From 54d903755daaa7204941e6314e36978653f82086 Mon Sep 17 00:00:00 2001
From: Michal Pristas <michal.pristas@gmail.com>
Date: Tue, 8 Sep 2020 10:02:55 +0200
Subject: [PATCH] placeholders

---
 .../application/handler_action_upgrade.go     | 52 ++++++++++++++-----
 .../pkg/agent/application/managed_mode.go     |  9 ++--
 2 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/x-pack/elastic-agent/pkg/agent/application/handler_action_upgrade.go b/x-pack/elastic-agent/pkg/agent/application/handler_action_upgrade.go
index 67942566f0e3..4979f1ad6638 100644
--- a/x-pack/elastic-agent/pkg/agent/application/handler_action_upgrade.go
+++ b/x-pack/elastic-agent/pkg/agent/application/handler_action_upgrade.go
@@ -23,12 +23,9 @@ const (
 // After running Upgrade agent should download its own version specified by action
 // from repository specified by fleet.
 type handlerUpgrade struct {
-	settings    *artifact.Config
-	log         *logger.Logger
-	emitter     emitterFunc
-	dispatcher  programsDispatcher
-	closers     []context.CancelFunc
-	actionStore *actionStore
+	settings *artifact.Config
+	log      *logger.Logger
+	closers  []context.CancelFunc
 }
 
 func (h *handlerUpgrade) Handle(ctx context.Context, a action, acker fleetAcker) error {
@@ -38,20 +35,29 @@ func (h *handlerUpgrade) Handle(ctx context.Context, a action, acker fleetAcker)
 		return fmt.Errorf("invalid type, expected ActionUpgrade and received %T", a)
 	}
 
-	// download artifact
-	_, err := h.downloadArtifact(ctx, action)
+	archivePath, err := h.downloadArtifact(ctx, action)
 	if err != nil {
 		return err
 	}
 
-	// TODO: unpack correctly, skip root (symlink, config...) unpack data/*
-	// TODO: change symlink
-	// TODO: mark update happened so we can handle grace period
-	// TODO: reexec
-	return nil
+	newHash, err := h.untar(ctx, action, archivePath)
+	if err != nil {
+		return err
+	}
+
+	if err := h.changeSymlink(ctx, action, newHash); err != nil {
+		return err
+	}
+
+	if err := h.markUpgrade(ctx, action); err != nil {
+		return err
+	}
+
+	return h.reexec(ctx, action)
 }
 
 func (h *handlerUpgrade) downloadArtifact(ctx context.Context, action *fleetapi.ActionUpgrade) (string, error) {
+	// do not update source config
 	settings := *h.settings
 	if action.SourceURI != "" {
 		settings.SourceURI = action.SourceURI
@@ -78,3 +84,23 @@ func (h *handlerUpgrade) downloadArtifact(ctx context.Context, action *fleetapi.
 
 	return path, nil
 }
+
+// untar unpacks archive correctly, skips root (symlink, config...) unpacks data/*
+func (h *handlerUpgrade) untar(ctx context.Context, action *fleetapi.ActionUpgrade, archivePath string) (string, error) {
+	return "", errors.New("not yet implemented")
+}
+
+// changeSymlink changes root symlink so it points to updated version
+func (h *handlerUpgrade) changeSymlink(ctx context.Context, action *fleetapi.ActionUpgrade, newHash string) error {
+	return errors.New("not yet implemented")
+}
+
+// markUpgrade marks update happened so we can handle grace period
+func (h *handlerUpgrade) markUpgrade(ctx context.Context, action *fleetapi.ActionUpgrade) error {
+	return errors.New("not yet implemented")
+}
+
+// reexec restarts agent so new version is run
+func (h *handlerUpgrade) reexec(ctx context.Context, action *fleetapi.ActionUpgrade) error {
+	return errors.New("not yet implemented")
+}
diff --git a/x-pack/elastic-agent/pkg/agent/application/managed_mode.go b/x-pack/elastic-agent/pkg/agent/application/managed_mode.go
index 2b49feddb3ad..2cd8ac2c76c1 100644
--- a/x-pack/elastic-agent/pkg/agent/application/managed_mode.go
+++ b/x-pack/elastic-agent/pkg/agent/application/managed_mode.go
@@ -209,12 +209,9 @@ func newManaged(
 	actionDispatcher.MustRegister(
 		&fleetapi.ActionUpgrade{},
 		&handlerUpgrade{
-			settings:    cfg.Settings.DownloadConfig,
-			log:         log,
-			emitter:     emit,
-			dispatcher:  router,
-			closers:     []context.CancelFunc{managedApplication.cancelCtxFn},
-			actionStore: actionStore,
+			settings: cfg.Settings.DownloadConfig,
+			log:      log,
+			closers:  []context.CancelFunc{managedApplication.cancelCtxFn},
 		},
 	)