Merge pull request #6878 from jvasallo/f-shell-local-specificos

feat: ability to specify runtime OSs where shell-local should run

common/shell-local/config.go

@@ -29,6 +29,9 @@ type Config struct {
 	// The shebang value used when running inline scripts.
 	InlineShebang string `mapstructure:"inline_shebang"`
 
+	// An array of multiple Runtime OSs to run on.
+	OnlyOn []string `mapstructure:"only_on"`
+
 	// The file extension to use for the file generated from the inline commands
 	TempfileExtension string `mapstructure:"tempfile_extension"`
 
@@ -159,6 +162,25 @@ func Validate(config *Config) error {
 				fmt.Errorf("Bad script '%s': %s", path, err))
 		}
 	}
+
+	// Check for properly formatted go os types
+	supported_syslist := []string{"darwin", "freebsd", "linux", "openbsd", "solaris", "windows"}
+	if len(config.OnlyOn) > 0 {
+		for _, provided_os := range config.OnlyOn {
+			supported_os := false
+			for _, go_os := range supported_syslist {
+				if provided_os == go_os {
+					supported_os = true
+					break
+				}
+			}
+			if supported_os != true {
+				return fmt.Errorf("Invalid OS specified in only_on: '%s'\n"+
+					"Supported OS names: %s", provided_os, strings.Join(supported_syslist, ", "))
+			}
+		}
+	}
+
 	if config.UseLinuxPathing {
 		for index, script := range config.Scripts {
 			scriptAbsPath, err := filepath.Abs(script)

common/shell-local/run.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"runtime"
 	"sort"
 	"strings"
 
@@ -27,6 +28,22 @@ type EnvVarsTemplate struct {
 }
 
 func Run(ui packer.Ui, config *Config) (bool, error) {
+	// Check if shell-local can even execute against this runtime OS
+	if len(config.OnlyOn) > 0 {
+		runCommand := false
+		for _, os := range config.OnlyOn {
+			if os == runtime.GOOS {
+				runCommand = true
+				break
+			}
+		}
+		if !runCommand {
+			ui.Say(fmt.Sprintf("Skipping shell-local due to runtime OS"))
+			log.Printf("[INFO] (shell-local): skipping shell-local due to missing runtime OS")
+			return true, nil
+		}
+	}
+
 	scripts := make([]string, len(config.Scripts))
 	if len(config.Scripts) > 0 {
 		copy(scripts, config.Scripts)

website/source/docs/post-processors/shell-local.html.md

@@ -91,6 +91,12 @@ Optional parameters:
     **Important:** If you customize this, be sure to include something like the
     `-e` flag, otherwise individual steps failing won't fail the provisioner.
 
+-  `only_on` (array of strings) - This is an array of 
+    [runtime operating systems](https://golang.org/doc/install/source#environment)
+    where `shell-local` will execute. This allows you to execute `shell-local` 
+    *only* on specific operating systems. By default, shell-local will always run 
+    if `only_on` is not set."
+
 -  `use_linux_pathing` (bool) - This is only relevant to windows hosts. If you
    are running Packer in a Windows environment with the Windows Subsystem for
    Linux feature enabled, and would like to invoke a bash script rather than

website/source/docs/provisioners/shell-local.html.md

@@ -108,6 +108,12 @@ Optional parameters:
     **Important:** If you customize this, be sure to include something like the
     `-e` flag, otherwise individual steps failing won't fail the provisioner.
 
+-  `only_on` (array of strings) - This is an array of 
+    [runtime operating systems](https://golang.org/doc/install/source#environment)
+    where `shell-local` will execute. This allows you to execute `shell-local` 
+    *only* on specific operating systems. By default, shell-local will always run 
+    if `only_on` is not set."
+
 -  `use_linux_pathing` (bool) - This is only relevant to windows hosts. If you
    are running Packer in a Windows environment with the Windows Subsystem for
    Linux feature enabled, and would like to invoke a bash script rather than