

func main() {
	if err := conf.LoadConfig(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	var mounter runtime.Mounter // implemented this interface

	engine.RegisterMounter(runtime.Docker, "mymounter", mounter)

	if err := cli.New().Run(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

Optional: You can add custom configuration to the config file if you need these for your mounter implementation:

[mounter.mymounter]
# your configs