[server] Fix propragation of "workspace-permanent feature flags"

Author: geropl

components/gitpod-protocol/src/protocol.ts

@@ -298,6 +298,15 @@ export const WorkspaceFeatureFlags = {
     workspace_connection_limiting: undefined,
 };
 export type NamedWorkspaceFeatureFlag = keyof typeof WorkspaceFeatureFlags;
+export namespace NamedWorkspaceFeatureFlag {
+    export const WORKSPACE_PERSISTED_FEATTURE_FLAGS: NamedWorkspaceFeatureFlag[] = [
+        "full_workspace_backup",
+        "persistent_volume_claim",
+    ];
+    export function isWorkspacePersisted(ff: NamedWorkspaceFeatureFlag): boolean {
+        return WORKSPACE_PERSISTED_FEATTURE_FLAGS.includes(ff);
+    }
+}
 
 export interface EnvVarWithValue {
     name: string;

components/server/src/workspace/config-provider.ts

@@ -125,12 +125,8 @@ export class ConfigProvider {
              */
             delete config._featureFlags;
             if (!!user.featureFlags) {
-                const workspacePersistedFlags: NamedWorkspaceFeatureFlag[] = [
-                    "full_workspace_backup",
-                    "persistent_volume_claim",
-                ];
-                config._featureFlags = workspacePersistedFlags.filter((f) =>
-                    (user.featureFlags!.permanentWSFeatureFlags || []).includes(f),
+                config._featureFlags = (user.featureFlags!.permanentWSFeatureFlags || []).filter(
+                    NamedWorkspaceFeatureFlag.isWorkspacePersisted,
                 );
             }
 

components/server/src/workspace/workspace-starter.ts

@@ -829,7 +829,12 @@ export class WorkspaceStarter {
             let featureFlags: NamedWorkspaceFeatureFlag[] = workspace.config._featureFlags || [];
             featureFlags = featureFlags.concat(this.config.workspaceDefaults.defaultFeatureFlags);
             if (user.featureFlags && user.featureFlags.permanentWSFeatureFlags) {
-                featureFlags = featureFlags.concat(featureFlags, user.featureFlags.permanentWSFeatureFlags);
+                // Workspace-persisted feature flags are inherited from and controlled by workspace.config._featureFlags
+                // Make sure we do not overide them, here.
+                const nonWorkspacePersistentFeatureFlags = user.featureFlags.permanentWSFeatureFlags.filter(
+                    (ff) => !NamedWorkspaceFeatureFlag.isWorkspacePersisted(ff),
+                );
+                featureFlags = featureFlags.concat(featureFlags, nonWorkspacePersistentFeatureFlags);
             }
 
             // if the user has feature preview enabled, we need to add the respective feature flags.