refactor: centralise app name validation

cli/internal/validate.go

@@ -3,6 +3,7 @@ package internal
 import (
 	"errors"
 
+	"coopcloud.tech/abra/pkg/config"
 	"coopcloud.tech/abra/pkg/recipe"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
@@ -22,3 +23,23 @@ func ValidateRecipeArg(c *cli.Context) string {
 
 	return recipeName
 }
+
+// ValidateAppNameArg ensures the app name arg is valid.
+func ValidateAppNameArg(c *cli.Context) string {
+	appName := c.Args().First()
+
+	if appName == "" {
+		ShowSubcommandHelpAndError(c, errors.New("no app provided"))
+	}
+
+	appFiles, err := config.LoadAppFiles("")
+	if err != nil {
+		logrus.Fatal(err)
+	}
+
+	if _, ok := appFiles[appName]; !ok {
+		logrus.Fatalf("'%s' doesn't exist?", appName)
+	}
+
+	return appName
+}