Allow use of bash as a script interpreter

For #24470.

changes/24470-bash

@@ -0,0 +1 @@
+* Added bash interpreter support for script execution

cmd/fleetctl/scripts_test.go

@@ -112,12 +112,12 @@ hello world
 		{
 			name:         "invalid hashbang",
 			scriptPath:   func() string { return writeTmpScriptContents(t, "#! /foo/bar", ".sh") },
-			expectErrMsg: `Interpreter not supported. Shell scripts must run in "#!/bin/sh" or "#!/bin/zsh."`,
+			expectErrMsg: `Interpreter not supported. Shell scripts must run in "#!/bin/sh", "#!/bin/bash", or "#!/bin/zsh."`,
 		},
 		{
 			name:         "unsupported hashbang",
 			scriptPath:   func() string { return writeTmpScriptContents(t, "#!/bin/ksh", ".sh") },
-			expectErrMsg: `Interpreter not supported. Shell scripts must run in "#!/bin/sh" or "#!/bin/zsh."`,
+			expectErrMsg: `Interpreter not supported. Shell scripts must run in "#!/bin/sh", "#!/bin/bash", or "#!/bin/zsh."`,
 		},
 		{
 			name:       "posix shell hashbang",

frontend/pages/ManageControlsPage/Scripts/components/ScriptUploader/ScriptUploader.tsx

@@ -45,7 +45,7 @@ const ScriptPackageUploader = ({
       className={baseClass}
       graphicName={["file-sh", "file-ps1"]}
       message="Shell (.sh) for macOS and Linux or PowerShell (.ps1) for Windows"
-      additionalInfo="Script will run with “#!/bin/sh” or “#!/bin/zsh” on macOS and Linux."
+      additionalInfo="Script will run with “#!/bin/sh”, “#!/bin/zsh”, or “#!/bin/bash” on macOS and Linux."
       accept=".sh,.ps1"
       onFileUpload={onUploadFile}
       isLoading={showLoading}

orbit/pkg/scripts/exec_nonwindows_test.go

@@ -19,8 +19,10 @@ import (
 
 func TestExecCmdNonWindows(t *testing.T) {
 	zshPath := "/bin/zsh"
+	bashPath := "/bin/bash"
 	if runtime.GOOS == "linux" {
 		zshPath = "/usr/bin/zsh"
+		bashPath = "/usr/bin/bash"
 	}
 
 	tests := []struct {
@@ -40,6 +42,11 @@ func TestExecCmdNonWindows(t *testing.T) {
 			contents: "#!/bin/sh\n[ -z \"$ZSH_VERSION\" ] && echo 1",
 			output:   "1",
 		},
+		{
+			name:     "bash shebang",
+			contents: "#!" + bashPath + "\n[ -z \"$ZSH_VERSION\" ] && echo 1",
+			output:   "1",
+		},
 		{
 			name:     "zsh shebang",
 			contents: "#!" + zshPath + "\n[ -n \"$ZSH_VERSION\" ] && echo 1",

server/fleet/scripts.go

@@ -317,8 +317,8 @@ const (
 
 // anchored, so that it matches to the end of the line
 var (
-	scriptHashbangValidation  = regexp.MustCompile(`^#!\s*(:?/usr)?/bin/z?sh(?:\s*|\s+.*)$`)
-	ErrUnsupportedInterpreter = errors.New(`Interpreter not supported. Shell scripts must run in "#!/bin/sh" or "#!/bin/zsh."`)
+	scriptHashbangValidation  = regexp.MustCompile(`^#!\s*(:?/usr)?/bin/(ba|z)?sh(?:\s*|\s+.*)$`)
+	ErrUnsupportedInterpreter = errors.New(`Interpreter not supported. Shell scripts must run in "#!/bin/sh", "#!/bin/bash", or "#!/bin/zsh."`)
 )
 
 // ValidateShebang validates if we support a script, and whether we
@@ -327,7 +327,7 @@ func ValidateShebang(s string) (directExecute bool, err error) {
 	if strings.HasPrefix(s, "#!") {
 		// read the first line in a portable way
 		s := bufio.NewScanner(strings.NewReader(s))
-		// if a hashbang is present, it can only be `/bin/sh` or `(/usr)/bin/zsh` for now
+		// if a hashbang is present, it can only be `(/usr)/bin/sh`, `(/usr)/bin/bash`, `(/usr)/bin/zsh` for now
 		if s.Scan() && !scriptHashbangValidation.MatchString(s.Text()) {
 			return false, ErrUnsupportedInterpreter
 		}

server/fleet/scripts_test.go

@@ -81,6 +81,11 @@ func TestValidateShebang(t *testing.T) {
 			contents:      "#!/bin/zsh\necho hi",
 			directExecute: true,
 		},
+		{
+			name:          "bash shebang",
+			contents:      "#!/bin/bash\necho hi",
+			directExecute: true,
+		},
 		{
 			name:          "zsh shebang with args",
 			contents:      "#!/bin/zsh -x\necho hi",

server/service/scripts_test.go

@@ -313,12 +313,15 @@ func TestHostRunScript(t *testing.T) {
 			{"invalid utf8", "\xff\xfa", "Wrong data format."},
 			{"valid without hashbang", "echo 'a'", ""},
 			{"valid with posix hashbang", "#!/bin/sh\necho 'a'", ""},
+			{"valid with usr bash hashbang", "#!/usr/bin/bash\necho 'a'", ""},
+			{"valid with bash hashbang", "#!/bin/bash\necho 'a'", ""},
+			{"valid with bash hashbang and arguments", "#!/bin/bash -x\necho 'a'", ""},
 			{"valid with usr zsh hashbang", "#!/usr/bin/zsh\necho 'a'", ""},
 			{"valid with zsh hashbang", "#!/bin/zsh\necho 'a'", ""},
 			{"valid with zsh hashbang and arguments", "#!/bin/zsh -x\necho 'a'", ""},
 			{"valid with hashbang and spacing", "#! /bin/sh  \necho 'a'", ""},
 			{"valid with hashbang and Windows newline", "#! /bin/sh  \r\necho 'a'", ""},
-			{"invalid hashbang", "#!/bin/bash\necho 'a'", "Interpreter not supported."},
+			{"invalid hashbang", "#!/bin/ksh\necho 'a'", "Interpreter not supported."},
 		}
 
 		ctx = viewer.NewContext(ctx, viewer.Viewer{User: test.UserAdmin})