add a label to signal that a deploy is a chaos deploy (!265)

Resolves coop-cloud/organising#390 by adding the following label `coop-cloud.${STACK_NAME}.chaos=true` (according to the version label).
This is required for the auto updater coop-cloud/organising#236 (comment)

Co-authored-by: Moritz <moritz.m@local-it.org>
Reviewed-on: coop-cloud/abra#265

pkg/config/app.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"strconv"
 	"strings"
 
 	"github.com/schollz/progressbar/v3"
@@ -476,3 +477,15 @@ func SetRecipeLabel(compose *composetypes.Config, stackName string, recipe strin
 		}
 	}
 }
+
+// SetChaosLabel adds the label 'coop-cloud.${STACK_NAME}.chaos=true/false' to the app container
+// to signal if the app is deployed in chaos mode
+func SetChaosLabel(compose *composetypes.Config, stackName string, chaos bool) {
+	for _, service := range compose.Services {
+		if service.Name == "app" {
+			logrus.Debugf("set label 'coop-cloud.%s.chaos' to %s for %s", stackName, chaos, stackName)
+			labelKey := fmt.Sprintf("coop-cloud.%s.chaos", stackName)
+			service.Deploy.Labels[labelKey] = strconv.FormatBool(chaos)
+		}
+	}
+}