introduction

This paper verifies the communication process of gRCP service consumer mesha and gRPC service provider meshb deployed in Istio grid. Through this example, the external registry can be connected to the grid, which is no longer difficult.

1, Isito configuration points

Isito has been installed in the Kubernetes cluster, and verify that the following parameters are set correctly.

istio-config.yaml content

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  profile: default
  values:
    global:
      logging:
        level: default:debug
  meshConfig:
    accessLogFile: /dev/stdout
    defaultConfig:
      holdApplicationUntilProxyStarts: true
      proxyMetadata:
        ISTIO_META_DNS_CAPTURE: "true"
        ISTIO_META_DNS_AUTO_ALLOCATE: "true"
  components:
    pilot:
      hub: istio
      tag: 1.10.4

Description of key parameters

Execute the following command to validate the configuration

istioctl install -y -f istio-config.yaml

Verify the effective configuration with the following command

kubectl describe IstioOperator installed-state -n istio-system >> istioOperator.conf

2, Example description

Define Proto

The simple method SayHello is used to complete the communication between client and server.

syntax = "proto3";

option java_multiple_files = true;
option java_package = "com.melon.test.client.grpc";
option java_outer_classname = "HelloMesh";

package meshgrpc;

service Mesher {

  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

Service consumer mesha

@RestController
public class MeshSender {

    @GetMapping("demo")
    public String meshWorker(){

         String target = "dns:///AppMeshClient.mesh:50000";
        // String  target = "127.0.0.1:50000";
        ManagedChannel channel = ManagedChannelBuilder.forTarget(target)
                .usePlaintext()
                .build();
        MesherGrpc.MesherBlockingStub blockingStub = MesherGrpc.newBlockingStub(channel);
        HelloRequest request = HelloRequest.newBuilder().setName("mesh demo!").build();
        HelloReply reply = blockingStub.sayHello(request);
        System.out.println(reply.getMessage());
        return reply.getMessage();

    }
}

Service provider meshb

@Component
public class MeshReceiver {


  @PostConstruct
  public void receiverWorker() throws IOException {
    int port = 50000;
    Server server = ServerBuilder.forPort(port)
      .addService(new MeshBService())
      .build()
      .start();
    System.out.println("Server started.");
  }

  class  MeshBService extends MesherGrpc.MesherImplBase {

    public void sayHello(HelloRequest request,
                         io.grpc.stub.StreamObserver<HelloReply> responseObserver) {

      System.out.println("receiver client message: " + request.getName());
      HelloReply reply = HelloReply.newBuilder().setMessage("I'm from server " + request.getName()).build();
      responseObserver.onNext(reply);
      responseObserver.onCompleted();
    }
  }

}

Image push

<plugin>
  <groupId>com.google.cloud.tools</groupId>
  <artifactId>jib-maven-plugin</artifactId>
  <version>3.1.4</version>
  <configuration>
    <from>
      <image>
        harbor.x.x/x/java:8u212-full
      </image>
      <auth>
        <username>${harbor.username}</username>
        <password>${harbor.password}</password>
      </auth>
    </from>
    <to>
      <image>x.x.x/x/${project.name}</image>
      <auth>
        <username>${harbor.username}</username>
        <password>${harbor.password}</password>
      </auth>
      <tags>
        <tag>${project.version}</tag>
        <tag>latest</tag>
      </tags>
    </to>
    <container>
      <ports>
        <port>x</port>
      </ports>
      <creationTime>USE_CURRENT_TIMESTAMP</creationTime>
    </container>
  </configuration>
</plugin>

Note: through the maven plug-in jib, execute the following command: "mvn compile jib:build" to push the image to the harbor warehouse

3, gRPC service provider deployment

Set the Deployment of the meshb service

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: meshb
  labels:
    app: meshb
spec:
  selector:
    matchLabels:
      app: meshb
  replicas: 1
  template:
    metadata:
      labels:
        app: meshb
    spec:
      imagePullSecrets:
        - name: xxxx #Warehouse name
      containers:
        - name: meshb
          image: x.x.x.x/x/meshb:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 50000

Execute the following command to take effect

kubectl apply -f meshb.yaml
deployment.apps/meshb created

Check whether the operation status is normal

# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
meshb-565945d794-wcb8z              2/2     Running   0          9m19s

View the startup log. Startup succeeded

# kubectl logs meshb-565945d794-wcb8z -n default

 Server started.
2021-11-05 09:21:19.828  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8181 (http) with context path ''
2021-11-05 09:21:19.847  INFO 1 --- [           main] com.melon.test.MeshbApplication          : Started MeshbApplication in 3.859 seconds (JVM running for 4.344)

Note: the gRPC service provider has been deployed so far.

4, gRPC service consumer deployment

Set the Deployment of the mesha service

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mesha
  labels:
    app: mesha
spec:
  selector:
    matchLabels:
      app: mesha
  replicas: 1
  template:
    metadata:
      labels:
        app: mesha
    spec:
      imagePullSecrets:
        - name: middleware
      containers:
        - name: mesha
          image: arbor.helxike.cn/base/mesha:latest
          ports:
            - containerPort: 7171
          imagePullPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
  name: mesha
spec:
  selector:
    app: mesha
  type: LoadBalancer
  ports:
    - name: web

Execute command deployment

# kubectl apply -f mesha.yaml
deployment.apps/mesha created
service/mesha created

View service status

# kubectl get service
NAME                      TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
mesha                     LoadBalancer   10.x.61.x    <pending>     7171:30514/TCP   20s

View Pod running status

# kubectl get pods
NAME                                READY   STATUS     RESTARTS   AGE
mesha-b559fc4f4-m9752               2/2     Running    0          87s

Note: so far, the service consumer has been deployed.

4, Service call validation

Access via domain name

http://x.x.x.x:30514/demo

Page printing error

Viewing the log found that the domain name could not be resolved:

kubectl logs -f mesha-b559fc4f4-m9752  -n default

2021-11-05 09:01:37.372  WARN 1 --- [ault-executor-0] io.grpc.internal.ManagedChannelImpl      : [Channel<1>: (dns:///AppMeshClient.mesh:50000)] Failed to resolve name. status=Status{code=UNAVAILABLE, description=Unable to resolve host AppMeshClient.mesh, cause=java.lang.RuntimeException: java.net.UnknownHostException: AppMeshClient.mesh: Name or service not known
 at io.grpc.internal.DnsNameResolver.resolveAll(DnsNameResolver.java:436)
 at io.grpc.internal.DnsNameResolver$Resolve.resolveInternal(DnsNameResolver.java:272)
 at io.grpc.internal.DnsNameResolver$Resolve.run(DnsNameResolver.java:228)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.UnknownHostException: AppMeshClient.mesh: Name or service not known
 at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
 at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:929)
 at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1324)
 at java.net.InetAddress.getAllByName0(InetAddress.java:1277)
 at java.net.InetAddress.getAllByName(InetAddress.java:1193)
 at java.net.InetAddress.getAllByName(InetAddress.java:1127)
 at io.grpc.internal.DnsNameResolver$JdkAddressResolver.resolveAddress(DnsNameResolver.java:646)
 at io.grpc.internal.DnsNameResolver.resolveAll(DnsNameResolver.java:404)
 ... 5 more
}

Mapping service provider IP through ServiceEntry

Check that the IP address of the service provider meshb is x.x.0.17

# kubectl get pods -o wide
NAME                                READY   STATUS    RESTARTS   AGE     IP             NODE                NOMINATED NODE   READINESS GATES
mesha-b559fc4f4-m9752               2/2     Running   0          140m    x.x.1.117   k8s-servicemesh-3   <none>           <none>
meshb-565945d794-wcb8z              2/2     Running   0          118m    x.x.0.17    k8s-servicemesh-1   <none>           <none>

meshb-service-entry.yaml content

apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: meshb
spec:
  endpoints:
    - address: x.x.0.17
  hosts:
    - AppMeshClient.mesh
  location: MESH_INTERNAL
  ports:
    - name: grpc
      number: 50000
      protocol: grpc
  resolution: STATIC

Execute the following command to validate ServiceEntry

kubectl apply -f meshb-service-entry.yaml
serviceentry.networking.istio.io/meshb created

Visit the page again and find that it is normal

Note: at this point, the service consumer initiates a call to the service provider in the grid.

5, Log verification trace

View the service consumer mesha log

kubectl logs -f mesha-b559fc4f4-m9752  -n default

I'm from server mesh demo!

Note: the information returned by the service consumer mesha from the service provider meshb.

View the service provider meshb log

# kubectl logs -f meshb-565945d794-wcb8z -n default

2021-11-05 09:21:19.828  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8181 (http) with context path ''
2021-11-05 09:21:19.847  INFO 1 --- [           main] com.melon.test.MeshbApplication          : Started MeshbApplication in 3.859 seconds (JVM running for 4.344)
receiver client message: mesh demo!

Note: the service provider meshb has received the request from the service consumer mesha.

View the envoy log of the service consumer mesha

kubectl logs -f -l app=mesha -c istio-proxy -n default
2021-11-05T10:25:17.772317Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
2021-11-05T10:52:35.856445Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T10:52:36.093048Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
[2021-11-05T11:06:23.510Z] "GET /demo HTTP/1.1" 500 - via_upstream - "-" 0 x 37 36 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36" "49cd74d8-86eb-4ef5-bd71-8236d188c2f9" "10.69.x1.156:30514" "10.166.1.11x:7171" inbound|7171|| 127.0.0.6:41007 10.166.1.117:7171 10.166.0.0:20826 - default
2021-11-05T11:22:58.633956Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T11:22:59.100387Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
[2021-11-05T11:27:23.842Z] "POST /meshgrpc.Mesher/SayHello HTTP/2" 200 - via_upstream - "-" 17 33 371 319 "-" "grpc-java-netty/1.28.0" "79f2edbd-9c31-4265-87fb-38a594d9383b" "AppMeshClient.mesh:50000" "10.166.0.17:50000" outbound|50000||AppMeshClient.mesh 10.166.x.117:51914 240.240.0.63:50000 10.166.x.117:40544 - default
[2021-11-05T11:27:23.527Z] "GET /demo HTTP/1.1" 200 - via_upstream - "-" 0 26 x 728 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36" "859344b6-012d-4457-a391-2b4d13aa3e35" "10.69.x1.156:30514" "10.166.1.11x:7171" inbound|7171|| 127.0.0.6:47065 10.166.1.117:7171 10.166.0.0:2410 - default

View the envoy log of the service consumer meshb

# kubectl logs -f -l app=meshb -c istio-proxy -n default
2021-11-05T09:57:12.490428Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T09:57:12.765887Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
2021-11-05T10:24:48.767511Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T10:24:48.914475Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
2021-11-05T10:57:52.604281Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T10:57:52.757736Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
2021-11-05T11:26:56.551824Z warning envoy config StreamAggregatedResources gRPC config stream closed: 14, transport is closing
2021-11-05T11:26:56.987345Z info xdsproxy connected to upstream XDS server: istiod.istio-system.svc:15012
[2021-11-05T11:27:23.844Z] "POST /meshgrpc.Mesher/SayHello HTTP/2" 200 - via_upstream - "-" 17 33x 316 "-" "grpc-java-netty/1.28.0" "79f2edbd-9c31-4265-87fb-38a594d9383b" "AppMeshClient.mesh:50000" "10.166.0.17:50000" inbound|50000|| 127.0.0.6:44221 10.166.0.17:50000 10.166.1.117:51914 - default

Log in to the Pod of mesa for verification

kubectl describe pod/mesha-b559fc4f4-m9752 -n default

[12:04:44root@mesha-b559fc4f4-m9752 /] C:2
# curl -v AppMeshClient.mesh
* About to connect() to AppMeshClient.mesh port 80 (#0)
*   Trying 240.240.0.63...
* Connected to AppMeshClient.mesh (240.240.0.63) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: AppMeshClient.mesh
> Accept: */*
>
< HTTP/1.1 503 Service Unavailable
< content-length: 91
< content-type: text/plain
< date: Fri, 05 Nov 2021 12:04:59 GMT
< server: envoy
<
* Connection #0 to host AppMeshClient.mesh left intact
upstream connect error or disconnect/reset before headers. reset reason: connection failure

Note: log in to the Pod of mesha and access the domain name AppMeshClient.mesh. It is found that it automatically assigns IP "240.240.0.63" and points to sidecar "envy", which will redirect the traffic of the service container to sidecar through DNS Proxy.

Note: by viewing the service consumer logs, service provider logs and their data plane enovy logs, it shows that their calls are made in the istio grid.