replace FAILED deployments with `helm upgrade --install --force`

When using `helm upgrade --install`, if the first release fails, Helm will respond with an error saying that it cannot upgrade from an unknown state.

With this feature, `helm upgrade --install --force` automates the same process as `helm delete && helm install --replace`. It will mark the previous release as DELETED, delete any existing resources inside Kubernetes, then replace it as if it was a fresh install. It will then mark the FAILED release as SUPERSEDED.

pkg/storage/storage.go

@@ -129,6 +129,10 @@ func (s *Storage) Deployed(name string) (*rspb.Release, error) {
 		return nil, err
 	}
 
+	if len(ls) == 0 {
+		return nil, fmt.Errorf("%q has no deployed releases", name)
+	}
+
 	return ls[0], err
 }
 

pkg/tiller/release_update.go

@@ -18,6 +18,7 @@ package tiller
 
 import (
 	"fmt"
+	"strings"
 
 	ctx "golang.org/x/net/context"
 
@@ -37,6 +38,10 @@ func (s *ReleaseServer) UpdateRelease(c ctx.Context, req *services.UpdateRelease
 	s.Log("preparing update for %s", req.Name)
 	currentRelease, updatedRelease, err := s.prepareUpdate(req)
 	if err != nil {
+		if req.Force {
+			// Use the --force, Luke.
+			return s.performUpdateForce(req)
+		}
 		return nil, err
 	}
 
@@ -137,6 +142,113 @@ func (s *ReleaseServer) prepareUpdate(req *services.UpdateReleaseRequest) (*rele
 	return currentRelease, updatedRelease, err
 }
 
+// performUpdateForce performs the same action as a `helm delete && helm install --replace`.
+func (s *ReleaseServer) performUpdateForce(req *services.UpdateReleaseRequest) (*services.UpdateReleaseResponse, error) {
+	// find the last release with the given name
+	oldRelease, err := s.env.Releases.Last(req.Name)
+	if err != nil {
+		return nil, err
+	}
+
+	newRelease, err := s.prepareRelease(&services.InstallReleaseRequest{
+		Chart:        req.Chart,
+		Values:       req.Values,
+		DryRun:       req.DryRun,
+		Name:         req.Name,
+		DisableHooks: req.DisableHooks,
+		Namespace:    oldRelease.Namespace,
+		ReuseName:    true,
+		Timeout:      req.Timeout,
+		Wait:         req.Wait,
+	})
+	res := &services.UpdateReleaseResponse{Release: newRelease}
+	if err != nil {
+		s.Log("failed update prepare step: %s", err)
+		// On dry run, append the manifest contents to a failed release. This is
+		// a stop-gap until we can revisit an error backchannel post-2.0.
+		if req.DryRun && strings.HasPrefix(err.Error(), "YAML parse error") {
+			err = fmt.Errorf("%s\n%s", err, newRelease.Manifest)
+		}
+		return res, err
+	}
+
+	// From here on out, the release is considered to be in Status_DELETING or Status_DELETED
+	// state. There is no turning back.
+	oldRelease.Info.Status.Code = release.Status_DELETING
+	oldRelease.Info.Deleted = timeconv.Now()
+	oldRelease.Info.Description = "Deletion in progress (or silently failed)"
+	s.recordRelease(oldRelease, true)
+
+	// pre-delete hooks
+	if !req.DisableHooks {
+		if err := s.execHook(oldRelease.Hooks, oldRelease.Name, oldRelease.Namespace, hooks.PreDelete, req.Timeout); err != nil {
+			return res, err
+		}
+	} else {
+		s.Log("hooks disabled for %s", req.Name)
+	}
+
+	// delete manifests from the old release
+	_, errs := s.ReleaseModule.Delete(oldRelease, nil, s.env)
+
+	oldRelease.Info.Status.Code = release.Status_DELETED
+	oldRelease.Info.Description = "Deletion complete"
+	s.recordRelease(oldRelease, true)
+
+	if len(errs) > 0 {
+		es := make([]string, 0, len(errs))
+		for _, e := range errs {
+			s.Log("error: %v", e)
+			es = append(es, e.Error())
+		}
+		return res, fmt.Errorf("Upgrade --force successfully deleted the previous release, but encountered %d error(s) and cannot continue: %s", len(es), strings.Join(es, "; "))
+	}
+
+	// post-delete hooks
+	if !req.DisableHooks {
+		if err := s.execHook(oldRelease.Hooks, oldRelease.Name, oldRelease.Namespace, hooks.PostDelete, req.Timeout); err != nil {
+			return res, err
+		}
+	}
+
+	// pre-install hooks
+	if !req.DisableHooks {
+		if err := s.execHook(newRelease.Hooks, newRelease.Name, newRelease.Namespace, hooks.PreInstall, req.Timeout); err != nil {
+			return res, err
+		}
+	}
+
+	// update new release with next revision number so as to append to the old release's history
+	newRelease.Version = oldRelease.Version + 1
+	s.recordRelease(newRelease, false)
+	if err := s.ReleaseModule.Update(oldRelease, newRelease, req, s.env); err != nil {
+		msg := fmt.Sprintf("Upgrade %q failed: %s", newRelease.Name, err)
+		s.Log("warning: %s", msg)
+		newRelease.Info.Status.Code = release.Status_FAILED
+		newRelease.Info.Description = msg
+		s.recordRelease(newRelease, true)
+		return res, err
+	}
+
+	// post-install hooks
+	if !req.DisableHooks {
+		if err := s.execHook(newRelease.Hooks, newRelease.Name, newRelease.Namespace, hooks.PostInstall, req.Timeout); err != nil {
+			msg := fmt.Sprintf("Release %q failed post-install: %s", newRelease.Name, err)
+			s.Log("warning: %s", msg)
+			newRelease.Info.Status.Code = release.Status_FAILED
+			newRelease.Info.Description = msg
+			s.recordRelease(newRelease, true)
+			return res, err
+		}
+	}
+
+	newRelease.Info.Status.Code = release.Status_DEPLOYED
+	newRelease.Info.Description = "Upgrade complete"
+	s.recordRelease(newRelease, true)
+
+	return res, nil
+}
+
 func (s *ReleaseServer) performUpdate(originalRelease, updatedRelease *release.Release, req *services.UpdateReleaseRequest) (*services.UpdateReleaseResponse, error) {
 	res := &services.UpdateReleaseResponse{Release: updatedRelease}
 

pkg/tiller/release_update_test.go

@@ -225,9 +225,9 @@ func TestUpdateReleaseFailure(t *testing.T) {
 
 	compareStoredAndReturnedRelease(t, *rs, *res)
 
-	edesc := "Upgrade \"angry-panda\" failed: Failed update in kube client"
-	if got := res.Release.Info.Description; got != edesc {
-		t.Errorf("Expected description %q, got %q", edesc, got)
+	expectedDescription := "Upgrade \"angry-panda\" failed: Failed update in kube client"
+	if got := res.Release.Info.Description; got != expectedDescription {
+		t.Errorf("Expected description %q, got %q", expectedDescription, got)
 	}
 
 	oldRelease, err := rs.env.Releases.Get(rel.Name, rel.Version)
@@ -239,6 +239,50 @@ func TestUpdateReleaseFailure(t *testing.T) {
 	}
 }
 
+func TestUpdateReleaseFailure_Force(t *testing.T) {
+	c := helm.NewContext()
+	rs := rsFixture()
+	rel := namedReleaseStub("forceful-luke", release.Status_FAILED)
+	rs.env.Releases.Create(rel)
+	rs.Log = t.Logf
+
+	req := &services.UpdateReleaseRequest{
+		Name:         rel.Name,
+		DisableHooks: true,
+		Chart: &chart.Chart{
+			Metadata: &chart.Metadata{Name: "hello"},
+			Templates: []*chart.Template{
+				{Name: "templates/something", Data: []byte("text: 'Did you ever hear the tragedy of Darth Plagueis the Wise? I thought not. It’s not a story the Jedi would tell you. It’s a Sith legend. Darth Plagueis was a Dark Lord of the Sith, so powerful and so wise he could use the Force to influence the Midichlorians to create life... He had such a knowledge of the Dark Side that he could even keep the ones he cared about from dying. The Dark Side of the Force is a pathway to many abilities some consider to be unnatural. He became so powerful... The only thing he was afraid of was losing his power, which eventually, of course, he did. Unfortunately, he taught his apprentice everything he knew, then his apprentice killed him in his sleep. Ironic. He could save others from death, but not himself.'")},
+			},
+		},
+		Force: true,
+	}
+
+	res, err := rs.UpdateRelease(c, req)
+	if err != nil {
+		t.Errorf("Expected successful update, got %v", err)
+	}
+
+	if updatedStatus := res.Release.Info.Status.Code; updatedStatus != release.Status_DEPLOYED {
+		t.Errorf("Expected DEPLOYED release. Got %d", updatedStatus)
+	}
+
+	compareStoredAndReturnedRelease(t, *rs, *res)
+
+	expectedDescription := "Upgrade complete"
+	if got := res.Release.Info.Description; got != expectedDescription {
+		t.Errorf("Expected description %q, got %q", expectedDescription, got)
+	}
+
+	oldRelease, err := rs.env.Releases.Get(rel.Name, rel.Version)
+	if err != nil {
+		t.Errorf("Expected to be able to get previous release")
+	}
+	if oldStatus := oldRelease.Info.Status.Code; oldStatus != release.Status_DELETED {
+		t.Errorf("Expected Deleted status on previous Release version. Got %v", oldStatus)
+	}
+}
+
 func TestUpdateReleaseNoHooks(t *testing.T) {
 	c := helm.NewContext()
 	rs := rsFixture()