[ws-manager-bridge] Improve initial connection error handling

Prior we might return `UNAVAILABLE` which would make some
gRPC clients retry.

Author: csweichel

components/ws-manager-api/typescript/src/client-provider.ts

@@ -12,7 +12,6 @@ import { Disposable } from "@gitpod/gitpod-protocol";
 import { WorkspaceClusterWoTls, WorkspaceManagerConnectionInfo } from '@gitpod/gitpod-protocol/lib/workspace-cluster';
 import { WorkspaceManagerClientProviderCompositeSource, WorkspaceManagerClientProviderSource } from "./client-provider-source";
 import { log } from '@gitpod/gitpod-protocol/lib/util/logging';
-import { GetWorkspacesRequest } from "./core_pb";
 
 @injectable()
 export class WorkspaceManagerClientProvider implements Disposable {
@@ -56,14 +55,14 @@ export class WorkspaceManagerClientProvider implements Disposable {
         let client = this.connectionCache.get(name);
         if (!client) {
             const info = await getConnectionInfo();
-            client = createClient(info, grpcOptions);
+            client = this.createClient(info, grpcOptions);
             this.connectionCache.set(name, client);
         } else if(client.getChannel().getConnectivityState(true) != grpc.connectivityState.READY) {
             client.close();
 
             console.warn(`Lost connection to workspace manager \"${name}\" - attempting to reestablish`);
             const info = await getConnectionInfo();
-            client = createClient(info, grpcOptions);
+            client = this.createClient(info, grpcOptions);
             this.connectionCache.set(name, client);
         }
 
@@ -78,39 +77,30 @@ export class WorkspaceManagerClientProvider implements Disposable {
         return this.source.getAllWorkspaceClusters();
     }
 
-    /**
-     * Tries to establish a gRPC connection to the specified target. Throws an exception if it fails.
-     * @param info 
-     */
-    public async tryConnectTo(info: WorkspaceManagerConnectionInfo) {
-        const client = new PromisifiedWorkspaceManagerClient(createClient(info));
-        await client.getWorkspaces({}, new GetWorkspacesRequest());
+    public createClient(info: WorkspaceManagerConnectionInfo, grpcOptions?: object): WorkspaceManagerClient {
+        let credentials: grpc.ChannelCredentials;
+        if (info.tls) {
+            const rootCerts = Buffer.from(info.tls.ca, "base64");
+            const privateKey = Buffer.from(info.tls.key, "base64");
+            const certChain = Buffer.from(info.tls.crt, "base64");
+            credentials = grpc.credentials.createSsl(rootCerts, privateKey, certChain);
+            log.debug("using TLS config to connect ws-manager");
+        } else {
+            credentials = grpc.credentials.createInsecure();
+        }
+
+        const options = {
+            ...grpcOptions,
+            'grpc.ssl_target_name_override': "ws-manager",  // this makes sure we can call ws-manager with a URL different to "ws-manager"
+        };
+        return new WorkspaceManagerClient(info.url, credentials, options);
     }
 
     public dispose() {
         Array.from(this.connectionCache.values()).map(c => c.close());
     }
 }
 
-function createClient(info: WorkspaceManagerConnectionInfo, grpcOptions?: object): WorkspaceManagerClient {
-    let credentials: grpc.ChannelCredentials;
-    if (info.tls) {
-        const rootCerts = Buffer.from(info.tls.ca, "base64");
-        const privateKey = Buffer.from(info.tls.key, "base64");
-        const certChain = Buffer.from(info.tls.crt, "base64");
-        credentials = grpc.credentials.createSsl(rootCerts, privateKey, certChain);
-        log.debug("using TLS config to connect ws-manager");
-    } else {
-        credentials = grpc.credentials.createInsecure();
-    }
-
-    const options = {
-        ...grpcOptions,
-        'grpc.ssl_target_name_override': "ws-manager",  // this makes sure we can call ws-manager with a URL different to "ws-manager"
-    };
-    return new WorkspaceManagerClient(info.url, credentials, options);
-}
-
 /**
  * 
  * @param clusters 

components/ws-manager-bridge/src/cluster-service-server.ts

@@ -22,6 +22,7 @@ import {
     UpdateRequest,
     UpdateResponse
 } from '@gitpod/ws-manager-bridge-api/lib';
+import { GetWorkspacesRequest } from '@gitpod/ws-manager/lib';
 import { WorkspaceManagerClientProvider } from '@gitpod/ws-manager/lib/client-provider';
 import * as grpc from "grpc";
 import { inject, injectable } from 'inversify';
@@ -107,7 +108,16 @@ export class ClusterService implements IClusterServiceServer {
                 };
 
                 // try to connect to validate the config. Throws an exception if it fails.
-                await this.clientProvider.tryConnectTo(newCluster);
+                await new Promise<void>((resolve, reject) => {
+                    const c = this.clientProvider.createClient(newCluster);
+                    c.getWorkspaces(new GetWorkspacesRequest(), (err, resp) => {
+                        if (err) {
+                            reject(new GRPCError(grpc.status.FAILED_PRECONDITION, `cannot reach ${req.url}: ${err.message}`));
+                        } else {
+                            resolve();
+                        }
+                    });
+                })
 
                 await this.db.save(newCluster);