Implement updating for semver_major

docker.go

@@ -0,0 +1,166 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"errors"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/client"
+)
+
+type LabeledContainer struct {
+	Container types.Container
+	Mode      VersioningMode
+}
+
+// Extract the repository owner (if any), repository and tag (if any) from a docker image name
+func (lc LabeledContainer) SplitImageParts() (*string, string, *string) {
+	name := lc.Container.Image
+
+	var repository string
+	var owner *string
+	var tag *string
+
+	slashIndex := strings.Index(name, "/")
+	if slashIndex >= 0 {
+		tmp := name[:slashIndex]
+		owner = &tmp
+		name = name[slashIndex+1:]
+	}
+
+	colonIndex := strings.Index(name, ":")
+	if colonIndex >= 0 {
+		tmp := name[colonIndex+1:]
+		tag = &tmp
+
+		repository = name[:colonIndex]
+	} else {
+		repository = name
+	}
+
+	return owner, repository, tag
+}
+
+func combineImageParts(owner *string, repository string, tag *string) string {
+	image := repository
+	if owner != nil {
+		image = fmt.Sprintf("%s/%s", *owner, image)
+	}
+	if tag != nil {
+		image = fmt.Sprintf("%s:%s", image, *tag)
+	}
+
+	return image
+}
+
+func getLabeledContainers(cli *client.Client) []LabeledContainer {
+	out := make([]LabeledContainer, 0)
+
+	containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("scanning running container labels")
+	for _, container := range containers {
+		fmt.Printf("- %s %s\n", container.ID[:10], container.Image)
+		for k, v := range container.Labels {
+			fmt.Printf("  - \"%s\": \"%s\"\n", k, v)
+			if k == versioningModeLabel {
+				mode := ParseVersioningMode(v)
+				if mode == nil {
+					fmt.Printf("Failed to parse '%s' as a versioning mode\n", v)
+					continue
+				}
+
+				lc := LabeledContainer{
+					container,
+					*mode,
+				}
+
+				out = append(out, lc)
+				continue
+			}
+		}
+	}
+
+	return out
+}
+
+func (lc LabeledContainer) UpdateTo(cli *client.Client, tag Tag) error {
+	ctx := context.Background()
+
+	owner, repository, _ := lc.SplitImageParts()
+	image := combineImageParts(owner, repository, &tag.Name)
+	canonicalImage := fmt.Sprintf("docker.io/%s", image)
+	fmt.Printf("Pulling image \"%s\"\n", canonicalImage)
+
+	//containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
+	rc, err := cli.ImagePull(ctx, canonicalImage, types.ImagePullOptions{})
+	if err != nil {
+		return err
+	}
+
+	// TODO: does it still pull the image if i just close the reader?
+	err = rc.Close()
+	if err != nil {
+		return err
+	}
+
+	if len(lc.Container.Names) != 1 {
+		return errors.New("containers with more (or fewer) than 1 name are not supported")
+	}
+	name := lc.Container.Names[0]
+	tmpOldName := fmt.Sprintf("%s.lb.old", name)
+
+	fmt.Printf("Stopping container %s\n", lc.Container.ID)
+	// TODO: hopefully this is blocking
+	err = cli.ContainerStop(ctx, lc.Container.ID, nil)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Renaming container %s\n", lc.Container.ID)
+	err = cli.ContainerRename(ctx, lc.Container.ID, tmpOldName)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Creating new container\n")
+	body, err := cli.ContainerCreate(ctx, &container.Config{
+		Image: image,
+		//Cmd: []string{"echo", "hello world"},
+		Labels: lc.Container.Labels,
+		Tty: false,
+	}, &container.HostConfig{
+		VolumesFrom: []string{tmpOldName},
+	}, &network.NetworkingConfig{
+		EndpointsConfig: lc.Container.NetworkSettings.Networks,
+	}, name)
+
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Starting new container id: %s\n", body.ID)
+	err = cli.ContainerStart(ctx, body.ID, types.ContainerStartOptions{})
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Removing old container\n")
+	err = cli.ContainerRemove(ctx, tmpOldName, types.ContainerRemoveOptions{
+		RemoveVolumes: false,
+		RemoveLinks:   false,
+		Force:         false,
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}