Azure Functions support

azurefunctions/build.gradle

@@ -0,0 +1,25 @@
+plugins {
+    id 'java-library'
+    id 'maven-publish'
+}
+
+group 'com.microsoft.durabletask'
+version = '0.1.0-SNAPSHOT'
+archivesBaseName = 'durabletask-azurefunctions'
+
+def protocVersion = '3.12.0'
+
+dependencies {
+    api project(':sdk')
+    implementation group: 'com.microsoft.azure.functions', name: 'azure-functions-java-library', version: '1.4.2'
+    implementation "com.google.protobuf:protobuf-java:${protocVersion}"
+}
+
+publishing {
+    publications {
+        mavenPublication(MavenPublication) {
+            artifactId = archivesBaseName
+            from components.java
+        }
+    }
+}

azurefunctions/src/main/java/com/microsoft/durabletask/azurefunctions/DurableActivityTrigger.java

@@ -0,0 +1,67 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.durabletask.azurefunctions;
+
+import com.microsoft.azure.functions.annotation.CustomBinding;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * <p>
+ * Azure Functions attribute for binding a function parameter to a Durable Task activity input.
+ * </p><p>
+ * The following is an example of an activity trigger function that accepts a String input and returns a String output.
+ * </p>
+ * <pre>
+ * {@literal @}FunctionName("SayHello")
+ * public String sayHello(
+ *         {@literal @}DurableActivityTrigger(name = "name") String name,
+ *         final ExecutionContext context) {
+ *     context.getLogger().info("Saying hello to: " + name);
+ *     return String.format("Hello %s!", name);
+ * }
+ * </pre>
+ * 
+ * @since 2.0.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+@CustomBinding(direction = "in", name = "", type = "activityTrigger")
+public @interface DurableActivityTrigger {
+    /**
+     * <p>The name of the activity function.</p>
+     * <p>If not specified, the function name is used as the name of the activity.</p>
+     * <p>This property supports binding parameters.</p>
+     * 
+     * @return The name of the orchestrator function.
+     */
+    String activity() default "";
+
+    /**
+     * The variable name used in function.json.
+     * 
+     * @return The variable name used in function.json.
+     */
+    String name();
+
+    /**
+     * <p>
+     * Defines how Functions runtime should treat the parameter value. Possible values are:
+     * </p>
+     * <ul>
+     * <li>"": get the value as a string, and try to deserialize to actual parameter type like POJO</li>
+     * <li>string: always get the value as a string</li>
+     * <li>binary: get the value as a binary data, and try to deserialize to actual parameter type byte[]</li>
+     * </ul>
+     * 
+     * @return The dataType which will be used by the Functions runtime.
+     */
+    String dataType() default "";
+}

azurefunctions/src/main/java/com/microsoft/durabletask/azurefunctions/DurableClientContext.java

@@ -0,0 +1,103 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.durabletask.azurefunctions;
+
+import com.microsoft.azure.functions.HttpRequestMessage;
+import com.microsoft.azure.functions.HttpResponseMessage;
+
+import com.microsoft.azure.functions.HttpStatus;
+import com.microsoft.durabletask.DurableTaskClient;
+import com.microsoft.durabletask.DurableTaskGrpcClient;
+
+import java.io.UnsupportedEncodingException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * The binding value type for the {@literal @}DurableClientInput parameter.
+ */
+public class DurableClientContext {
+    // These fields are populated via GSON deserialization by the Functions Java worker.
+    private String rpcBaseUrl;
+    private String taskHubName;
+    private String requiredQueryStringParameters;
+
+    /**
+     * Gets the name of the client binding's task hub.
+     *
+     * @return the name of the client binding's task hub.
+     */
+    public String getTaskHubName() {
+        return this.taskHubName;
+    }
+
+    /**
+     * Gets the durable task client associated with the current function invocation.
+     *
+     * @return the Durable Task client object associated with the current function invocation.
+     */
+    public DurableTaskClient getClient() {
+        if (this.rpcBaseUrl == null || this.rpcBaseUrl.length() == 0) {
+            throw new IllegalStateException("The client context wasn't populated with an RPC base URL!");
+        }
+
+        URL rpcURL;
+        try {
+            rpcURL = new URL(this.rpcBaseUrl);
+        } catch (MalformedURLException ex) {
+            throw new IllegalStateException("The client context RPC base URL was invalid!", ex);
+        }
+
+        return DurableTaskGrpcClient.newBuilder().forPort(rpcURL.getPort()).build();
+    }
+
+    public HttpResponseMessage createCheckStatusResponse(HttpRequestMessage<?> request, String instanceId) {
+        // TODO: To better support scenarios involving proxies or application gateways, this
+        //       code should take the X-Forwarded-Host, X-Forwarded-Proto, and Forwarded HTTP
+        //       request headers into consideration and generate the base URL accordingly.
+        //       More info: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Forwarded.
+        //       One potential workaround is to set ASPNETCORE_FORWARDEDHEADERS_ENABLED to true.
+        String baseUrl = request.getUri().getScheme() + "://" + request.getUri().getAuthority();
+        String encodedInstanceId;
+        try {
+            encodedInstanceId = URLEncoder.encode(instanceId, StandardCharsets.UTF_8.toString());
+        } catch (UnsupportedEncodingException ex) {
+            throw new IllegalArgumentException("Failed to encode the instance ID: " + instanceId, ex);
+        }
+
+        String instanceStatusURL = baseUrl + "/runtime/webhooks/durabletask/instances/" + encodedInstanceId;
+
+        // Construct the response as an HTTP 201 with a JSON object payload
+        return request.createResponseBuilder(HttpStatus.CREATED)
+                .header("Location", instanceStatusURL + "?" + this.requiredQueryStringParameters)
+                .header("Content-Type", "application/json")
+                .body(new HttpCreateCheckStatusResponse(
+                        instanceId,
+                        instanceStatusURL,
+                        this.requiredQueryStringParameters))
+                .build();
+            }
+
+    private static class HttpCreateCheckStatusResponse {
+        // These fields are serialized to JSON
+        public final String id;
+        public final String purgeHistoryDeleteUri;
+        public final String sendEventPostUri;
+        public final String statusQueryGetUri;
+        public final String terminatePostUri;
+
+        public HttpCreateCheckStatusResponse(
+                String instanceId,
+                String instanceStatusURL,
+                String requiredQueryStringParameters) {
+            this.id = instanceId;
+            this.purgeHistoryDeleteUri = instanceStatusURL + "?" + requiredQueryStringParameters;
+            this.sendEventPostUri = instanceStatusURL + "/raiseEvent/{eventName}?" + requiredQueryStringParameters;
+            this.statusQueryGetUri = instanceStatusURL + "?" + requiredQueryStringParameters;
+            this.terminatePostUri = instanceStatusURL + "/terminate?reason={text}&" + requiredQueryStringParameters;
+        }
+    }
+}

azurefunctions/src/main/java/com/microsoft/durabletask/azurefunctions/DurableClientInput.java

@@ -0,0 +1,82 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.durabletask.azurefunctions;
+
+import com.microsoft.azure.functions.annotation.CustomBinding;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * <p>
+ * Azure Functions attribute for binding a function parameter to a {@literal @}DurableClientContext object.
+ * </p><p>
+ * The following is an example of an HTTP-trigger function that uses this input binding to start a new
+ * orchestration instance.
+ * </p>
+ * <pre>
+ * {@literal @}FunctionName("StartHelloCities")
+ * public HttpResponseMessage startHelloCities(
+ *         {@literal @}HttpTrigger(name = "request", methods = {HttpMethod.GET, HttpMethod.POST}, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Optional<String>> request,
+ *         {@literal @}DurableClientInput(name = "durableContext") DurableClientContext durableContext,
+ *         final ExecutionContext context) {
+ * 
+ *     DurableTaskClient client = durableContext.getClient();
+ *     String instanceId = client.scheduleNewOrchestrationInstance("HelloCities");
+ *     context.getLogger().info("Created new Java orchestration with instance ID = " + instanceId);
+ *     return durableContext.createCheckStatusResponse(request, instanceId);
+ * }
+ * </pre>
+ * 
+ * @since 2.0.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+@CustomBinding(direction = "in", name = "", type = "durableClient")
+public @interface DurableClientInput {
+    /**
+     * The variable name used in function.json.
+     * 
+     * @return The variable name used in function.json.
+     */
+    String name();
+
+    /**
+     * <p>
+     * Defines how Functions runtime should treat the parameter value. Possible values are:
+     * </p>
+     * <ul>
+     * <li>"": get the value as a string, and try to deserialize to actual parameter type like POJO</li>
+     * <li>string: always get the value as a string</li>
+     * <li>binary: get the value as a binary data, and try to deserialize to actual parameter type byte[]</li>
+     * </ul>
+     * 
+     * @return The dataType which will be used by the Functions runtime.
+     */
+    String dataType() default "";
+
+    /**
+     * <p>
+     * Optional. The name of the task hub in which the orchestration data lives.
+     * </p>
+     * <p>
+     * If not specified, the task hub name used by this binding will be the value specified in host.json.
+     * If a task hub name is not configured in host.json and if the function app is running in the 
+     * Azure Functions hosted service, then task hub name is derived from the function app's name.
+     * Otherwise, a constant value is used for the task hub name.
+     * </p>
+     * <p>
+     * In general, you should <i>not</i> set a value for the task hub name here unless you intend to configure
+     * the client to interact with orchestrations in another app.
+     * </p>
+     * 
+     * @return The task hub name to use for the client.
+     */
+    String taskHub() default "";
+}

azurefunctions/src/main/java/com/microsoft/durabletask/azurefunctions/DurableOrchestrationTrigger.java

@@ -0,0 +1,70 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.durabletask.azurefunctions;
+
+import com.microsoft.azure.functions.annotation.CustomBinding;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * <p>
+ * Azure Functions attribute for binding a function parameter to a Durable Task orchestration request.
+ * </p><p>
+ * The following is an example of an orchestrator function that calls three activity functions in sequence.
+ * </p>
+ * <pre>
+ * {@literal @}FunctionName("HelloCities")
+ * public String helloCitiesOrchestrator(
+ *         {@literal @}DurableOrchestrationTrigger(name = "orchestratorRequestProtoBytes") String orchestratorRequestProtoBytes) {
+ *     return OrchestrationRunner.loadAndRun(orchestratorRequestProtoBytes, ctx -> {
+ *         String result = "";
+ *         result += ctx.callActivity("SayHello", "Tokyo", String.class).get() + ", ";
+ *         result += ctx.callActivity("SayHello", "London", String.class).get() + ", ";
+ *         result += ctx.callActivity("SayHello", "Seattle", String.class).get();
+ *         return result;
+ *     });
+ * }
+ * </pre>
+ * 
+ * @since 2.0.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+@CustomBinding(direction = "in", name = "", type = "orchestrationTrigger")
+public @interface DurableOrchestrationTrigger {
+    /**
+     * <p>The name of the orchestrator function.</p>
+     * <p>If not specified, the function name is used as the name of the orchestration.</p>
+     * <p>This property supports binding parameters.</p>
+     * @return The name of the orchestrator function.
+     */
+    String orchestration() default "";
+
+    /**
+     * The variable name used in function.json.
+     * 
+     * @return The variable name used in function.json.
+     */
+    String name();
+
+    /**
+     * <p>
+     * Defines how Functions runtime should treat the parameter value. Possible values are:
+     * </p>
+     * <ul>
+     * <li>"": get the value as a string, and try to deserialize to actual parameter type like POJO</li>
+     * <li>string: always get the value as a string</li>
+     * <li>binary: get the value as a binary data, and try to deserialize to actual parameter type byte[]</li>
+     * </ul>
+     * 
+     * @return The dataType which will be used by the Functions runtime.
+     */
+    String dataType() default "string";
+}

build.gradle

@@ -1,5 +1,6 @@
 subprojects {
   repositories {
+    mavenLocal()
     mavenCentral()
   }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

sdk/build.gradle

@@ -1,13 +1,14 @@
 plugins {
-    id 'java'
+    id 'java-library'
     id 'com.google.protobuf' version '0.8.16'
     // Generate IntelliJ IDEA's .idea & .iml project files
     id 'idea'
+    id 'maven-publish'
 }
 
-group 'com.microsoft'
+group 'com.microsoft.durabletask'
 version = '0.1.0'
-archivesBaseName = 'durabletask'
+archivesBaseName = 'durabletask-sdk'
 
 def grpcVersion = '1.38.0'
 def protocVersion = '3.12.0'
@@ -75,3 +76,11 @@ task integrationTest(type: Test) {
     testLogging.showStandardStreams = true
 }
 
+publishing {
+    publications {
+        mavenPublication(MavenPublication) {
+            artifactId = archivesBaseName
+            from components.java
+        }
+    }
+}