refactor: move app listing back to common

Without this, we'd need to duplicate some logic or make it more complex via a plugin trigger.

plugins/apps/apps.go

@@ -1,13 +1,5 @@
 package apps
 
-import (
-	"fmt"
-	"io/ioutil"
-	"strings"
-
-	"github.com/dokku/dokku/plugins/common"
-)
-
 var (
 	// DefaultProperties is a map of all valid network properties with corresponding default property values
 	DefaultProperties = map[string]string{
@@ -21,30 +13,3 @@ var (
 		"deploy-source-metadata": true,
 	}
 )
-
-// DokkuApps returns a list of all local apps
-func DokkuApps() ([]string, error) {
-	apps := []string{}
-	dokkuRoot := common.MustGetEnv("DOKKU_ROOT")
-	files, err := ioutil.ReadDir(dokkuRoot)
-	if err != nil {
-		return apps, fmt.Errorf("You haven't deployed any applications yet")
-	}
-
-	for _, f := range files {
-		appRoot := common.AppRoot(f.Name())
-		if !common.DirectoryExists(appRoot) {
-			continue
-		}
-		if strings.HasPrefix(f.Name(), ".") {
-			continue
-		}
-		apps = append(apps, f.Name())
-	}
-
-	if len(apps) == 0 {
-		return apps, fmt.Errorf("You haven't deployed any applications yet")
-	}
-
-	return filterApps(apps)
-}