From a7f1c11f3078d3100d0c5a77cceab0417c6b43dd Mon Sep 17 00:00:00 2001
From: Milan Pavlik <milan@gitpod.io>
Date: Wed, 15 Mar 2023 09:19:11 +0000
Subject: [PATCH] Revert "Remove workspace_classes_backend feature flag
 (#16825)"

This reverts commit afb724660182fcd480dc2e7fc06c45291b0023ad.
---
 .../src/cluster-service-server.ts             | 30 +++++++++++++++++--
 .../src/cluster-sync-service.ts               |  5 ++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/components/ws-manager-bridge/src/cluster-service-server.ts b/components/ws-manager-bridge/src/cluster-service-server.ts
index 7b06e546895af3..05fca4e873b9f6 100644
--- a/components/ws-manager-bridge/src/cluster-service-server.ts
+++ b/components/ws-manager-bridge/src/cluster-service-server.ts
@@ -44,6 +44,8 @@ import { getSupportedWorkspaceClasses } from "./cluster-sync-service";
 import { Configuration } from "./config";
 import { GRPCError } from "./rpc";
 import { isWorkspaceRegion } from "@gitpod/gitpod-protocol/lib/workspace-cluster";
+import { getExperimentsClientForBackend } from "@gitpod/gitpod-protocol/lib/experiments/configcat-server";
+import { GetWorkspacesRequest, WorkspaceManagerClient } from "@gitpod/ws-manager/lib";
 
 export interface ClusterServiceServerOptions {
     port: number;
@@ -148,8 +150,32 @@ export class ClusterService implements IClusterServiceServer {
                     tls,
                 };
 
-                let classConstraints = await getSupportedWorkspaceClasses(this.clientProvider, newCluster, false);
-                newCluster.admissionConstraints = admissionConstraints.concat(classConstraints);
+                const enabled = await getExperimentsClientForBackend().getValueAsync(
+                    "workspace_classes_backend",
+                    false,
+                    {},
+                );
+                if (enabled) {
+                    let classConstraints = await getSupportedWorkspaceClasses(this.clientProvider, newCluster, false);
+                    newCluster.admissionConstraints = admissionConstraints.concat(classConstraints);
+                } else {
+                    // try to connect to validate the config. Throws an exception if it fails.
+                    await new Promise<void>((resolve, reject) => {
+                        const c = this.clientProvider.createConnection(WorkspaceManagerClient, newCluster);
+                        c.getWorkspaces(new GetWorkspacesRequest(), (err: any) => {
+                            if (err) {
+                                reject(
+                                    new GRPCError(
+                                        grpc.status.FAILED_PRECONDITION,
+                                        `cannot reach ${req.url}: ${err.message}`,
+                                    ),
+                                );
+                            } else {
+                                resolve();
+                            }
+                        });
+                    });
+                }
 
                 await this.clusterDB.save(newCluster);
                 log.info({}, "cluster registered", { cluster: req.name });
diff --git a/components/ws-manager-bridge/src/cluster-sync-service.ts b/components/ws-manager-bridge/src/cluster-sync-service.ts
index 64ae32c7a13783..c0213075d29edd 100644
--- a/components/ws-manager-bridge/src/cluster-sync-service.ts
+++ b/components/ws-manager-bridge/src/cluster-sync-service.ts
@@ -42,6 +42,11 @@ export class ClusterSyncService {
     }
 
     private async reconcile() {
+        const enabled = await this.featureClient.getValueAsync("workspace_classes_backend", false, {});
+        if (!enabled) {
+            return;
+        }
+
         log.debug("reconciling workspace classes...");
         let allClusters = await this.clusterDB.findFiltered({});
         for (const cluster of allClusters) {