Cannot get the example-xds to work

I’m trying to get examples/example-xds to work.

I’m using Istio as XDS management server:

• ./bin/istioctl install --set profile=minimal (and Minikube for k8s)

This is my PoC app (copied the example’s code)

• https://github.com/alesj/quarkus_cl130/tree/xds

    public void startServer(@Observes StartupEvent evt) throws Exception {
        try (InputStream stream = getClass().getClassLoader().getResourceAsStream("bootstrap.json")) {
            byte[] xdsConfig = stream.readAllBytes();
            System.setProperty("io.grpc.xds.bootstrapConfig", new String(xdsConfig));
        }
        ServerCredentials credentials = InsecureServerCredentials.create();
        // Since the main server may be using TLS, we start a second server just for plaintext health
        // checks
        new Thread(() -> {
            try {
                server = XdsServerBuilder.forPort(port, credentials)
                    .addService(new HelloService())
                    .addService(ProtoReflectionService.newInstance()) // convenient for command line tools
                    .build()
                    .start();
                log.info("Listening on port " + port);
                server.awaitTermination();
            } catch (Exception e) {
                log.error("Error: ", e);
                Quarkus.asyncExit();
            }
        }, "xDS Server").start();
    }

I then build a Docker image out of this PoC app

• https://hub.docker.com/repository/docker/alesj/qcl-app

And deploy it into the same namespace as Istio

• kubectl apply -f k8s/qcl-app-deployment.yaml -n istio-system
• https://github.com/alesj/quarkus_cl130/tree/xds/k8s

My app then gets stuck on this log msg

• 2022-10-20 08:37:38,430 WARNING [io.grp.xds.XdsServerBuilder$DefaultListener] (grpc-timer-0) [port:30051] UNAVAILABLE: Listener grpc/server=xds.resource.listening_address=0.0.0.0:30051 unavailable
• https://gist.githubusercontent.com/alesj/dfc58b42c1727f8fe19bb5226de6132f/raw/cc6244eab86a6e2478e500d093b197ffde2b4cec/gistfile1.txt

The ‘gRPC server’ started (in the log) is another Quarkus gRPC server instance, which shouldn’t be an issue. (I’m using Quarkus’s gRPC support to simplify some of the stuff)

Afaics my xDS server can reach Istio, but not the other way around, right? Or what is that WARNING trying to tell me?

My node in bootstrap.json looks like this:

  "node": {
    "id": "router~0.0.0.0~myid~xyz",
    "cluster": "foobar"
  },

as I had to work around the error of not having 4 part, etc …

• https://github.com/istio/istio/blob/master/pilot/pkg/model/context.go#L955

Could this be an issue?

[alesj]

And this is how it looks when Quarkus does all the magic behind the scene 😃

• https://github.com/alesj/quarkus_cl130/blob/qxds/app/src/main/java/com/alesj/qcl/app/Configuration.java
• https://gist.githubusercontent.com/alesj/14e51855414d2375b6c17101cd9ddc0d/raw/fdd04ec59b117b6315a8bfe61447eadf360c5af3/gistfile1.txt

Instead of plain gRPC server Quarkus creates XDS based wrapper / server. And all the stubs get XDS channel.

# XDS
quarkus.grpc.server.xds.enabled=true
quarkus.grpc.server.port=30051

quarkus.grpc.clients.stub.name-resolver=xds
quarkus.grpc.clients.stub.host=qcl-app
quarkus.grpc.clients.stub.port=30051

[alesj]

Finally got it working on both ends – the client side then was easy, just had to code it and properly direct it to the target / server.

• https://gist.github.com/alesj/7308c9972471368fb502c308ef59a2a4

The code is here (as mentioned in the initial description)

• https://github.com/alesj/quarkus_cl130/tree/xds

It has some Quarkus magic: DI, Docker image build (via JIB), etc

Main code - single class 😃

• https://github.com/alesj/quarkus_cl130/blob/xds/app/src/main/java/com/alesj/qcl/app/Configuration.java

My k8s resources:

• https://github.com/alesj/quarkus_cl130/tree/xds/k8s