feat: create proxy:build-config command

Closes #4024

plugins/proxy/Makefile

@@ -1,4 +1,4 @@
-SUBCOMMANDS = subcommands/disable subcommands/enable subcommands/ports subcommands/ports-add subcommands/ports-clear subcommands/ports-remove subcommands/ports-set subcommands/report subcommands/set
+SUBCOMMANDS = subcommands/build-config subcommands/disable subcommands/enable subcommands/ports subcommands/ports-add subcommands/ports-clear subcommands/ports-remove subcommands/ports-set subcommands/report subcommands/set
 TRIGGERS = triggers/proxy-is-enabled triggers/proxy-type triggers/post-certs-remove triggers/post-certs-update triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = proxy

plugins/proxy/src/commands/commands.go

@@ -18,6 +18,7 @@ Manage the proxy integration for an app
 Additional commands:`
 
 	helpContent = `
+	proxy:build-config <app>, (Re)builds config for a given app
     proxy:disable <app>, Disable proxy for app
     proxy:enable <app>, Enable proxy for app
     proxy:ports <app>, List proxy port mappings for app

plugins/proxy/src/subcommands/subcommands.go

@@ -17,6 +17,11 @@ func main() {
 
 	var err error
 	switch subcommand {
+	case "build-config":
+		args := flag.NewFlagSet("proxy:build-config", flag.ExitOnError)
+		args.Parse(os.Args[2:])
+		appName := args.Arg(0)
+		err = proxy.CommandBuildConfig(appName)
 	case "disable":
 		args := flag.NewFlagSet("proxy:disable", flag.ExitOnError)
 		skipRestart := args.Bool("no-restart", false, "--no-restart: skip restart of the app")

plugins/proxy/subcommands.go

@@ -8,6 +8,19 @@ import (
 	"github.com/dokku/dokku/plugins/config"
 )
 
+// CommandBuildConfig rebuilds config for a given app
+func CommandBuildConfig(appName string) error {
+	if appName == "" {
+		return errors.New("Please specify an app to run the command on")
+	}
+
+	if err := common.VerifyAppName(appName); err != nil {
+		return err
+	}
+
+	return common.PlugnTrigger("proxy-build-config", []string{appName}...)
+}
+
 // CommandDisable disables the proxy for app via command line
 func CommandDisable(appName string, skipRestart bool) error {
 	if appName == "" {