Add the ability to change user on *nix systems

Author: dylanhitt

command.go

@@ -47,25 +47,24 @@ type Command struct {
 //
 // Example:
 //
-//  env := map[string]string{"ENV": "VALUE"}
-//
+//	env := map[string]string{"ENV": "VALUE"}
 type EnvVars map[string]string
 
 // NewCommand creates a new command
 // You can add option with variadic option argument
 // Default timeout is set to 30 minutes
 //
 // Example:
-//      c := cmd.NewCommand("echo hello", function (c *Command) {
-//		    c.WorkingDir = "/tmp"
-//      })
-//      c.Execute()
 //
-// or you can use existing options functions
+//	     c := cmd.NewCommand("echo hello", function (c *Command) {
+//			    c.WorkingDir = "/tmp"
+//	     })
+//	     c.Execute()
 //
-//      c := cmd.NewCommand("echo hello", cmd.WithStandardStreams)
-//      c.Execute()
+// or you can use existing options functions
 //
+//	c := cmd.NewCommand("echo hello", cmd.WithStandardStreams)
+//	c.Execute()
 func NewCommand(cmd string, options ...func(*Command)) *Command {
 	c := &Command{
 		Command:  cmd,
@@ -90,12 +89,11 @@ func NewCommand(cmd string, options ...func(*Command)) *Command {
 //
 // Example:
 //
-//      c := cmd.NewCommand(
-//        "echo hello",
-//        cmd.WithCustomBaseCommand(exec.Command("/bin/bash", "-c")),
-//      )
-//      c.Execute()
-//
+//	c := cmd.NewCommand(
+//	  "echo hello",
+//	  cmd.WithCustomBaseCommand(exec.Command("/bin/bash", "-c")),
+//	)
+//	c.Execute()
 func WithCustomBaseCommand(baseCommand *exec.Cmd) func(c *Command) {
 	return func(c *Command) {
 		baseCommand.Args = append(baseCommand.Args, c.Command)
@@ -108,9 +106,8 @@ func WithCustomBaseCommand(baseCommand *exec.Cmd) func(c *Command) {
 //
 // Example:
 //
-//     c := cmd.NewCommand("echo hello", cmd.WithStandardStreams)
-//     c.Execute()
-//
+//	c := cmd.NewCommand("echo hello", cmd.WithStandardStreams)
+//	c.Execute()
 func WithStandardStreams(c *Command) {
 	c.StdoutWriter = io.MultiWriter(os.Stdout, &c.stdout, &c.combined)
 	c.StderrWriter = io.MultiWriter(os.Stderr, &c.stderr, &c.combined)
@@ -135,8 +132,8 @@ func WithCustomStderr(writers ...io.Writer) func(c *Command) {
 // WithTimeout sets the timeout of the command
 //
 // Example:
-//     cmd.NewCommand("sleep 10;", cmd.WithTimeout(500))
 //
+//	cmd.NewCommand("sleep 10;", cmd.WithTimeout(500))
 func WithTimeout(t time.Duration) func(c *Command) {
 	return func(c *Command) {
 		c.Timeout = t
@@ -201,13 +198,13 @@ func (c *Command) Combined() string {
 	return c.combined.String()
 }
 
-//ExitCode returns the exit code of the command
+// ExitCode returns the exit code of the command
 func (c *Command) ExitCode() int {
 	c.isExecuted("ExitCode")
 	return c.exitCode
 }
 
-//Executed returns if the command was already executed
+// Executed returns if the command was already executed
 func (c *Command) Executed() bool {
 	return c.executed
 }

command_darwin.go

@@ -2,9 +2,18 @@ package cmd
 
 import (
 	"os/exec"
+	"syscall"
 )
 
 func createBaseCommand(c *Command) *exec.Cmd {
 	cmd := exec.Command("/bin/sh", "-c", c.Command)
 	return cmd
 }
+
+func WithUser(credential syscall.Credential) func(c *Command) {
+	return func(c *Command) {
+		c.baseCommand.SysProcAttr = &syscall.SysProcAttr{
+			Credential: &credential,
+		}
+	}
+}

command_darwin_test.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"syscall"
 	"testing"
 	"time"
 
@@ -32,3 +33,13 @@ func TestCommand_WithValidTimeout(t *testing.T) {
 
 	assert.Nil(t, err)
 }
+
+// I really don't see the point of mocking this
+// as the stdlib does so already. So testing here
+// seems redundant. This simple check if we're compliant
+// with an api changes
+func TestCommand_WithUser(t *testing.T) {
+	cmd := NewCommand("echo hello", WithUser(syscall.Credential{}))
+	err := cmd.Execute()
+	assert.Error(t, err)
+}

command_linux.go

@@ -2,9 +2,18 @@ package cmd
 
 import (
 	"os/exec"
+	"syscall"
 )
 
 func createBaseCommand(c *Command) *exec.Cmd {
 	cmd := exec.Command("/bin/sh", "-c", c.Command)
 	return cmd
 }
+
+func WithUser(credential syscall.Credential) func(c *Command) {
+	return func(c *Command) {
+		c.baseCommand.SysProcAttr = &syscall.SysProcAttr{
+			Credential: &credential,
+		}
+	}
+}

command_linux_test.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+	"syscall"
 	"testing"
 	"time"
 
@@ -171,3 +172,10 @@ func TestCommand_WithCustomBaseCommand(t *testing.T) {
 	assert.NotEqual(t, "/bin/sh\n", cmd.Stdout())
 	assert.Equal(t, "/bin/bash\n", cmd.Stdout())
 }
+
+func TestCommand_WithUser(t *testing.T) {
+	cred := syscall.Credential{}
+	cmd := NewCommand("echo hello", WithUser(cred))
+	err := cmd.Execute()
+	assert.Error(t, err)
+}