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<title>Spring Cloud Function</title><link rel="stylesheet" type="text/css" href="css/manual-singlepage.css"><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div lang="en" class="book"><div class="titlepage"><div><div><h1 class="title"><a name="d0e3"></a>Spring Cloud Function</h1></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="preface"><a href="#d0e9"></a></span></dt><dt><span class="chapter"><a href="#_introduction">1. Introduction</a></span></dt><dt><span class="chapter"><a href="#_getting_started">2. Getting Started</a></span></dt><dt><span class="chapter"><a href="#_building_and_running_a_function">3. Building and Running a Function</a></span></dt><dt><span class="chapter"><a href="#_function_catalog_and_flexible_function_signatures">4. Function Catalog and Flexible Function Signatures</a></span></dt><dd><dl><dt><span class="section"><a href="#_java_8_function_support">4.1. Java 8 function support</a></span></dt><dt><span class="section"><a href="#_kotlin_lambda_support">4.2. Kotlin Lambda support</a></span></dt></dl></dd><dt><span class="chapter"><a href="#_standalone_web_applications">5. Standalone Web Applications</a></span></dt><dt><span class="chapter"><a href="#_standalone_streaming_applications">6. Standalone Streaming Applications</a></span></dt><dt><span class="chapter"><a href="#_deploying_a_packaged_function">7. Deploying a Packaged Function</a></span></dt><dt><span class="chapter"><a href="#_dynamic_compilation">8. Dynamic Compilation</a></span></dt><dt><span class="chapter"><a href="#_serverless_platform_adapters">9. Serverless Platform Adapters</a></span></dt><dd><dl><dt><span class="section"><a href="#_aws_lambda">9.1. AWS Lambda</a></span></dt><dd><dl><dt><span class="section"><a href="#_introduction_2">9.1.1. Introduction</a></span></dt><dt><span class="section"><a href="#_notes_on_jar_layout">9.1.2. Notes on JAR Layout</a></span></dt><dt><span class="section"><a href="#_upload">9.1.3. Upload</a></span></dt><dt><span class="section"><a href="#_platfom_specific_features">9.1.4. Platfom Specific Features</a></span></dt><dd><dl><dt><span class="section"><a href="#_http_and_api_gateway">HTTP and API Gateway</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="#_azure_functions">9.2. Azure Functions</a></span></dt><dd><dl><dt><span class="section"><a href="#_notes_on_jar_layout_2">9.2.1. Notes on JAR Layout</a></span></dt><dt><span class="section"><a href="#_json_configuration">9.2.2. JSON Configuration</a></span></dt><dt><span class="section"><a href="#_build">9.2.3. Build</a></span></dt><dt><span class="section"><a href="#_running_the_sample">9.2.4. Running the sample</a></span></dt></dl></dd><dt><span class="section"><a href="#_apache_openwhisk">9.3. Apache Openwhisk</a></span></dt><dd><dl><dt><span class="section"><a href="#_quick_start">9.3.1. Quick Start</a></span></dt></dl></dd></dl></dd></dl></div><div class="preface"><div class="titlepage"><div><div><h1 class="title"><a name="d0e9" href="#d0e9"></a></h1></div></div></div><p>Mark Fisher, Dave Syer, Oleg Zhurakousky</p><p></p></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="_introduction" href="#_introduction"></a>1. Introduction</h1></div></div></div><p>Spring Cloud Function is a project with the following high-level goals:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">Promote the implementation of business logic via functions.</li><li class="listitem">Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.</li><li class="listitem">Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).</li><li class="listitem">Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.</li></ul></div><p>It abstracts away all of the transport details and
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<title>Spring Cloud Function</title><link rel="stylesheet" type="text/css" href="css/manual-singlepage.css"><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div lang="en" class="book"><div class="titlepage"><div><div><h1 class="title"><a name="d0e3"></a>Spring Cloud Function</h1></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="preface"><a href="#d0e9"></a></span></dt><dt><span class="chapter"><a href="#_introduction">1. Introduction</a></span></dt><dt><span class="chapter"><a href="#_getting_started">2. Getting Started</a></span></dt><dt><span class="chapter"><a href="#_building_and_running_a_function">3. Building and Running a Function</a></span></dt><dt><span class="chapter"><a href="#_function_catalog_and_flexible_function_signatures">4. Function Catalog and Flexible Function Signatures</a></span></dt><dd><dl><dt><span class="section"><a href="#_java_8_function_support">4.1. Java 8 function support</a></span></dt><dt><span class="section"><a href="#_kotlin_lambda_support">4.2. Kotlin Lambda support</a></span></dt></dl></dd><dt><span class="chapter"><a href="#_standalone_web_applications">5. Standalone Web Applications</a></span></dt><dt><span class="chapter"><a href="#_standalone_streaming_applications">6. Standalone Streaming Applications</a></span></dt><dt><span class="chapter"><a href="#_deploying_a_packaged_function">7. Deploying a Packaged Function</a></span></dt><dt><span class="chapter"><a href="#_dynamic_compilation">8. Dynamic Compilation</a></span></dt><dt><span class="chapter"><a href="#_serverless_platform_adapters">9. Serverless Platform Adapters</a></span></dt><dd><dl><dt><span class="section"><a href="#_aws_lambda">9.1. AWS Lambda</a></span></dt><dd><dl><dt><span class="section"><a href="#_introduction_2">9.1.1. Introduction</a></span></dt><dt><span class="section"><a href="#_notes_on_jar_layout">9.1.2. Notes on JAR Layout</a></span></dt><dt><span class="section"><a href="#_upload">9.1.3. Upload</a></span></dt><dt><span class="section"><a href="#_platfom_specific_features">9.1.4. Platfom Specific Features</a></span></dt><dd><dl><dt><span class="section"><a href="#_http_and_api_gateway">HTTP and API Gateway</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="#_azure_functions">9.2. Azure Functions</a></span></dt><dd><dl><dt><span class="section"><a href="#_notes_on_jar_layout_2">9.2.1. Notes on JAR Layout</a></span></dt><dt><span class="section"><a href="#_build">9.2.2. Build</a></span></dt><dt><span class="section"><a href="#_running_the_sample">9.2.3. Running the sample</a></span></dt></dl></dd><dt><span class="section"><a href="#_apache_openwhisk">9.3. Apache Openwhisk</a></span></dt><dd><dl><dt><span class="section"><a href="#_quick_start">9.3.1. Quick Start</a></span></dt></dl></dd></dl></dd></dl></div><div class="preface"><div class="titlepage"><div><div><h1 class="title"><a name="d0e9" href="#d0e9"></a></h1></div></div></div><p>Mark Fisher, Dave Syer, Oleg Zhurakousky</p><p></p></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="_introduction" href="#_introduction"></a>1. Introduction</h1></div></div></div><p>Spring Cloud Function is a project with the following high-level goals:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">Promote the implementation of business logic via functions.</li><li class="listitem">Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.</li><li class="listitem">Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).</li><li class="listitem">Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.</li></ul></div><p>It abstracts away all of the transport details and
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infrastructure, allowing the developer to keep all the familiar tools
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and processes, and focus firmly on business logic.</p><p>Here’s a complete, executable, testable Spring Boot application
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(implementing a simple string manipulation):</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@SpringBootApplication</span></em>
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@@ -124,27 +124,17 @@ has its own Spring Cloud Function adapter. And
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<a class="link" href="https://github.com/projectriff/java-function-invoker" target="_top">Java Function
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Invoker</a> acts natively is an adapter for Spring Cloud Function jars.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_aws_lambda" href="#_aws_lambda"></a>9.1 AWS Lambda</h2></div></div></div><p>The <a class="link" href="https://aws.amazon.com/" target="_top">AWS</a> adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_introduction_2" href="#_introduction_2"></a>9.1.1 Introduction</h3></div></div></div><p>The adapter has a couple of generic request handlers that you can use. The most generic is <code class="literal">SpringBootStreamHandler</code>, which uses a Jackson <code class="literal">ObjectMapper</code> provided by Spring Boot to serialize and deserialize the objects in the function. There is also a <code class="literal">SpringBootRequestHandler</code> which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).</p><p>If your app has more than one <code class="literal">@Bean</code> of type <code class="literal">Function</code> etc. then you can choose the one to use by configuring <code class="literal">function.name</code> (e.g. as <code class="literal">FUNCTION_NAME</code> environment variable in AWS). The functions are extracted from the Spring Cloud <code class="literal">FunctionCatalog</code> (searching first for <code class="literal">Function</code> then <code class="literal">Consumer</code> and finally <code class="literal">Supplier</code>).</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_notes_on_jar_layout" href="#_notes_on_jar_layout"></a>9.1.2 Notes on JAR Layout</h3></div></div></div><p>You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be shaded, but a Spring Boot standalone application does not, so you can run the same app using 2 separate jars (as per the sample). The sample app creates 2 jar files, one with an <code class="literal">aws</code> classifier for deploying in Lambda, and one executable (thin) jar that includes <code class="literal">spring-cloud-function-web</code> at runtime. Spring Cloud Function will try and locate a "main class" for you from the JAR file manifest, using the <code class="literal">Start-Class</code> attribute (which will be added for you by the Spring Boot tooling if you use the starter parent). If there is no <code class="literal">Start-Class</code> in your manifest you can use an environment variable <code class="literal">MAIN_CLASS</code> when you deploy the function to AWS.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_upload" href="#_upload"></a>9.1.3 Upload</h3></div></div></div><p>Build the sample under <code class="literal">spring-cloud-function-samples/function-sample-aws</code> and upload the <code class="literal">-aws</code> jar file to Lambda. The handler can be <code class="literal">example.Handler</code> or <code class="literal">org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler</code> (FQN of the class, <span class="emphasis"><em>not</em></span> a method reference, although Lambda does accept method references).</p><pre class="screen">./mvnw -U clean package</pre><p>Using the AWS command line tools it looks like this:</p><pre class="screen">aws lambda create-function --function-name Uppercase --role arn:aws:iam::[USERID]:role/service-role/[ROLE] --zip-file fileb://function-sample-aws/target/function-sample-aws-2.0.0.BUILD-SNAPSHOT-aws.jar --handler org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler --description "Spring Cloud Function Adapter Example" --runtime java8 --region us-east-1 --timeout 30 --memory-size 1024 --publish</pre><p>The input type for the function in the AWS sample is a Foo with a single property called "value". So you would need this to test it:</p><pre class="screen">{
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"value": "test"
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}</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_platfom_specific_features" href="#_platfom_specific_features"></a>9.1.4 Platfom Specific Features</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="_http_and_api_gateway" href="#_http_and_api_gateway"></a>HTTP and API Gateway</h4></div></div></div><p>AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring <code class="literal">Message</code>. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type <code class="literal">Function<Message<S>,Message<T>></code>, where <code class="literal">S</code> and <code class="literal">T</code> are your business data types. If there is more than one bean of type <code class="literal">Function</code> you may also need to configure the Spring Boot property <code class="literal">function.name</code> to be the name of the target bean (e.g. use <code class="literal">FUNCTION_NAME</code> as an environment variable).</p><p>The supported AWS services and generic handler types are listed below:</p><div class="informaltable"><table style="border-collapse: collapse;border-top: 0.5pt solid ; border-bottom: 0.5pt solid ; border-left: 0.5pt solid ; border-right: 0.5pt solid ; "><colgroup><col class="col_1"><col class="col_2"><col class="col_3"><col class="col_4"></colgroup><thead><tr><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">Service</th><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">AWS Types</th><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">Generic Handler</th><th style="border-bottom: 0.5pt solid ; " align="left" valign="top"> </th></tr></thead><tbody><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p>API Gateway</p></td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p><code class="literal">APIGatewayProxyRequestEvent</code>, <code class="literal">APIGatewayProxyResponseEvent</code></p></td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p><code class="literal">org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler</code></p></td><td style="border-bottom: 0.5pt solid ; " align="left" valign="top"> </td></tr><tr><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>Kinesis</p></td><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>KinesisEvent</p></td><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler</p></td><td style="" align="left" valign="top"> </td></tr></tbody></table></div><p>For example, to deploy behind an API Gateway, use <code class="literal">--handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler</code> in your AWS command line (in via the UI) and define a <code class="literal">@Bean</code> of type <code class="literal">Function<Message<Foo>,Message<Bar>></code> where <code class="literal">Foo</code> and <code class="literal">Bar</code> are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_azure_functions" href="#_azure_functions"></a>9.2 Azure Functions</h2></div></div></div><p>The <a class="link" href="https://azure.microsoft.com" target="_top">Azure</a> adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The Spring Cloud Function Azure adapter trades the convenience of these annotations for portability of the function implementations. Instead of using the annotations you have to write some JSON by hand (at least for now) to guide the platform to call the right methods in the adapter.</p><p>This project provides an adapter layer for a Spring Cloud Function application onto Azure.
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You can write an app with a single <code class="literal">@Bean</code> of type <code class="literal">Function</code> and it will be deployable in Azure if you get the JAR file laid out right.</p><p>The adapter has a generic HTTP request handler that you can use optionally.
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There is a <code class="literal">AzureSpringBootRequestHandler</code> which you must extend, and provide the input and output types as type parameters (enabling Azure to inspect the class and do the JSON conversions itself).</p><p>If your app has more than one <code class="literal">@Bean</code> of type <code class="literal">Function</code> etc. then you can choose the one to use by configuring <code class="literal">function.name</code>.
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The functions are extracted from the Spring Cloud <code class="literal">FunctionCatalog</code>.</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_notes_on_jar_layout_2" href="#_notes_on_jar_layout_2"></a>9.2.1 Notes on JAR Layout</h3></div></div></div><p>You don’t need the Spring Cloud Function Web at runtime in Azure, so you need to exclude this before you create the JAR you deploy to Azure.
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A function application on Azure has to be shaded, but a Spring Boot standalone application does not, so you can run the same app using 2 separate jars (as per the sample here).
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The sample app creates the shaded jar file, with an <code class="literal">azure</code> classifier for deploying in Azure.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_json_configuration" href="#_json_configuration"></a>9.2.2 JSON Configuration</h3></div></div></div><p>The Azure tooling needs to find some JSON configuration files to tell it how to deploy and integrate the function (e.g. which Java class to use as the entry point, and which triggers to use). Those files can be created with the Maven plugin for a non-Spring function, but the tooling doesn’t work yet with the adapter in its current form. There is an example <code class="literal">function.json</code> in the sample which hooks the function up as an HTTP endpoint:</p><pre class="screen">{
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"scriptFile" : "../function-sample-azure-2.0.0.BUILD-SNAPSHOT-azure.jar",
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"entryPoint" : "example.FooHandler.execute",
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"bindings" : [ {
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"type" : "httpTrigger",
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"name" : "foo",
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"direction" : "in",
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"authLevel" : "anonymous",
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"methods" : [ "get", "post" ]
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}, {
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"type" : "http",
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"name" : "$return",
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"direction" : "out"
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} ],
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"disabled" : false
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}</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_build" href="#_build"></a>9.2.3 Build</h3></div></div></div><pre class="screen">./mvnw -U clean package</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_running_the_sample" href="#_running_the_sample"></a>9.2.4 Running the sample</h3></div></div></div><p>You can run the sample locally, just like the other Spring Cloud Function samples:</p><p></p><p></p><p>and <code class="literal">curl -H "Content-Type: text/plain" localhost:8080/function -d '{"value": "hello foobar"}'</code>.</p><p>You will need the <code class="literal">az</code> CLI app and some node.js fu (see <a class="link" href="https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-java-maven" target="_top">https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-java-maven</a> for more detail). To deploy the function on Azure runtime:</p><pre class="screen">$ az login
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}</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_platfom_specific_features" href="#_platfom_specific_features"></a>9.1.4 Platfom Specific Features</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="_http_and_api_gateway" href="#_http_and_api_gateway"></a>HTTP and API Gateway</h4></div></div></div><p>AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring <code class="literal">Message</code>. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type <code class="literal">Function<Message<S>,Message<T>></code>, where <code class="literal">S</code> and <code class="literal">T</code> are your business data types. If there is more than one bean of type <code class="literal">Function</code> you may also need to configure the Spring Boot property <code class="literal">function.name</code> to be the name of the target bean (e.g. use <code class="literal">FUNCTION_NAME</code> as an environment variable).</p><p>The supported AWS services and generic handler types are listed below:</p><div class="informaltable"><table style="border-collapse: collapse;border-top: 0.5pt solid ; border-bottom: 0.5pt solid ; border-left: 0.5pt solid ; border-right: 0.5pt solid ; "><colgroup><col class="col_1"><col class="col_2"><col class="col_3"><col class="col_4"></colgroup><thead><tr><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">Service</th><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">AWS Types</th><th style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top">Generic Handler</th><th style="border-bottom: 0.5pt solid ; " align="left" valign="top"> </th></tr></thead><tbody><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p>API Gateway</p></td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p><code class="literal">APIGatewayProxyRequestEvent</code>, <code class="literal">APIGatewayProxyResponseEvent</code></p></td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; " align="left" valign="top"><p><code class="literal">org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler</code></p></td><td style="border-bottom: 0.5pt solid ; " align="left" valign="top"> </td></tr><tr><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>Kinesis</p></td><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>KinesisEvent</p></td><td style="border-right: 0.5pt solid ; " align="left" valign="top"><p>org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler</p></td><td style="" align="left" valign="top"> </td></tr></tbody></table></div><p>For example, to deploy behind an API Gateway, use <code class="literal">--handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler</code> in your AWS command line (in via the UI) and define a <code class="literal">@Bean</code> of type <code class="literal">Function<Message<Foo>,Message<Bar>></code> where <code class="literal">Foo</code> and <code class="literal">Bar</code> are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_azure_functions" href="#_azure_functions"></a>9.2 Azure Functions</h2></div></div></div><p>The <a class="link" href="https://azure.microsoft.com" target="_top">Azure</a> adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the <code class="literal">@FunctionName</code> annotation which delegates to a base class method.</p><p>This project provides an adapter layer for a Spring Cloud Function application onto Azure.
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||||
You can write an app with a single <code class="literal">@Bean</code> of type <code class="literal">Function</code> and it will be deployable in Azure if you get the JAR file laid out right.</p><p>There is an <code class="literal">AzureSpringBootRequestHandler</code> which you must extend, and provide the input and output types as annotated method parameters (enabling Azure to inspect the class and create JSON bindings). The base class has two useful methods (<code class="literal">handleRequest</code> and <code class="literal">handleOutput</code>) to which you can delegate the actual function call, so mostly the function will only ever have one line.</p><p>Example:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span> FooHandler <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">extends</span> AzureSpringBootRequestHandler<Foo, Bar> {
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||||
<em><span class="hl-annotation" style="color: gray">@FunctionName("uppercase")</span></em>
|
||||
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> Bar execute(
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||||
<em><span class="hl-annotation" style="color: gray">@HttpTrigger(name = "req", methods = { HttpMethod.GET,
|
||||
HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS)</span></em>
|
||||
Foo foo,
|
||||
ExecutionContext context) {
|
||||
<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">return</span> handleRequest(foo, context);
|
||||
}
|
||||
}</pre><p>This Azure handler will delegate to a <code class="literal">Function<Foo,Bar></code> bean (or a <code class="literal">Function<Publisher<Foo>,Publisher<Bar>></code>). Some Azure triggers (e.g. <code class="literal">@CosmosDBTrigger</code>) result in a input type of <code class="literal">List</code> and in that case you can bind to <code class="literal">List</code> in the Azure handler, or <code class="literal">String</code> (the raw JSON). The <code class="literal">List</code> input delegates to a <code class="literal">Function</code> with input type <code class="literal">Map<String,Object></code>, or <code class="literal">Publisher</code> or <code class="literal">List</code> of the same type. The output of the <code class="literal">Function</code> can be a <code class="literal">List</code> (one-for-one) or a single value (aggregation), and the output binding in the Azure declaration should match.</p><p>If your app has more than one <code class="literal">@Bean</code> of type <code class="literal">Function</code> etc. then you can choose the one to use by configuring <code class="literal">function.name</code>. Or if you make the <code class="literal">@FunctionName</code> in the Azure handler method match the function name it should work that way (also for function apps with multiple functions). The functions are extracted from the Spring Cloud <code class="literal">FunctionCatalog</code> so the default function names are the same as the bean names.</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_notes_on_jar_layout_2" href="#_notes_on_jar_layout_2"></a>9.2.1 Notes on JAR Layout</h3></div></div></div><p>You don’t need the Spring Cloud Function Web at runtime in Azure, so you can exclude this before you create the JAR you deploy to Azure, but it won’t be used if you include it so it doesn’t hurt to leave it in. A function application on Azure is an archive generated by the Maven plugin. The function lives in the JAR file generated by this project. The sample creates it as an executable jar, using the thin layout, so that Azure can find the handler classes. If you prefer you can just use a regular flat JAR file. The dependencies should <span class="strong"><strong>not</strong></span> be included.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_build" href="#_build"></a>9.2.2 Build</h3></div></div></div><pre class="screen">./mvnw -U clean package</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_running_the_sample" href="#_running_the_sample"></a>9.2.3 Running the sample</h3></div></div></div><p>You can run the sample locally, just like the other Spring Cloud Function samples:</p><p></p><p></p><p>and <code class="literal">curl -H "Content-Type: text/plain" localhost:8080/function -d '{"value": "hello foobar"}'</code>.</p><p>You will need the <code class="literal">az</code> CLI app and some node.js fu (see <a class="link" href="https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-java-maven" target="_top">https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-java-maven</a> for more detail). To deploy the function on Azure runtime:</p><pre class="screen">$ az login
|
||||
$ mvn azure-functions:deploy</pre><p>On another terminal try this: <code class="literal">curl <a class="link" href="https://<azure-function-url-from-the-log>/api/uppercase" target="_top">https://<azure-function-url-from-the-log>/api/uppercase</a> -d '{"value": "hello foobar!"}'</code>. Please ensure that you use the right URL for the function above. Alternatively you can test the function in the Azure Dashboard UI (click on the function name, go to the right hand side and click "Test" and to the bottom right, "Run").</p><p>The input type for the function in the Azure sample is a Foo with a single property called "value". So you need this to test it with something like below:</p><pre class="screen">{
|
||||
"value": "foobar"
|
||||
}</pre></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_apache_openwhisk" href="#_apache_openwhisk"></a>9.3 Apache Openwhisk</h2></div></div></div><p>The <a class="link" href="https://openwhisk.apache.org/" target="_top">OpenWhisk</a> adapter is in the form of an executable jar that can be used in a a docker image to be deployed to Openwhisk. The platform works in request-response mode, listening on port 8080 on a specific endpoint, so the adapter is a simple Spring MVC application.</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_quick_start" href="#_quick_start"></a>9.3.1 Quick Start</h3></div></div></div><p>Implement a POF (be sure to use the <code class="literal">functions</code> package):</p><pre class="screen">package functions;
|
||||
|
||||
Reference in New Issue
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