Initial commit for Ads Service.

kubernetes-manifests/adsservice.yaml

@@ -0,0 +1,67 @@
+# Copyright 2018 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: adsservice
+spec:
+  template:
+    metadata:
+      labels:
+        app: adsservice
+    spec:
+      terminationGracePeriodSeconds: 5
+      containers:
+      - name: server
+        image: gcr.io/istio-next/adsservice
+        ports:
+        - containerPort: 9555
+        env:
+        - name: PORT
+          value: "9555"
+        - name: LISTEN_ADDR
+          value: "0.0.0.0"
+        - name: ADS_URL
+          value: "http://localhost:10010/ads/"
+        resources:
+          requests:
+            cpu: 200m
+            memory: 64Mi
+          limits:
+            cpu: 300m
+            memory: 128Mi
+        readinessProbe:
+          tcpSocket:
+            port: 9555
+          initialDelaySeconds: 15
+          periodSeconds: 10
+        livenessProbe:
+          tcpSocket:
+            port: 9555
+          initialDelaySeconds: 15
+          periodSeconds: 10
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: adsservice
+spec:
+  type: ClusterIP
+  selector:
+    app: adsservice
+  ports:
+  - name: grpc
+    port: 9555
+    targetPort: 9555

skaffold.yaml

@@ -34,6 +34,8 @@ build:
     workspace: src/currencyservice
   - imageName: gcr.io/microservices-demo-app/cartservice
     workspace: src/cartservice
+  - imageName: gcr.io/istio-next/adsservice
+    workspace: src/adsservice
   - imageName: gcr.io/microservices-demo-app/frontend
     workspace: src/frontend
   - imageName: gcr.io/microservices-demo-app/loadgenerator

src/adsservice/.gitignore

@@ -0,0 +1,10 @@
+*.iml
+*.ipr
+*.iws
+.gradle/**
+.idea/**
+build/**
+gradle/**
+gradlew.bat
+
+

src/adsservice/Dockerfile

@@ -0,0 +1,9 @@
+# cartservice
+FROM openjdk:8
+RUN apt-get update && apt-get install net-tools telnet
+WORKDIR /app
+COPY build/install .
+EXPOSE 9555
+ENTRYPOINT ["/app/hipstershop/bin/AdsService"]
+#ENTRYPOINT ["ls /"]
+

src/adsservice/build.gradle

@@ -0,0 +1,103 @@
+description = 'OpenCensus Examples'
+
+buildscript {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+        maven {
+            url "https://plugins.gradle.org/m2/"
+        }
+    }
+    dependencies {
+        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.3'
+    }
+}
+
+apply plugin: 'idea'
+apply plugin: 'java'
+apply plugin: 'com.google.protobuf'
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+}
+
+group = "adservice"
+version = "0.1.0-SNAPSHOT" // CURRENT_OPENCENSUS_VERSION
+
+def opencensusVersion = "0.14.0" // LATEST_OPENCENSUS_RELEASE_VERSION
+def grpcVersion = "1.10.1" // CURRENT_GRPC_VERSION
+def prometheusVersion = "0.3.0"
+
+tasks.withType(JavaCompile) {
+    sourceCompatibility = '1.8'
+    targetCompatibility = '1.8'
+}
+
+dependencies {
+    compile "com.google.api.grpc:proto-google-common-protos:1.11.0",
+            "io.opencensus:opencensus-exporter-stats-prometheus:${opencensusVersion}",
+            "io.opencensus:opencensus-exporter-stats-stackdriver:${opencensusVersion}",
+            "io.opencensus:opencensus-exporter-trace-stackdriver:${opencensusVersion}",
+            "io.opencensus:opencensus-exporter-trace-logging:${opencensusVersion}",
+            "io.grpc:grpc-protobuf:${grpcVersion}",
+            "io.grpc:grpc-stub:${grpcVersion}",
+            "io.grpc:grpc-netty:${grpcVersion}",
+            "io.prometheus:simpleclient_httpserver:${prometheusVersion}"
+
+    runtime "io.opencensus:opencensus-impl:${opencensusVersion}",
+            "io.netty:netty-tcnative-boringssl-static:2.0.8.Final"
+}
+
+protobuf {
+    protoc {
+        artifact = 'com.google.protobuf:protoc:3.5.1-1'
+    }
+    plugins {
+        grpc {
+            artifact = "io.grpc:protoc-gen-grpc-java:${grpcVersion}"
+        }
+    }
+    generateProtoTasks {
+        all()*.plugins {
+            grpc {}
+        }
+        ofSourceSet('main')
+    }
+}
+
+// Inform IDEs like IntelliJ IDEA, Eclipse or NetBeans about the generated code.
+sourceSets {
+    main {
+        java {
+            srcDirs 'hipstershop'
+            srcDirs 'build/generated/source/proto/main/java'
+            srcDirs 'build/generated/source/proto/main/grpc/hipstershop'
+        }
+    }
+}
+
+// Provide convenience executables for trying out the examples.
+apply plugin: 'application'
+
+startScripts.enabled = false
+
+task adsService(type: CreateStartScripts) {
+    mainClassName = 'hipstershop.AdsService'
+    applicationName = 'AdsService'
+    outputDir = new File(project.buildDir, 'tmp')
+    classpath = jar.outputs.files + project.configurations.runtime
+}
+
+task adsServiceClient(type: CreateStartScripts) {
+    mainClassName = 'hipstershop.AdsServiceClient'
+    applicationName = 'AdsServiceClient'
+    outputDir = new File(project.buildDir, 'tmp')
+    classpath = jar.outputs.files + project.configurations.runtime
+}
+
+applicationDistribution.into('bin') {
+    from(adsService)
+    from(adsServiceClient)
+    fileMode = 0755
+}

src/adsservice/gradlew

@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

src/adsservice/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'hipstershop'

src/adsservice/src/main/java/hipstershop/AdsService.java

@@ -0,0 +1,187 @@
+package hipstershop;
+
+import com.google.common.collect.ImmutableMap;
+import hipstershop.Demo.Ads;
+import hipstershop.Demo.AdsRequest;
+import hipstershop.Demo.AdsResponse;
+import io.grpc.Server;
+import io.grpc.ServerBuilder;
+import io.grpc.stub.StreamObserver;
+import io.opencensus.common.Duration;
+import io.opencensus.contrib.grpc.metrics.RpcViews;
+import io.opencensus.exporter.stats.prometheus.PrometheusStatsCollector;
+import io.opencensus.exporter.trace.logging.LoggingTraceExporter;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsConfiguration;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsExporter;
+import io.opencensus.exporter.trace.stackdriver.StackdriverTraceConfiguration;
+import io.opencensus.exporter.trace.stackdriver.StackdriverTraceExporter;
+import io.opencensus.trace.AttributeValue;
+import io.opencensus.trace.Span;
+import io.opencensus.trace.Tracer;
+import io.opencensus.trace.Tracing;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+
+public class AdsService {
+  private static final Logger logger = Logger.getLogger(AdsService.class.getName());
+
+  private static final Tracer tracer = Tracing.getTracer();
+
+  private int MAX_ADS_TO_SERVE = 2;
+  private Server server;
+
+  static final AdsService service = new AdsService();
+  private void start() throws IOException {
+    int port = Integer.parseInt(System.getenv("PORT"));
+    server = ServerBuilder.forPort(port).addService(new AdsServiceImpl()).build().start();
+    logger.info("Server started, listening on " + port);
+    Runtime.getRuntime()
+        .addShutdownHook(
+            new Thread() {
+              @Override
+              public void run() {
+                // Use stderr here since the logger may have been reset by its JVM shutdown hook.
+                System.err.println("*** shutting down gRPC ads server since JVM is shutting down");
+                AdsService.this.stop();
+                System.err.println("*** server shut down");
+              }
+            });
+  }
+
+  private void stop() {
+    if (server != null) {
+      server.shutdown();
+    }
+  }
+
+  static class AdsServiceImpl extends hipstershop.AdsServiceGrpc.AdsServiceImplBase {
+
+    /**
+     * Retrieves ads based on context provided in the request {@code AdsRequest}.
+     *
+     * @param req the request containing context.
+     * @param responseObserver the stream observer which gets notified with the value of
+     *     {@code AdsResponse}
+     */
+    @Override
+    public void getAds(AdsRequest req, StreamObserver<AdsResponse> responseObserver) {
+      logger.info("Servicing getAds");
+      AdsService service = AdsService.getInstance();
+      Span span = tracer.getCurrentSpan();
+      span.putAttribute("method", AttributeValue.stringAttributeValue("getAds"));
+      span.addAnnotation(
+          "Constructing Ads Request.",
+          ImmutableMap.of(
+              "Context Keys", AttributeValue.stringAttributeValue(req.getContextKeysList().toString()),
+              "Context Keys length", AttributeValue.longAttributeValue(req.getContextKeysCount())));
+      List<Ads> ads = new ArrayList<>();
+      if (req.getContextKeysCount() > 0) {
+        span.addAnnotation("Getting Ads by context.");
+        for (int i = 0; i<req.getContextKeysCount(); i++) {
+          Ads ad = service.getAdsByKey(req.getContextKeys(i));
+          if (ad != null) {
+            ads.add(ad);
+          }
+        }
+      } else {
+        span.addAnnotation("Getting default Ads.");
+        ads = service.getDefaultAds();
+      }
+      if (ads.isEmpty()) {
+        // Serve default ads.
+        span.addAnnotation("NoGetting default Ads.");
+        ads = service.getDefaultAds();
+      }
+      AdsResponse reply = AdsResponse.newBuilder().addAllAds(ads).build();
+      responseObserver.onNext(reply);
+      responseObserver.onCompleted();
+      logger.info("Responded to getAds");
+    }
+  }
+
+  static final HashMap<String, Ads> cacheMap = new HashMap<String, Ads>();
+
+  Ads getAdsByKey(String key) {
+    return cacheMap.get(key);
+  }
+
+
+  public List<Ads> getDefaultAds() {
+    List<Ads> ads = new ArrayList<>();
+    Iterator iterator = cacheMap.entrySet().iterator();
+    while (iterator.hasNext()) {
+      Map.Entry pair = (Map.Entry)iterator.next();
+      ads.add((Ads)pair.getValue());
+      if (ads.size() >= MAX_ADS_TO_SERVE) {
+        break;
+      }
+    }
+    return ads;
+  }
+
+  public static AdsService getInstance() {
+    return service;
+  }
+
+  /** Await termination on the main thread since the grpc library uses daemon threads. */
+  private void blockUntilShutdown() throws InterruptedException {
+    if (server != null) {
+      server.awaitTermination();
+    }
+  }
+
+  static void initializeAds() {
+    // TODO: Replace localhost with
+    String adsUrl = System.getenv("ADS_URL");
+    cacheMap.put("camera", Ads.newBuilder().setRedirectUrl(adsUrl + "/camera")
+        .setText("MyPro camera for sale. 50% off.").build());
+    cacheMap.put("bike", Ads.newBuilder().setRedirectUrl(adsUrl + "/bike")
+        .setText("ZoomZoom bike for sale. 10% off.").build());
+    cacheMap.put("kitchen", Ads.newBuilder().setRedirectUrl(adsUrl + "/kitchen")
+        .setText("CutPro knife for sale. Buy one, get second set for free").build());
+    logger.info("Default Ads initialized");
+  }
+
+  /** Main launches the server from the command line. */
+  public static void main(String[] args) throws IOException, InterruptedException {
+    // Add final keyword to pass checkStyle.
+    final String cloudProjectId = System.getenv("GCP_PROJECT_ID");
+    logger.info("GCP Project ID is " + cloudProjectId);
+
+    initializeAds();
+
+    // Registers all RPC views.
+    RpcViews.registerAllViews();
+
+    // Registers logging trace exporter.
+    LoggingTraceExporter.register();
+
+
+    // Registers Stackdriver exporters.
+    if (cloudProjectId != null) {
+      StackdriverTraceExporter.createAndRegister(
+          StackdriverTraceConfiguration.builder().setProjectId(cloudProjectId).build());
+      StackdriverStatsExporter.createAndRegister(
+          StackdriverStatsConfiguration.builder()
+              .setProjectId(cloudProjectId)
+              .setExportInterval(Duration.create(15, 0))
+              .build());
+    }
+
+    // Register Prometheus exporters and export metrics to a Prometheus HTTPServer.
+    PrometheusStatsCollector.createAndRegister();
+
+    // Start the RPC server. You shouldn't see any output from gRPC before this.
+    logger.info("AdsService starting.");
+    final AdsService service = AdsService.getInstance();
+    service.start();
+    service.blockUntilShutdown();
+  }
+}

src/adsservice/src/main/java/hipstershop/AdsServiceClient.java

@@ -0,0 +1,173 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package hipstershop;
+
+
+import com.google.common.collect.ImmutableMap;
+import hipstershop.Demo.Ads;
+import hipstershop.Demo.AdsRequest;
+import hipstershop.Demo.AdsResponse;
+import io.grpc.ManagedChannel;
+import io.grpc.ManagedChannelBuilder;
+import io.grpc.Server;
+import io.grpc.ServerBuilder;
+import io.grpc.StatusRuntimeException;
+import io.grpc.stub.StreamObserver;
+import io.opencensus.common.Duration;
+import io.opencensus.common.Scope;
+import io.opencensus.contrib.grpc.metrics.RpcViews;
+import io.opencensus.exporter.stats.prometheus.PrometheusStatsCollector;
+import io.opencensus.exporter.trace.logging.LoggingTraceExporter;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsConfiguration;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsExporter;
+import io.opencensus.exporter.trace.stackdriver.StackdriverTraceConfiguration;
+import io.opencensus.exporter.trace.stackdriver.StackdriverTraceExporter;
+import io.opencensus.trace.AttributeValue;
+import io.opencensus.trace.Span;
+import io.opencensus.trace.SpanBuilder;
+import io.opencensus.trace.Status.CanonicalCode;
+import io.opencensus.trace.Tracer;
+import io.opencensus.trace.Tracing;
+import io.opencensus.trace.samplers.Samplers;
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.annotation.Nullable;
+
+/** A simple client that requests a greeting from the {@link AdsServiceClient}. */
+public class AdsServiceClient {
+  private static final Logger logger = Logger.getLogger(AdsServiceClient.class.getName());
+
+  private static final Tracer tracer = Tracing.getTracer();
+
+  private final ManagedChannel channel;
+  private final hipstershop.AdsServiceGrpc.AdsServiceBlockingStub blockingStub;
+
+  /** Construct client connecting to HelloWorld server at {@code host:port}. */
+  public AdsServiceClient(String host, int port) {
+    this(
+        ManagedChannelBuilder.forAddress(host, port)
+            // Channels are secure by default (via SSL/TLS). For the example we disable TLS to avoid
+            // needing certificates.
+            .usePlaintext(true)
+            .build());
+  }
+
+  /** Construct client for accessing RouteGuide server using the existing channel. */
+  AdsServiceClient(ManagedChannel channel) {
+    this.channel = channel;
+    blockingStub = hipstershop.AdsServiceGrpc.newBlockingStub(channel);
+  }
+
+  public void shutdown() throws InterruptedException {
+    channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
+  }
+
+  /** Say hello to server. */
+  public void getAds(String contextKey) {
+    logger.info("Get Ads with context " + contextKey + " ...");
+    AdsRequest request = AdsRequest.newBuilder().addContextKeys(contextKey).build();
+    AdsResponse response;
+
+    SpanBuilder spanBuilder =
+        tracer.spanBuilder("AdsClient").setRecordEvents(true).setSampler(Samplers.alwaysSample());
+    try (Scope scope = spanBuilder.startScopedSpan()) {
+      tracer.getCurrentSpan().addAnnotation("Getting Ads");
+      response = blockingStub.getAds(request);
+      tracer.getCurrentSpan().addAnnotation("Received response from Ads Service.");
+    } catch (StatusRuntimeException e) {
+      tracer
+          .getCurrentSpan()
+          .setStatus(
+              CanonicalCode.valueOf(e.getStatus().getCode().name())
+                  .toStatus()
+                  .withDescription(e.getMessage()));
+      logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());
+      return;
+    }
+    for(Ads ads: response.getAdsList()) {
+      logger.info("Ads: " + ads.getText());
+    }
+  }
+
+  static int getPortOrDefaultFromArgs(String[] args, int index, int defaultPort) {
+    int portNumber = defaultPort;
+    if (index < args.length) {
+      try {
+        portNumber = Integer.parseInt(args[index]);
+      } catch (NumberFormatException e) {
+        logger.warning(
+            String.format("Port %s is invalid, use default port %d.", args[index], defaultPort));
+      }
+    }
+    return portNumber;
+  }
+
+
+  static String getStringOrDefaultFromArgs(
+      String[] args, int index, @Nullable String defaultString) {
+    String s = defaultString;
+    if (index < args.length) {
+      s = args[index];
+    }
+    return s;
+  }
+
+  /**
+   * Greet server. If provided, the first element of {@code args} is the name to use in the
+   * greeting.
+   */
+  public static void main(String[] args) throws IOException, InterruptedException {
+    // Add final keyword to pass checkStyle.
+    final String contextKeys = getStringOrDefaultFromArgs(args, 0, "camera");
+    final String host = getStringOrDefaultFromArgs(args, 1, "localhost");
+    final int serverPort = getPortOrDefaultFromArgs(args, 2, 9555);
+    final String cloudProjectId = getStringOrDefaultFromArgs(args, 3, null);
+    //final int zPagePort = getPortOrDefaultFromArgs(args, 4, 3001);
+
+    // Registers all RPC views.
+    RpcViews.registerAllViews();
+
+
+    // Registers logging trace exporter.
+    LoggingTraceExporter.register();
+
+    // Registers Stackdriver exporters.
+    if (cloudProjectId != null) {
+      StackdriverTraceExporter.createAndRegister(
+          StackdriverTraceConfiguration.builder().setProjectId(cloudProjectId).build());
+      StackdriverStatsExporter.createAndRegister(
+          StackdriverStatsConfiguration.builder()
+              .setProjectId(cloudProjectId)
+              .setExportInterval(Duration.create(15, 0))
+              .build());
+    }
+
+    // Register Prometheus exporters and export metrics to a Prometheus HTTPServer.
+    //PrometheusStatsCollector.createAndRegister();
+
+    AdsServiceClient client = new AdsServiceClient(host, serverPort);
+    try {
+      client.getAds(contextKeys);
+    } finally {
+      client.shutdown();
+    }
+
+    logger.info("Exiting AdsServiceClient...");
+  }
+}

src/adsservice/src/main/proto/demo.proto

@@ -0,0 +1 @@
+../../../../../pb/demo.proto