provisioner/shell: inline_shebang for inline scripts

CHANGELOG.md

@@ -11,6 +11,10 @@ IMPROVEMENTS:
 
 * core: If SCP is not available, a more descriptive error message
   is shown telling the user. [GH-127]
+* shell: Scripts are now executed by default according to their shebang,
+  not with `/bin/sh`. [GH-105]
+* shell: You can specify what interpreter you want inline scripts to
+  run with `inline_shebang`.
 * virtualbox: Delete the packer-made SSH port forwarding prior to
   exporting the VM.
 

provisioner/shell/provisioner.go

@@ -25,6 +25,9 @@ type config struct {
 	// in the context of a single shell.
 	Inline []string
 
+	// The shebang value used when running inline scripts.
+	InlineShebang string `mapstructure:"inline_shebang"`
+
 	// The local path of the shell script to upload and execute.
 	Script string
 
@@ -69,6 +72,10 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 		p.config.Inline = nil
 	}
 
+	if p.config.InlineShebang == "" {
+		p.config.InlineShebang = "/bin/sh"
+	}
+
 	if p.config.RemotePath == "" {
 		p.config.RemotePath = DefaultRemotePath
 	}
@@ -136,6 +143,7 @@ func (p *Provisioner) Provision(ui packer.Ui, comm packer.Communicator) error {
 
 		// Write our contents to it
 		writer := bufio.NewWriter(tf)
+		writer.WriteString(fmt.Sprintf("#!%s\n", p.config.InlineShebang))
 		for _, command := range p.config.Inline {
 			if _, err := writer.WriteString(command + "\n"); err != nil {
 				return fmt.Errorf("Error preparing shell script: %s", err)

provisioner/shell/provisioner_test.go

@@ -35,6 +35,33 @@ func TestProvisionerPrepare_Defaults(t *testing.T) {
 	}
 }
 
+func TestProvisionerPrepare_InlineShebang(t *testing.T) {
+	config := testConfig()
+
+	delete(config, "inline_shebang")
+	p := new(Provisioner)
+	err := p.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+
+	if p.config.InlineShebang != "/bin/sh" {
+		t.Fatalf("bad value: %s", p.config.InlineShebang)
+	}
+
+	// Test with a good one
+	config["inline_shebang"] = "foo"
+	p = new(Provisioner)
+	err = p.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+
+	if p.config.InlineShebang != "foo" {
+		t.Fatalf("bad value: %s", p.config.InlineShebang)
+	}
+}
+
 func TestProvisionerPrepare_Script(t *testing.T) {
 	config := testConfig()
 	delete(config, "inline")