feat(*): add rollback to a release version

closes #1244

_proto/hapi/services/tiller.proto

@@ -183,7 +183,6 @@ message UpdateReleaseRequest {
 	hapi.chart.Config values = 3;
 	// dry_run, if true, will run through the release logic, but neither create
 	bool dry_run = 4;
-
 	// DisableHooks causes the server to skip running any hooks for the upgrade.
 	bool disable_hooks = 5;
 }
@@ -200,6 +199,8 @@ message RollbackReleaseRequest {
 	bool dry_run = 2;
 	// DisableHooks causes the server to skip running any hooks for the rollback
 	bool disable_hooks = 3;
+	// Version is the version of the release to deploy.
+	int32 version = 4;
 }
 
 // RollbackReleaseResponse is the response to an update request.

cmd/helm/rollback.go

@@ -26,12 +26,13 @@ import (
 )
 
 const rollbackDesc = `
-This command rolls back a release to the previous version.
+This command rolls back a release to the previous revision.
 The argument of the rollback command is the name of a release.
 `
 
 type rollbackCmd struct {
 	name         string
+	version      int32
 	dryRun       bool
 	disableHooks bool
 	out          io.Writer
@@ -46,7 +47,7 @@ func newRollbackCmd(c helm.Interface, out io.Writer) *cobra.Command {
 
 	cmd := &cobra.Command{
 		Use:               "rollback [RELEASE]",
-		Short:             "roll back a release to the previous version",
+		Short:             "roll back a release to a previous revision",
 		Long:              rollbackDesc,
 		PersistentPreRunE: setupConnection,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -60,13 +61,19 @@ func newRollbackCmd(c helm.Interface, out io.Writer) *cobra.Command {
 	}
 
 	f := cmd.Flags()
+	f.Int32Var(&rollback.version, "revision", 0, "revision to deploy")
 	f.BoolVar(&rollback.dryRun, "dry-run", false, "simulate a rollback")
 	f.BoolVar(&rollback.disableHooks, "no-hooks", false, "prevent hooks from running during rollback")
 	return cmd
 }
 
 func (r *rollbackCmd) run() error {
-	_, err := r.client.RollbackRelease(r.name, helm.RollbackDryRun(r.dryRun), helm.RollbackDisableHooks(r.disableHooks))
+	_, err := r.client.RollbackRelease(
+		r.name,
+		helm.RollbackDryRun(r.dryRun),
+		helm.RollbackDisableHooks(r.disableHooks),
+		helm.RollbackVersion(r.version),
+	)
 	if err != nil {
 		return prettyError(err)
 	}

cmd/helm/rollback_test.go

@@ -29,7 +29,12 @@ func TestRollbackCmd(t *testing.T) {
 		{
 			name:     "rollback a release",
 			args:     []string{"funny-honey"},
-			resp:     nil,
+			flags:    []string{"revision", "1"},
+			expected: "Rollback was a success! Happy Helming!",
+		},
+		{
+			name:     "rollback a release without version",
+			args:     []string{"funny-honey"},
 			expected: "Rollback was a success! Happy Helming!",
 		},
 	}

cmd/tiller/release_server.go

@@ -461,7 +461,17 @@ func (s *releaseServer) prepareRollback(req *services.RollbackReleaseRequest) (*
 		return nil, nil, err
 	}
 
-	previousRelease, err := s.env.Releases.Get(req.Name, currentRelease.Version-1)
+	v := req.Version
+	if v == 0 {
+		v = currentRelease.Version - 1
+	}
+	if v < 1 {
+		return nil, nil, errors.New("cannot rollback to version < 1")
+	}
+
+	log.Printf("rolling back %s to version %d", req.Name, v)
+
+	previousRelease, err := s.env.Releases.Get(req.Name, v)
 	if err != nil {
 		return nil, nil, err
 	}

cmd/tiller/release_server_test.go

@@ -664,6 +664,27 @@ func TestRollbackReleaseNoHooks(t *testing.T) {
 	}
 }
 
+func TestRollbackWithReleaseVersion(t *testing.T) {
+	c := helm.NewContext()
+	rs := rsFixture()
+	rel := releaseStub()
+	rs.env.Releases.Create(rel)
+	upgradedRel := upgradeReleaseVersion(rel)
+	rs.env.Releases.Update(rel)
+	rs.env.Releases.Create(upgradedRel)
+
+	req := &services.RollbackReleaseRequest{
+		Name:         rel.Name,
+		DisableHooks: true,
+		Version:      1,
+	}
+
+	_, err := rs.RollbackRelease(c, req)
+	if err != nil {
+		t.Fatalf("Failed rollback: %s", err)
+	}
+}
+
 func TestRollbackRelease(t *testing.T) {
 	c := helm.NewContext()
 	rs := rsFixture()

pkg/helm/option.go

@@ -196,6 +196,13 @@ func RollbackDryRun(dry bool) RollbackOption {
 	}
 }
 
+// RollbackVersion sets the version of the release to deploy.
+func RollbackVersion(ver int32) RollbackOption {
+	return func(opts *options) {
+		opts.rollbackReq.Version = ver
+	}
+}
+
 // UpgradeDisableHooks will disable hooks for an upgrade operation.
 func UpgradeDisableHooks(disable bool) UpdateOption {
 	return func(opts *options) {
@@ -333,7 +340,7 @@ func (o *options) rpcRollbackRelease(rlsName string, rlc rls.ReleaseServiceClien
 	o.rollbackReq.DryRun = o.dryRun
 	o.rollbackReq.Name = rlsName
 
-	return rlc.RollbackRelease(context.TODO(), &o.rollbackReq)
+	return rlc.RollbackRelease(NewContext(), &o.rollbackReq)
 }
 
 // Executes tiller.GetReleaseStatus RPC.