refactor: first pass at rewriting apps plugin in go

plugins/apps/triggers.go

@@ -0,0 +1,55 @@
+package apps
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// TriggerAppCreateis a trigger to create an app
+func TriggerAppCreate(appName string) error {
+	return createApp(appName)
+}
+
+// TriggerAppDestroy is a trigger to destroy an app
+func TriggerAppDestroy(appName string) error {
+	return destroyApp(appName)
+}
+
+// TriggerAppExists is a trigger to check if an app exists
+func TriggerAppExists(appName string) error {
+	return appExists(appName)
+}
+
+// TriggerAppMaybeCreate is a trigger to allow gated app creation
+func TriggerAppMaybeCreate(appName string) error {
+	return maybeCreateApp(appName)
+}
+
+// TriggerPostDelete is the apps post-delete plugin trigger
+func TriggerPostDelete(appName string) error {
+	imageRepo := common.GetAppImageRepo(appName)
+
+	if appName != "" {
+		// remove contents for apps that are symlinks to other folders
+		os.RemoveAll(fmt.Sprintf("%v/", common.AppRoot(appName)))
+		// then remove the folder and/or the symlink
+		os.RemoveAll(common.AppRoot(appName))
+	}
+
+	imagesByAppLabel, err := listImagesByAppLabel(appName)
+	if err != nil {
+		common.LogWarn(err.Error())
+	}
+
+	imagesByRepo, err := listImagesByImageRepo(imageRepo)
+	if err != nil {
+		common.LogWarn(err.Error())
+	}
+
+	images := append(imagesByAppLabel, imagesByRepo...)
+	common.RemoveImages(images)
+
+	return nil
+}