Auto-validation for tracing sample.

.github/workflows/validate.yml

@@ -112,6 +112,10 @@ jobs:
         working-directory: ./examples
         run: |
           mm.py ./src/main/java/io/dapr/examples/invoke/grpc/README.md
+      - name: Validate tracing example
+        working-directory: ./examples
+        run: |
+          mm.py ./src/main/java/io/dapr/examples/tracing/README.md
       - name: Validate expection handling example
         working-directory: ./examples
         run: |

examples/pom.xml

@@ -74,6 +74,11 @@
       <artifactId>spring-boot-autoconfigure</artifactId>
       <version>2.3.5.RELEASE</version>
     </dependency>
+    <dependency>
+      <groupId>com.jayway.jsonpath</groupId>
+      <artifactId>json-path</artifactId>
+      <version>2.4.0</version>
+    </dependency>
     <dependency>
       <groupId>io.opentelemetry</groupId>
       <artifactId>opentelemetry-sdk</artifactId>

examples/src/main/java/io/dapr/examples/tracing/InvokeClient.java

@@ -66,18 +66,15 @@ public static void main(String[] args) throws Exception {
               }).subscriberContext(getReactorContext()).block();
         }
       }
-
-      // This is an example, so for simplicity we are just exiting here.
-      // Normally a dapr app would be a web service and not exit main.
-      System.out.println("Done");
     }
     span.end();
     shutdown();
+    System.out.println("Done");
   }
 
-  private static void shutdown() {
+  private static void shutdown() throws Exception {
     OpenTelemetrySdk.getGlobalTracerManagement().shutdown();
+    Validation.validate();
   }
 
-
 }

examples/src/main/java/io/dapr/examples/tracing/README.md

@@ -126,10 +126,19 @@ The instrumentation for the service happens via the `OpenTelemetryIterceptor` cl
 
 Use the follow command to execute the service:
 
-```sh
+<!-- STEP
+name: Run demo service
+expected_stdout_lines:
+background: true
+sleep: 20
+-->
+
+```bash
 dapr run --app-id tracingdemo --app-port 3000 -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.tracing.TracingDemoService -p 3000
 ```
 
+<!-- END_STEP -->
+
 Once running, the TracingDemoService is now ready to be invoked by Dapr.
 
 ### Running the Demo middle service app
@@ -208,10 +217,19 @@ public class OpenTelemetryConfig {
 
 Use the follow command to execute the service:
 
-```sh
+<!-- STEP
+name: Run proxy service
+expected_stdout_lines:
+background: true
+sleep: 20
+-->
+
+```bash
 dapr run --app-id tracingdemoproxy --app-port 3001   -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.tracing.TracingDemoService -p 3001
 ```
 
+<!-- END_STEP -->
+
 ### Running the InvokeClient app
 
 This sample code uses the Dapr SDK for invoking two remote methods (`proxy_echo` and `proxy_sleep`). It is also instrumented with OpenTelemetry. See the code snippet below:
@@ -247,13 +265,10 @@ private static final String SERVICE_APP_ID = "tracingdemoproxy";
             }).subscriberContext(getReactorContext()).block();
         }
       }
-
-      // This is an example, so for simplicity we are just exiting here.
-      // Normally a dapr app would be a web service and not exit main.
-      System.out.println("Done");
     }
     span.end();
     shutdown();
+    System.out.println("Done");
   }
 ///...
 }
@@ -262,9 +277,21 @@ private static final String SERVICE_APP_ID = "tracingdemoproxy";
 The class knows the app id for the remote application. It uses `invokeMethod` method to invoke API calls on the service endpoint. The request object includes an instance of `io.opentelemetry.context.Context` for the proper tracing headers to be propagated.
 
 Execute the follow script in order to run the InvokeClient example, passing two messages for the remote method:
-```sh
+
+<!-- STEP
+name: Run demo client
+expected_stdout_lines:
+  - '== APP == Done'
+background: true
+sleep: 20
+-->
+
+```bash
 dapr run -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.tracing.InvokeClient "message one" "message two"
 ```
+
+<!-- END_STEP -->
+
 Open the `tracingdemo` console and check the output as follows:
 
 ```txt

examples/src/main/java/io/dapr/examples/tracing/Validation.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) Microsoft Corporation and Dapr Contributors.
+ * Licensed under the MIT License.
+ */
+
+package io.dapr.examples.tracing;
+
+import com.jayway.jsonpath.DocumentContext;
+import com.jayway.jsonpath.JsonPath;
+import net.minidev.json.JSONArray;
+import okhttp3.HttpUrl;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+
+/**
+ * Class used to verify that traces are present as expected.
+ */
+final class Validation {
+
+  private static final OkHttpClient HTTP_CLIENT = new OkHttpClient();
+
+  public static final String JSONPATH_PROXY_ECHO_SPAN_ID =
+      "$..[?(@.parentId=='%s' && @.name=='calllocal/tracingdemoproxy/proxy_echo')]['id']";
+
+  public static final String JSONPATH_ECHO_SPAN_ID =
+      "$..[?(@.parentId=='%s' && @.name=='calllocal/tracingdemo/echo')]['id']";
+
+  public static final String JSONPATH_PROXY_SLEEP_SPAN_ID =
+      "$..[?(@.parentId=='%s' && @.duration > 1000000 && @.name=='calllocal/tracingdemoproxy/proxy_sleep')]['id']";
+
+  public static final String JSONPATH_SLEEP_SPAN_ID =
+      "$..[?(@.parentId=='%s' && @.duration > 1000000 && @.name=='calllocal/tracingdemo/sleep')]['id']";
+
+  static void validate() throws Exception {
+    // Must wait for some time to make sure Zipkin receives all spans.
+    Thread.sleep(5000);
+    HttpUrl.Builder urlBuilder = new HttpUrl.Builder();
+    urlBuilder.scheme("http")
+        .host("localhost")
+        .port(9411);
+    urlBuilder.addPathSegments("api/v2/traces");
+    Request.Builder requestBuilder = new Request.Builder()
+        .url(urlBuilder.build());
+    requestBuilder.method("GET", null);
+
+    Request request = requestBuilder.build();
+
+    Response response = HTTP_CLIENT.newCall(request).execute();
+    DocumentContext documentContext = JsonPath.parse(response.body().string());
+    String mainSpanId = readOne(documentContext, "$..[?(@.name == \"example's main\")]['id']").toString();
+
+    // Validate echo
+    assertCount(documentContext,
+        String.format(JSONPATH_PROXY_ECHO_SPAN_ID, mainSpanId),
+        2);
+    String proxyEchoSpanId = readOne(documentContext,
+        String.format(JSONPATH_PROXY_ECHO_SPAN_ID, mainSpanId))
+        .toString();
+    String proxyEchoSpanId2 = readOne(documentContext,
+        String.format(JSONPATH_PROXY_ECHO_SPAN_ID, proxyEchoSpanId))
+        .toString();
+    readOne(documentContext,
+        String.format(JSONPATH_ECHO_SPAN_ID, proxyEchoSpanId2));
+
+    // Validate sleep
+    assertCount(documentContext,
+        String.format(JSONPATH_PROXY_SLEEP_SPAN_ID, mainSpanId),
+        2);
+    String proxySleepSpanId = readOne(documentContext,
+        String.format(JSONPATH_PROXY_SLEEP_SPAN_ID, mainSpanId))
+        .toString();
+    String proxySleepSpanId2 = readOne(documentContext,
+        String.format(JSONPATH_PROXY_SLEEP_SPAN_ID, proxySleepSpanId))
+        .toString();
+    readOne(documentContext,
+        String.format(JSONPATH_SLEEP_SPAN_ID, proxySleepSpanId2));
+  }
+
+  private static Object readOne(DocumentContext documentContext, String path) {
+    JSONArray arr = documentContext.read(path);
+    if (arr.size() == 0) {
+      throw new RuntimeException("No record found for " + path);
+    }
+
+    return arr.get(0);
+  }
+
+  private static void assertCount(DocumentContext documentContext, String path, int expectedCount) {
+    JSONArray arr = documentContext.read(path);
+    if (arr.size() != expectedCount) {
+      throw new RuntimeException(
+          String.format("Unexpected count %d vs expected %d for %s", arr.size(), expectedCount, path));
+    }
+  }
+
+}