Create azure provider

Author: axel-op

azure-provider/pom.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project>
+    <modelVersion>4.0.0</modelVersion>
+    <packaging>jar</packaging>
+    <name>Azure Functions Provider for Agnostic Serverless Functions</name>
+    <groupId>fr.axelop.agnosticserverlessfunctions</groupId>
+    <artifactId>agnostic-serverless-functions-azure-provider</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <parent>
+        <groupId>fr.axelop.agnosticserverlessfunctions</groupId>
+        <artifactId>agnostic-serverless-functions-providers</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>fr.axelop.agnosticserverlessfunctions</groupId>
+            <artifactId>agnostic-serverless-functions-interfaces</artifactId>
+            <version>${agnostic.serverless.functions.interfaces.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.microsoft.azure.functions</groupId>
+            <artifactId>azure-functions-java-library</artifactId>
+            <version>2.0.1</version>
+        </dependency>
+    </dependencies>
+</project>

azure-provider/src/main/java/fr/axelop/agnosticserverlessfunctions/FunctionInvoker.java

@@ -0,0 +1,59 @@
+package fr.axelop.agnosticserverlessfunctions;
+
+import java.util.Optional;
+import java.util.ServiceLoader;
+import java.util.function.Supplier;
+import java.util.logging.Logger;
+
+import com.microsoft.azure.functions.ExecutionContext;
+import com.microsoft.azure.functions.HttpMethod;
+import com.microsoft.azure.functions.HttpRequestMessage;
+import com.microsoft.azure.functions.HttpResponseMessage;
+import com.microsoft.azure.functions.annotation.AuthorizationLevel;
+import com.microsoft.azure.functions.annotation.FunctionName;
+import com.microsoft.azure.functions.annotation.HttpTrigger;
+
+public class FunctionInvoker {
+
+    private static final HttpRequestMapper requestMapper = new HttpRequestMapper();
+    private static final HttpResponseMapper responseMapper = new HttpResponseMapper();
+    private static final Optional<Handler> optHandler = lookupHandler();
+    private static final Supplier<String> exceptionMessageSupplier = () -> "Implementation of "
+            + Handler.class.getName()
+            + " not found. Make sure that it is referenced as a service under META-INF/services.";
+
+    @FunctionName("handler")
+    public HttpResponseMessage run(
+        @HttpTrigger(
+            name = "httpTrigger",
+            authLevel = AuthorizationLevel.ANONYMOUS,
+            methods = {
+                HttpMethod.CONNECT,
+                HttpMethod.DELETE,
+                HttpMethod.GET,
+                HttpMethod.HEAD,
+                HttpMethod.OPTIONS,
+                HttpMethod.PATCH,
+                HttpMethod.POST,
+                HttpMethod.PUT,
+                HttpMethod.TRACE
+            }
+        )
+        HttpRequestMessage<Optional<String>> request,
+        ExecutionContext context
+    ) throws Exception {
+        final Logger logger = context.getLogger();
+        if (optHandler.isEmpty()) {
+            logger.severe(() -> "NO IMPLEMENTATION OF " + Handler.class.getName() + " FOUND. TERMINATING EXECUTION.");
+            throw new RuntimeException(exceptionMessageSupplier.get());
+        }
+        final Handler handler = optHandler.get();
+        final HttpResponse handlerResponse = handler.handle(requestMapper.map(request), logger);
+        return responseMapper.map(handlerResponse, request);
+    }
+
+    private static Optional<Handler> lookupHandler() {
+        return ServiceLoader.load(Handler.class).findFirst();
+    }
+    
+}

azure-provider/src/main/java/fr/axelop/agnosticserverlessfunctions/HttpRequestMapper.java

@@ -0,0 +1,51 @@
+package fr.axelop.agnosticserverlessfunctions;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import com.microsoft.azure.functions.HttpRequestMessage;
+
+class HttpRequestMapper {
+
+    public HttpRequest map(HttpRequestMessage<Optional<String>> azureRequest) {
+        final Map<String, List<String>> headers = Collections.unmodifiableMap(getHeaders(azureRequest));
+        return new HttpRequest() {
+
+            @Override
+            public Optional<String> getBody() {
+                return azureRequest.getBody();
+            }
+
+            @Override
+            public long getContentLength() {
+                return Long.parseLong(azureRequest.getHeaders().getOrDefault("Content-Length", "0"));
+            }
+
+            @Override
+            public Map<String, List<String>> getHeaders() {
+                return headers;
+            }
+
+            @Override
+            public String getMethod() {
+                return azureRequest.getHttpMethod().toString();
+            }
+
+        };
+    }
+
+    private Map<String, List<String>> getHeaders(HttpRequestMessage<Optional<String>> azureRequest) {
+        final Map<String, List<String>> headers = new HashMap<>(azureRequest.getHeaders().size());
+        for (Map.Entry<String, String> header : azureRequest.getHeaders().entrySet()) {
+            headers
+                    .computeIfAbsent(header.getKey(), k -> new ArrayList<>(1))
+                    .add(header.getValue());
+        }
+        return headers;
+    }
+
+}

azure-provider/src/main/java/fr/axelop/agnosticserverlessfunctions/HttpResponseMapper.java

@@ -0,0 +1,26 @@
+package fr.axelop.agnosticserverlessfunctions;
+
+import java.util.List;
+import java.util.Map;
+
+import com.microsoft.azure.functions.HttpRequestMessage;
+import com.microsoft.azure.functions.HttpResponseMessage;
+import com.microsoft.azure.functions.HttpStatus;
+
+class HttpResponseMapper {
+
+    HttpResponseMessage map(HttpResponse handlerResponse, HttpRequestMessage<?> azureRequest) {
+        final HttpStatus httpStatus = HttpStatus.valueOf(handlerResponse.getStatusCode());
+        final HttpResponseMessage.Builder builder = azureRequest.createResponseBuilder(httpStatus);
+        for (Map.Entry<String, List<String>> headerEntry : handlerResponse.getHeaders().entrySet()) {
+            for (String value : headerEntry.getValue()) {
+                builder.header(headerEntry.getKey(), value);
+            }
+        }
+        if (handlerResponse.getBody().isPresent()) {
+            builder.body(handlerResponse.getBody().get());
+        }   
+        return builder.build();
+    }
+    
+}

pom.xml

@@ -9,6 +9,7 @@
 
     <modules>
         <module>gcloud-provider</module>
+        <module>azure-provider</module>
     </modules>
 
     <properties>