Add prefix factory option

This allows us to re-use existing clusters and can greatly fasten
the testing time.

e2e/fixtures/factory.go

@@ -250,9 +250,12 @@ func (factory *Factory) getContainerOverrides(
 	return mainOverrides, sidecarOverrides
 }
 
-// getClusterPrefix returns the cluster name prefix.
 func (factory *Factory) getClusterPrefix() string {
-	return fmt.Sprintf("fdb-cluster-%s", RandStringRunes(8))
+	prefix := factory.options.prefix
+	if prefix == "" {
+		return fmt.Sprintf("fdb-cluster-%s", RandStringRunes(8))
+	}
+	return prefix
 }
 
 // GetDefaultStorageClass returns either the StorageClass provided by the command line or fetches the StorageClass passed on

e2e/fixtures/options.go

@@ -33,6 +33,7 @@ import (
 type FactoryOptions struct {
 	namespace                   string
 	chaosNamespace              string
+	prefix                      string
 	context                     string
 	fdbImage                    string // TODO (johscheuer): Make this optional if we use the default
 	sidecarImage                string // TODO (johscheuer): Make this optional if we use the default
@@ -65,6 +66,12 @@ func (options *FactoryOptions) BindFlags(fs *flag.FlagSet) {
 		"",
 		"defines the chaos namespace to run experiments (will be created if missing)",
 	)
+	fs.StringVar(
+		&options.prefix,
+		"prefix",
+		"",
+		"defines the prefix of fdb cluster to run the test (will be created if missing)",
+	)
 	fs.StringVar(
 		&options.context,
 		"context",