Change renaming behaviour

Create new container with name *.lb.new and then rename it instead of
renaming old container first

.gitignore

@@ -0,0 +1 @@
+.idea

Dockerfile

@@ -11,7 +11,7 @@ RUN go mod download
 
 # Copy source and build app
 COPY . /app
-RUN go build .
+RUN go build hulthe.net/lookbuilding/cmd/lookbuilding
 
 FROM alpine
 

README.md

@@ -1,6 +1,4 @@
 # lookbuilding
-_WIP_
-
 Scuffed lookalike of watchtower
 
 This project will, when triggered by an http request, scan the

cmd/lookbuilding/main.go

@@ -12,6 +12,8 @@ import (
 const EnvAddr = "LOOKBUILDING_ADDR"
 
 func main() {
+	//l.Logger.Level = logrus.DebugLevel
+
 	addr, isPresent := os.LookupEnv(EnvAddr)
 	if !isPresent {
 		addr = "0.0.0.0:8000"
@@ -22,8 +24,10 @@ func main() {
 		fmt.Fprintf(w, "OK")
 	})
 
-	fs := http.FileServer(http.Dir("static/"))
-	http.Handle("/static/", http.StripPrefix("/static/", fs))
+	http.HandleFunc("/healthcheck", func(w http.ResponseWriter, r *http.Request) {
+		// TODO: if the last scan errored, this should not return OK
+		fmt.Fprintf(w, "OK")
+	})
 
 	l.Logger.Infof(`listening on %s`, addr)
 

internal/pkg/docker/helpers.go

@@ -42,7 +42,6 @@ func (lc LabeledContainer) GetName() string {
 	}
 }
 
-
 func CombineImageParts(owner *string, repository string, tag *string) string {
 	image := repository
 	if owner != nil {

internal/pkg/docker/mode.go

@@ -0,0 +1,126 @@
+package docker
+
+import (
+	"sort"
+
+	l "hulthe.net/lookbuilding/internal/pkg/logging"
+	"hulthe.net/lookbuilding/internal/pkg/registry"
+	"hulthe.net/lookbuilding/internal/pkg/semver"
+)
+
+const VersioningModeLabel = "lookbuilding.mode"
+
+type VersioningMode interface {
+	Label() string
+	ShouldUpdate(container LabeledContainer, availableTags []registry.Tag) *registry.Tag
+}
+
+type SameTag struct{}
+type SemVerMajor struct{}
+type SemVerMinor struct{}
+type SemVerPatch struct{}
+
+var (
+	AllModes = [...]VersioningMode{
+		SameTag{},
+		SemVerMajor{},
+		SemVerMinor{},
+		SemVerPatch{},
+	}
+)
+
+func (SameTag) Label() string { return "same_tag" }
+func (SameTag) ShouldUpdate(container LabeledContainer, availableTags []registry.Tag) *registry.Tag {
+	_, _, currentTag := container.SplitImageParts()
+	if currentTag == nil {
+		l.Logger.Errorf("container %s has no tag, won't try to update", container.GetName())
+		return nil
+	}
+
+	for _, tag := range availableTags {
+		if tag.Name == *currentTag {
+			remoteDigest, err := tag.GetDigest()
+			if err != nil {
+				l.Logger.Errorf("failed to get digest for tag %s", tag.Name)
+				l.Logger.Error(err)
+			}
+
+			l.Logger.Debug(remoteDigest.String(), container.ImageDigest)
+			if container.ImageDigest != remoteDigest {
+				return &tag
+			}
+			return nil
+		}
+	}
+
+	return nil
+}
+
+func semVerShouldUpdate(container LabeledContainer, availableTags []registry.Tag, isValid func(current, available semver.Tag) bool) *registry.Tag {
+	_, _, currentTag := container.SplitImageParts()
+	if currentTag == nil {
+		l.Logger.Errorf("container %s has no tag, won't try to update", container.GetName())
+		return nil
+	}
+
+	currentSemVer := semver.ParseTagAsSemVer(*currentTag)
+	if currentSemVer == nil {
+		return nil
+	}
+
+	semverTags := make([]registry.Tag, 0)
+
+	for _, tag := range availableTags {
+		if tag.SemVer != nil && isValid(*currentSemVer, *tag.SemVer) {
+			semverTags = append(semverTags, tag)
+		}
+	}
+
+	if len(semverTags) == 0 {
+		return nil
+	}
+
+	sort.Slice(semverTags, func(i, j int) bool {
+		a := semverTags[i].SemVer.Version
+		b := semverTags[j].SemVer.Version
+		return b.LessThan(a)
+	})
+
+	return &semverTags[0]
+}
+
+func (SemVerMajor) Label() string { return "semver_major" }
+func (SemVerMajor) ShouldUpdate(container LabeledContainer, availableTags []registry.Tag) *registry.Tag {
+	return semVerShouldUpdate(container, availableTags, func(current, available semver.Tag) bool {
+		// The new version should be greater
+		return current.Version.LessThan(available.Version)
+	})
+}
+
+func (SemVerMinor) Label() string { return "semver_minor" }
+func (SemVerMinor) ShouldUpdate(container LabeledContainer, availableTags []registry.Tag) *registry.Tag {
+	return semVerShouldUpdate(container, availableTags, func(current, available semver.Tag) bool {
+		// The new version should be greater, but still the same major number
+		return current.Version.LessThan(available.Version) &&
+			current.Version.Major == available.Version.Major
+	})
+}
+
+func (SemVerPatch) Label() string { return "semver_patch" }
+func (SemVerPatch) ShouldUpdate(container LabeledContainer, availableTags []registry.Tag) *registry.Tag {
+	return semVerShouldUpdate(container, availableTags, func(current, available semver.Tag) bool {
+		// The new version should be greater, but still the same major & minor number
+		return current.Version.LessThan(available.Version) &&
+			current.Version.Major == available.Version.Major &&
+			current.Version.Minor == available.Version.Minor
+	})
+}
+
+func ParseMode(input string) *VersioningMode {
+	for _, mode := range AllModes {
+		if mode.Label() == input {
+			return &mode
+		}
+	}
+	return nil
+}

internal/pkg/docker/rpc.go

@@ -3,17 +3,19 @@ package docker
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	l "hulthe.net/lookbuilding/internal/pkg/logging"
 	"hulthe.net/lookbuilding/internal/pkg/registry"
-	"hulthe.net/lookbuilding/internal/pkg/versioning"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/network"
 	"github.com/docker/docker/client"
+	d "github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
 )
 
-func GetLabeledContainers(cli *client.Client) []LabeledContainer {
+func GetLabeledContainers(cli *client.Client) ([]LabeledContainer, error) {
 	out := make([]LabeledContainer, 0)
 
 	containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
@@ -23,19 +25,42 @@ func GetLabeledContainers(cli *client.Client) []LabeledContainer {
 
 	l.Logger.Infof("scanning running container labels")
 	for _, container := range containers {
-		l.Logger.Debugf("checking %s %s", container.ID[:10], container.Image)
-		for k, v := range container.Labels {
-			l.Logger.Debugf(`  - "%s": "%s"`, k, v)
-			if k == versioning.ModeLabel {
-				mode := versioning.ParseMode(v)
-				if mode == nil {
-					l.Logger.Errorf(`Failed to parse "%s" as a versioning mode`, v)
+		lc := LabeledContainer{Container: container}
+
+		if container.Image == container.ImageID {
+			l.Logger.Errorf("ignoring container %s which has an untagged image", lc.GetName())
 			continue
 		}
 
-				lc := LabeledContainer{
-					container,
-					*mode,
+		l.Logger.Debugf("checking %s %s", lc.GetName(), container.Image)
+		for k, v := range container.Labels {
+			l.Logger.Debugf(`  - "%s": "%s"`, k, v)
+
+			if k == VersioningModeLabel {
+				mode := ParseMode(v)
+				if mode == nil {
+					l.Logger.Errorf(`failed to parse "%s" as a versioning mode`, v)
+					continue
+				}
+				lc.Mode = *mode
+
+				inspect, _, err := cli.ImageInspectWithRaw(context.Background(), container.ImageID)
+				if err != nil {
+					return nil, errors.Wrapf(err, "failed to inspect container %s", lc.GetName())
+				}
+
+				if len(inspect.RepoDigests) >= 2 {
+					// TODO: find out if having more than one digest could break same_tag version mode
+					l.Logger.Warnf("unexpected: container %s had more than one RepoDigest", lc.GetName())
+				} else if len(inspect.RepoDigests) == 0 {
+					return nil, errors.Errorf("unexpected: container %s has no RepoDigests", lc.GetName())
+				}
+
+				imageDigest := inspect.RepoDigests[0]
+				atIndex := strings.Index(imageDigest, "@")
+				lc.ImageDigest, err = d.Parse(imageDigest[atIndex+1:])
+				if err != nil {
+					return nil, errors.Wrapf(err, "failed to parse image digest of running container %s", lc.GetName())
 				}
 
 				out = append(out, lc)
@@ -44,7 +69,7 @@ func GetLabeledContainers(cli *client.Client) []LabeledContainer {
 		}
 	}
 
-	return out
+	return out, nil
 }
 
 func (lc LabeledContainer) UpdateTo(cli *client.Client, tag registry.Tag) error {
@@ -55,63 +80,60 @@ func (lc LabeledContainer) UpdateTo(cli *client.Client, tag registry.Tag) error
 	canonicalImage := fmt.Sprintf("docker.io/%s", image)
 	l.Logger.Infof(`pulling image "%s"`, canonicalImage)
 
-	//containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
 	imageReader, err := cli.ImagePull(ctx, canonicalImage, types.ImagePullOptions{})
 	if err != nil {
-		return err
+		return errors.Wrapf(err, `failed to pull image "%s"`, canonicalImage)
 	}
 
-	defer imageReader.Close()
-
 	loadResponse, err := cli.ImageLoad(ctx, imageReader, false)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, `failed to load pulled image "%s"`, canonicalImage)
 	}
 
-	defer loadResponse.Body.Close()
+	err = loadResponse.Body.Close()
+	if err != nil {
+		return errors.Wrapf(err, `failed to close rpc response when loading image "%s"`, canonicalImage)
+	}
+	err = imageReader.Close()
+	if err != nil {
+		return errors.Wrapf(err, `failed to close rpc response when pulling image "%s"`, canonicalImage)
+	}
 
-	fmt.Printf("Stopping container %s\n", lc.Container.ID)
+	l.Logger.Infof("stopping container %s", lc.GetName())
 	err = cli.ContainerStop(ctx, lc.Container.ID, nil)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, `failed to stop container "%s"`, lc.GetName())
 	}
 
 	oldContainer, err := cli.ContainerInspect(ctx, lc.Container.ID)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, `failed to inspect container "%s"`, lc.GetName())
 	}
 
-	name := oldContainer.Name
-	tmpOldName := fmt.Sprintf("%s.lb.old", name)
+	tmpName := fmt.Sprintf("%s.lb.new", lc.GetName())
 
-	config := oldContainer.Config
+	config := *oldContainer.Config
 	config.Image = image
 
-	hostConfig := oldContainer.HostConfig
-	hostConfig.VolumesFrom = []string{tmpOldName}
+	hostConfig := *oldContainer.HostConfig
+	hostConfig.VolumesFrom = []string{lc.GetName()}
 
-	l.Logger.Infof(`renaming container %s`, lc.Container.ID)
-	err = cli.ContainerRename(ctx, lc.Container.ID, tmpOldName)
-	if err != nil {
-		return err
-	}
-
-	l.Logger.Infof("creating new container")
-	new, err := cli.ContainerCreate(ctx, oldContainer.Config, hostConfig, &network.NetworkingConfig{
+	l.Logger.Infof("creating new container %s", tmpName)
+	new, err := cli.ContainerCreate(ctx, &config, &hostConfig, &network.NetworkingConfig{
 		EndpointsConfig: oldContainer.NetworkSettings.Networks,
-	}, name)
+	}, tmpName)
 
 	if err != nil {
-		return err
+		return errors.Wrapf(err, `failed to create container for new version of %s`, image)
 	}
 
-	l.Logger.Infof("starting new container id: %s", new.ID)
+	l.Logger.Infof("starting new container %s with id %s", tmpName, new.ID)
 	err = cli.ContainerStart(ctx, new.ID, types.ContainerStartOptions{})
 	if err != nil {
 		return err
 	}
 
-	l.Logger.Infof("removing old container")
+	l.Logger.Infof("removing old container %s", lc.GetName())
 	err = cli.ContainerRemove(ctx, oldContainer.ID, types.ContainerRemoveOptions{
 		RemoveVolumes: false,
 		RemoveLinks:   false,
@@ -121,6 +143,11 @@ func (lc LabeledContainer) UpdateTo(cli *client.Client, tag registry.Tag) error
 		return err
 	}
 
+	l.Logger.Infof(`renaming container %s to %s`, tmpName, lc.GetName())
+	err = cli.ContainerRename(ctx, new.ID, lc.GetName())
+	if err != nil {
+		return errors.Wrapf(err, `failed to rename container "%s" to "%s"`, tmpName, lc.GetName())
+	}
+
 	return nil
 }
-

internal/pkg/docker/types.go

@@ -1,12 +1,12 @@
 package docker
 
 import (
-	"hulthe.net/lookbuilding/internal/pkg/versioning"
-
 	"github.com/docker/docker/api/types"
+	d "github.com/opencontainers/go-digest"
 )
 
 type LabeledContainer struct {
 	Container   types.Container
-	Mode      versioning.Mode
+	Mode        VersioningMode
+	ImageDigest d.Digest
 }

internal/pkg/registry/cache.go

@@ -1,10 +1,14 @@
 package registry
 
 import (
+	"fmt"
+	"net/http"
+
+	l "hulthe.net/lookbuilding/internal/pkg/logging"
 	"hulthe.net/lookbuilding/internal/pkg/semver"
 
 	"github.com/heroku/docker-registry-client/registry"
-	"github.com/opencontainers/go-digest"
+	d "github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 )
 
@@ -25,7 +29,7 @@ type digestReq struct {
 }
 
 type digestResp struct {
-	Data digest.Digest
+	Data  d.Digest
 	Error error
 }
 
@@ -33,7 +37,7 @@ type repoCache struct {
 	Tags []Tag
 
 	// Map tags to digests
-	Digests map[string]digest.Digest
+	Digests map[string]d.Digest
 }
 
 type cache struct {
@@ -44,12 +48,57 @@ type cache struct {
 func newCache(registry registry.Registry) cache {
 	tagListReq := make(chan tagListReq)
 	digestReq := make(chan digestReq)
+	cache := cache{
+		tagListReq,
+		digestReq,
+	}
 
 	store := map[string]repoCache{}
 
 	go func() {
 		for {
 			select {
+			case req := <-digestReq:
+				repo, isPresent := store[req.repository]
+				if !isPresent {
+					req.responder <- digestResp{Error: errors.Errorf(
+						`repo "%s" not present in cache, can't fetch digest'`, req.repository,
+					)}
+				}
+
+				digest, isPresent := repo.Digests[req.tag]
+				if isPresent {
+					req.responder <- digestResp{Data: digest}
+				} else {
+					url := fmt.Sprintf("%s/v2/%s/manifests/%s", registry.URL, req.repository, req.tag)
+					l.Logger.Infof("registry.manifest.head url=%s repository=%s reference=%s", url, req.repository, req.tag)
+
+					httpReq, _ := http.NewRequest("HEAD", url, nil)
+					httpReq.Header.Add("Accept", "application/vnd.docker.distribution.manifest.v2+json")
+					resp, err := registry.Client.Do(httpReq)
+					if resp != nil {
+						defer resp.Body.Close()
+					}
+					if err != nil {
+						req.responder <- digestResp{Error: errors.Wrapf(
+							err, "failed to get digest for repo=%s tag=%s", req.repository, req.tag,
+						)}
+					}
+					digest, err := d.Parse(resp.Header.Get("Docker-Content-Digest"))
+
+					/*
+						digest, err := registry.ManifestDigest(req.repository, req.tag)
+						if err != nil {
+							req.responder <- digestResp{Error: errors.Wrapf(
+									err, `failed to get digest for repo=%s tag=%s`, req.repository, req.tag,
+								)}
+						}
+					*/
+
+					repo.Digests[req.tag] = digest
+					req.responder <- digestResp{Data: digest}
+				}
+
 			case req := <-tagListReq:
 				repo, isPresent := store[req.repository]
 
@@ -73,48 +122,24 @@ func newCache(registry registry.Registry) cache {
 						tags = append(tags, Tag{
 							Name:       tagName,
 							SemVer:     semver.ParseTagAsSemVer(tagName),
+							repository: req.repository,
+							cache:      cache,
 						})
 					}
 
 					// store result in cache
 					store[req.repository] = repoCache{
 						Tags:    tags,
-						Digests: map[string]digest.Digest{},
+						Digests: map[string]d.Digest{},
 					}
 
 					req.responder <- tagListResp{
 						Data: tags,
 					}
 				}
-
-			case req := <-digestReq:
-				repo, isPresent := store[req.repository]
-				if !isPresent {
-					req.responder <- digestResp{Error: errors.Errorf(
-						`repo "%s" not present in cache, can't fetch digest'`, req.repository,
-					)}
-				}
-
-				digest, isPresent := repo.Digests[req.tag]
-				if isPresent {
-					req.responder <- digestResp{Data: digest}
-				} else {
-					digest, err := registry.ManifestDigest(req.repository, req.tag)
-					if err != nil {
-						req.responder <- digestResp{Error: errors.Wrapf(
-							err, `failed to get digest for repo=%s tag=%s`, req.repository, req.tag,
-						)}
-					}
-
-					repo.Digests[req.tag] = digest
-					req.responder <- digestResp{Data: digest}
-				}
 			}
 		}
 	}()
 
-	return cache {
-		tagListReq,
-		digestReq,
-	}
+	return cache
 }

internal/pkg/registry/client.go

@@ -23,7 +23,7 @@ type Client struct {
 
 func (tag Tag) GetDigest() (digest.Digest, error) {
 	responseCh := make(chan digestResp)
-	tag.cache.DigestReq <- digestReq{ tag.repository, tag.Name, responseCh	}
+	tag.cache.DigestReq <- digestReq{tag.repository, tag.Name, responseCh}
 	resp := <-responseCh
 	return resp.Data, resp.Error
 }
@@ -34,9 +34,8 @@ func (client Client) GetRepoTags(maybeOwner *string, repository string) ([]Tag,
 	}
 
 	responseCh := make(chan tagListResp)
-	client.cache.TagListReq <- tagListReq { repository, responseCh }
+	client.cache.TagListReq <- tagListReq{repository, responseCh}
 	resp := <-responseCh
-
 	return resp.Data, resp.Error
 }
 

internal/pkg/versioning/mode.go

@@ -1,99 +0,0 @@
-package versioning
-
-import (
-	"sort"
-
-	l "hulthe.net/lookbuilding/internal/pkg/logging"
-	"hulthe.net/lookbuilding/internal/pkg/registry"
-	"hulthe.net/lookbuilding/internal/pkg/semver"
-)
-
-const ModeLabel = "lookbuilding.mode"
-
-type Mode interface {
-	Label() string
-	ShouldUpdate(currentTag string, availableTags []registry.Tag) *registry.Tag
-}
-
-type SameTag struct{}
-type SemVerMajor struct{}
-type SemVerMinor struct{}
-type SemVerPatch struct{}
-
-var (
-	AllModes = [...]Mode{
-		SameTag{},
-		SemVerMajor{},
-		SemVerMinor{},
-		SemVerPatch{},
-	}
-)
-
-func (SameTag) Label() string { return "same_tag" }
-func (SameTag) ShouldUpdate(currentTag string, availableTags []registry.Tag) *registry.Tag {
-	l.Logger.Errorf("Not implemented: 'same_tag' versioning mode")
-	return nil // TODO: implement me
-}
-
-func semVerShouldUpdate(currentTag string, availableTags []registry.Tag, isValid func(current, available semver.Tag) bool) *registry.Tag {
-	currentSemVer := semver.ParseTagAsSemVer(currentTag)
-	if currentSemVer == nil {
-		return nil
-	}
-
-	semverTags := make([]registry.Tag, 0)
-
-	for _, tag := range availableTags {
-		if tag.SemVer != nil && isValid(*currentSemVer, *tag.SemVer) {
-			semverTags = append(semverTags, tag)
-		}
-	}
-
-	if len(semverTags) == 0 {
-		return nil
-	}
-
-	sort.Slice(semverTags, func(i, j int) bool {
-		a := semverTags[i].SemVer.Version
-		b := semverTags[j].SemVer.Version
-		return b.LessThan(a)
-	})
-
-	return &semverTags[0]
-}
-
-func (SemVerMajor) Label() string { return "semver_major" }
-func (SemVerMajor) ShouldUpdate(currentTag string, availableTags []registry.Tag) *registry.Tag {
-	return semVerShouldUpdate(currentTag, availableTags, func(current, available semver.Tag) bool {
-		// The new version should be greater
-		return current.Version.LessThan(available.Version)
-	})
-}
-
-func (SemVerMinor) Label() string { return "semver_minor" }
-func (SemVerMinor) ShouldUpdate(currentTag string, availableTags []registry.Tag) *registry.Tag {
-	return semVerShouldUpdate(currentTag, availableTags, func(current, available semver.Tag) bool {
-		// The new version should be greater, but still the same major number
-		return current.Version.LessThan(available.Version) &&
-			current.Version.Major == available.Version.Major
-	})
-}
-
-func (SemVerPatch) Label() string { return "semver_patch" }
-func (SemVerPatch) ShouldUpdate(currentTag string, availableTags []registry.Tag) *registry.Tag {
-	return semVerShouldUpdate(currentTag, availableTags, func(current, available semver.Tag) bool {
-		// The new version should be greater, but still the same major & minor number
-		return current.Version.LessThan(available.Version) &&
-			current.Version.Major == available.Version.Major &&
-			current.Version.Minor == available.Version.Minor
-	})
-}
-
-func ParseMode(input string) *Mode {
-	for _, mode := range AllModes {
-		if mode.Label() == input {
-			return &mode
-		}
-	}
-	return nil
-}

internal/pkg/worker/worker.go

@@ -64,7 +64,10 @@ func checkAndDoUpdate() {
 		panic(err)
 	}
 
-	labeledContainers := docker.GetLabeledContainers(cli)
+	labeledContainers, err := docker.GetLabeledContainers(cli)
+	if err != nil {
+		panic(err)
+	}
 
 	l.Logger.Infof("found %d valid containers", len(labeledContainers))
 
@@ -85,25 +88,24 @@ func checkAndDoUpdate() {
 			panic(err)
 		}
 
-		l.Logger.Infof(`tags in registry for "%s": %d`, name, len(repoTags))
+		l.Logger.Debugf(`tags in registry for "%s": %d`, name, len(repoTags))
 		for _, tag := range repoTags {
 			svt := semver.ParseTagAsSemVer(tag.Name)
-			l.Logger.Infof(`tag_name="%s" semver=%t`, tag.Name, svt != nil)
+			l.Logger.Debugf(`tag_name="%s" semver=%t`, tag.Name, svt != nil)
 		}
 
-		shouldUpdateTo := lc.Mode.ShouldUpdate(*tag, repoTags)
+		shouldUpdateTo := lc.Mode.ShouldUpdate(lc, repoTags)
 		if shouldUpdateTo != nil {
-			l.Logger.Infof(`updating %s from %s to: %s`, name, *tag, shouldUpdateTo.Name)
+			l.Logger.Infof(`updating %s from %s to %s`, name, *tag, shouldUpdateTo.Name)
 
-			go func() {
 			err = lc.UpdateTo(cli, *shouldUpdateTo)
 			if err != nil {
 				l.Logger.Error(err)
 			}
-			}()
 		} else {
 			l.Logger.Infof("no update available for container %s", name)
 		}
 	}
+
 	l.Logger.Infof("all done")
 }