spud/podman/main.go

// The Podman package handles any interactions with Podman entities or state.
package podman

import (
	"log"
	"os/exec"

	service_definition "spud/service_definition"
)

// Creates a Podman volume of name `name` if it does not exist.
//
// If the volume exists, then behaviour depends on `existsOk`:
// - If `existsOk` is truthy, then the already-exists error is ignored and
//   nothing is done;
// - Else, an error is returned.
func CreateVolume(name string, existsOk bool) error {
	args := []string{"volume", "create", name}

	if existsOk {
		args = append(args, "--ignore")
	}

	command := exec.Command("podman", args...)

	if err := command.Run(); err != nil {

		return err
	}

	log.Printf("✅ Created volume \"%s\".", name)

	return nil
}

// Creates a Podman pod to keep related containers together.
//
// The pod created will expose ports necessary for individual containers
// to be accessible from the host.
func CreatePod(name string, ports []service_definition.PortMapping) error {
	args := []string{"pod", "create", "--replace"}

	for _, portMapping := range ports {
		portArgs := []string{"-p", portMapping.Host + ":" + portMapping.Container}
		args = append(args, portArgs...)
	}

	args = append(args, name)

	command := exec.Command("podman", args...)

	if err := command.Run(); err != nil {
		return err
	}

	log.Printf("✅ Created pod \"%s\".", name)

	return nil
}

// Stops a running pod.
func StopPod(name string) error {
	args := []string{"pod", "stop", name}

	command := exec.Command("podman", args...)

	if err := command.Run(); err != nil {
		return err
	}

	log.Printf("✅ Stopped pod \"%s\" and child containers.", name)

	return nil

}

// Creates individual containers.
// 
// Individual containers do not expose any ports by themselves, these
// are handled by the pod that wraps the containers.
func CreateContainer(definition service_definition.ContainerDefinition, knownVolumes map[string]string, service string) error {
	namespacedContainerName := service + "_" + definition.Name

	args := []string{
		"run",
		"-d",
		"--name",
		namespacedContainerName,
		"--pod",
		service,
		"--replace",
	}

	for _, volume := range definition.Volumes {
		var host string
		container := volume.Container

		if volume.Name != "" {
			namespacedName := service + "_" + volume.Name
			host = namespacedName
		} else if volume.Host != "" {
			host = volume.Host
		} else {
			log.Fatal("Invalid volume source configuration")
		}

		arg := []string{"-v", host + ":" + container}

		args = append(args, arg...)
	}

	args = append(args, definition.Image)

	for _, extra := range definition.ExtraArgs {
		args = append(args, extra)
	}

	command := exec.Command("podman", args...)

	if err := command.Start(); err != nil {
		log.Fatal("Failed to start")
		return err
	}

	if err := command.Wait(); err != nil {
		return err
	}

	log.Printf("✅ Started container \"%s\".", namespacedContainerName)

	return nil
}