Initial commit

Signed-off-by: Brian DeHamer <brian@dehamer.com>

updater/updater.go

@@ -0,0 +1,81 @@
+package updater
+
+import (
+	"log"
+
+	"github.com/samalba/dockerclient"
+)
+
+var (
+	client dockerclient.Client
+)
+
+func init() {
+	docker, err := dockerclient.NewDockerClient("unix:///var/run/docker.sock", nil)
+	if err != nil {
+		log.Fatalf("Error instantiating Docker client: %s\n", err)
+	}
+
+	client = docker
+}
+
+func Run() error {
+	containers, _ := client.ListContainers(false, false, "")
+
+	for _, container := range containers {
+
+		oldContainerInfo, _ := client.InspectContainer(container.Id)
+		name := oldContainerInfo.Name
+		oldImageId := oldContainerInfo.Image
+		log.Printf("Running: %s (%s)\n", container.Image, oldImageId)
+
+		oldImageInfo, _ := client.InspectImage(oldImageId)
+
+		// First check to see if a newer image has already been built
+		newImageInfo, _ := client.InspectImage(container.Image)
+
+		if newImageInfo.Id == oldImageInfo.Id {
+			_ = client.PullImage(container.Image, nil)
+			newImageInfo, _ = client.InspectImage(container.Image)
+		}
+
+		newImageId := newImageInfo.Id
+		log.Printf("Latest:  %s (%s)\n", container.Image, newImageId)
+
+		if newImageId != oldImageId {
+			log.Printf("Restarting %s with new image\n", name)
+			if err := stopContainer(oldContainerInfo); err != nil {
+			}
+
+			config := GenerateContainerConfig(oldContainerInfo, oldImageInfo.Config)
+
+			hostConfig := oldContainerInfo.HostConfig
+			_ = startContainer(name, config, hostConfig)
+		}
+	}
+
+	return nil
+}
+
+func stopContainer(container *dockerclient.ContainerInfo) error {
+	signal := "SIGTERM"
+
+	if sig, ok := container.Config.Labels["com.centurylinklabs.watchtower.stop-signal"]; ok {
+		signal = sig
+	}
+
+	if err := client.KillContainer(container.Id, signal); err != nil {
+		return err
+	}
+
+	return client.RemoveContainer(container.Id, true, false)
+}
+
+func startContainer(name string, config *dockerclient.ContainerConfig, hostConfig *dockerclient.HostConfig) error {
+	newContainerId, err := client.CreateContainer(config, name)
+	if err != nil {
+		return err
+	}
+
+	return client.StartContainer(newContainerId, hostConfig)
+}