Add the option to specify an alternative helm binary (#181)

`helm` may not be version compatible. Add an option to specify an alternative `helm` command on runtime, possibly according to the version of tiller running on your cluster.

helmexec/exec.go

@@ -11,6 +11,7 @@ const (
 )
 
 type execer struct {
+	helmBinary  string
 	runner      Runner
 	writer      io.Writer
 	kubeContext string
@@ -20,6 +21,7 @@ type execer struct {
 // New for running helm commands
 func New(writer io.Writer, kubeContext string) *execer {
 	return &execer{
+		helmBinary:  command,
 		writer:      writer,
 		kubeContext: kubeContext,
 		runner:      &ShellRunner{},
@@ -30,6 +32,10 @@ func (helm *execer) SetExtraArgs(args ...string) {
 	helm.extra = args
 }
 
+func (helm *execer) SetHelmBinary(bin string) {
+	helm.helmBinary = bin
+}
+
 func (helm *execer) AddRepo(name, repository, certfile, keyfile, username, password string) error {
 	var args []string
 	args = append(args, "repo", "add", name, repository)
@@ -114,8 +120,8 @@ func (helm *execer) exec(args ...string) ([]byte, error) {
 	if helm.kubeContext != "" {
 		cmdargs = append(cmdargs, "--kube-context", helm.kubeContext)
 	}
-	helm.write([]byte(fmt.Sprintf("exec: helm %s\n", strings.Join(cmdargs, " "))))
+	helm.write([]byte(fmt.Sprintf("exec: %s %s\n", helm.helmBinary, strings.Join(cmdargs, " "))))
-	return helm.runner.Execute(command, cmdargs)
+	return helm.runner.Execute(helm.helmBinary, cmdargs)
 }
 
 func (helm *execer) write(out []byte) {

helmexec/exec_test.go

@@ -56,6 +56,17 @@ func Test_SetExtraArgs(t *testing.T) {
 	}
 }
 
+func Test_SetHelmBinary(t *testing.T) {
+	helm := New(new(bytes.Buffer), "dev")
+	if helm.helmBinary != "helm" {
+		t.Error("helmexec.command - default command is not helm")
+	}
+	helm.SetHelmBinary("foo")
+	if helm.helmBinary != "foo" {
+		t.Errorf("helmexec.SetHelmBinary() - actual = %s expect = foo", helm.helmBinary)
+	}
+}
+
 func Test_AddRepo(t *testing.T) {
 	var buffer bytes.Buffer
 	helm := MockExecer(&buffer, "dev")
@@ -237,6 +248,15 @@ func Test_exec(t *testing.T) {
 	if buffer.String() != expected {
 		t.Errorf("helmexec.exec()\nactual = %v\nexpect = %v", buffer.String(), expected)
 	}
+
+	buffer.Reset()
+	helm = MockExecer(&buffer, "")
+	helm.SetHelmBinary("overwritten")
+	helm.exec("version")
+	expected = "exec: overwritten version\n"
+	if buffer.String() != expected {
+		t.Errorf("helmexec.exec()\nactual = %v\nexpect = %v", buffer.String(), expected)
+	}
 }
 
 func Test_Lint(t *testing.T) {

helmexec/helmexec.go

@@ -3,6 +3,7 @@ package helmexec
 // Interface for executing helm commands
 type Interface interface {
 	SetExtraArgs(args ...string)
+	SetHelmBinary(bin string)
 
 	AddRepo(name, repository, certfile, keyfile, username, password string) error
 	UpdateRepo() error

main.go

@@ -31,6 +31,10 @@ func main() {
 	app.Usage = ""
 	app.Version = Version
 	app.Flags = []cli.Flag{
+		cli.StringFlag{
+			Name:  "helm-binary, b",
+			Usage: "path to helm binary",
+		},
 		cli.StringFlag{
 			Name:  "file, f",
 			Value: DefaultHelmfile,
@@ -74,6 +78,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					return state.SyncRepos(helm)
 				})
@@ -104,6 +111,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					values := c.StringSlice("values")
 					workers := c.Int("concurrency")
@@ -141,6 +151,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					if c.Bool("sync-repos") {
 						if errs := state.SyncRepos(helm); errs != nil && len(errs) > 0 {
@@ -180,6 +193,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(strings.Split(args, " ")...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					values := c.StringSlice("values")
 					workers := c.Int("concurrency")
@@ -221,6 +237,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					values := c.StringSlice("values")
 					workers := c.Int("concurrency")
@@ -252,6 +271,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					return state.ReleaseStatuses(helm, workers)
 				})
@@ -302,6 +324,9 @@ func main() {
 					if len(args) > 0 {
 						helm.SetExtraArgs(args...)
 					}
+					if c.String("helm-binary") != "" {
+						helm.SetHelmBinary(c.String("helm-binary"))
+					}
 
 					return state.TestReleases(helm, cleanup, timeout)
 				})

state/state_test.go

@@ -521,6 +521,9 @@ func (helm *mockHelmExec) UpdateDeps(chart string) error {
 func (helm *mockHelmExec) SetExtraArgs(args ...string) {
 	return
 }
+func (helm *mockHelmExec) SetHelmBinary(bin string) {
+	return
+}
 func (helm *mockHelmExec) AddRepo(name, repository, certfile, keyfile, username, password string) error {
 	helm.repo = []string{name, repository, certfile, keyfile, username, password}
 	return nil