Merge pull request #38 from awslabs/servlet-improvements

Addressing issues #34, #35, and #37

Author: sapessi

aws-serverless-java-container-core/pom.xml

@@ -65,6 +65,15 @@
             <version>1.10.19</version>
             <scope>test</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpmime</artifactId>
+            <version>4.5.3</version>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
 
 </project>

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/LambdaContainerHandler.java

@@ -13,6 +13,7 @@
 package com.amazonaws.serverless.proxy.internal;
 
 
+import com.amazonaws.serverless.proxy.internal.model.ContainerConfig;
 import com.amazonaws.services.lambda.runtime.Context;
 
 import javax.ws.rs.core.SecurityContext;
@@ -36,6 +37,7 @@ public abstract class LambdaContainerHandler<RequestType, ResponseType, Containe
 
     public static final String SERVER_INFO = "aws-serverless-java-container";
 
+
     //-------------------------------------------------------------
     // Variables - Private
     //-------------------------------------------------------------
@@ -45,6 +47,15 @@ public abstract class LambdaContainerHandler<RequestType, ResponseType, Containe
     private SecurityContextWriter<RequestType> securityContextWriter;
     private ExceptionHandler<ResponseType> exceptionHandler;
 
+    protected Context lambdaContext;
+
+
+    //-------------------------------------------------------------
+    // Variables - Private - Static
+    //-------------------------------------------------------------
+
+    private static ContainerConfig config = ContainerConfig.defaultConfig();
+
 
     //-------------------------------------------------------------
     // Constructors
@@ -76,6 +87,19 @@ protected abstract void handleRequest(ContainerRequestType containerRequest, Con
     // Methods - Public
     //-------------------------------------------------------------
 
+    /**
+     * Configures the library to strip a base path from incoming requests before passing them on to the wrapped
+     * framework. This was added in response to issue #34 (https://github.com/awslabs/aws-serverless-java-container/issues/34).
+     * When creating a base path mapping for custom domain names in API Gateway we want to be able to strip the base path
+     * from the request - the underlying service may not recognize this path.
+     * @param basePath The base path to be stripped from the request
+     */
+    public void stripBasePath(String basePath) {
+        config.setStripBasePath(true);
+        config.setServiceBasePath(basePath);
+    }
+
+
     /**
      * Proxies requests to the underlying container given the incoming Lambda request. This method returns a populated
      * return object for the Lambda function.
@@ -85,11 +109,12 @@ protected abstract void handleRequest(ContainerRequestType containerRequest, Con
      * @return A valid response type
      */
     public ResponseType proxy(RequestType request, Context context) {
+        lambdaContext = context;
         try {
             SecurityContext securityContext = securityContextWriter.writeSecurityContext(request, context);
             CountDownLatch latch = new CountDownLatch(1);
             ContainerResponseType containerResponse = getContainerResponse(latch);
-            ContainerRequestType containerRequest = requestReader.readRequest(request, securityContext, context);
+            ContainerRequestType containerRequest = requestReader.readRequest(request, securityContext, context, config);
 
             handleRequest(containerRequest, containerResponse, context);
 
@@ -98,13 +123,22 @@ public ResponseType proxy(RequestType request, Context context) {
             return responseWriter.writeResponse(containerResponse, context);
         } catch (Exception e) {
             context.getLogger().log("Error while handling request: " + e.getMessage());
-
-            /*for (StackTraceElement el : e.getStackTrace()) {
-                context.getLogger().log(el.toString());
-            }*/
             e.printStackTrace();
 
             return exceptionHandler.handle(e);
         }
     }
+
+
+    //-------------------------------------------------------------
+    // Methods - Getter/Setter
+    //-------------------------------------------------------------
+
+    /**
+     * Returns the current container configuration object.
+     * @return
+     */
+    public static ContainerConfig getContainerConfig() {
+        return config;
+    }
 }

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/RequestReader.java

@@ -14,6 +14,7 @@
 
 
 import com.amazonaws.serverless.exceptions.InvalidRequestEventException;
+import com.amazonaws.serverless.proxy.internal.model.ContainerConfig;
 import com.amazonaws.services.lambda.runtime.Context;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -67,9 +68,36 @@ public abstract class RequestReader<RequestType, ContainerRequestType> {
      * @return A valid request object for the underlying container
      * @throws InvalidRequestEventException This exception is thrown if anything goes wrong during the creation of the request object
      */
-    protected abstract ContainerRequestType readRequest(RequestType request, SecurityContext securityContext, Context lambdaContext)
+    protected abstract ContainerRequestType readRequest(RequestType request, SecurityContext securityContext, Context lambdaContext, ContainerConfig config)
             throws InvalidRequestEventException;
 
 
     protected abstract Class<? extends RequestType> getRequestClass();
+
+
+    //-------------------------------------------------------------
+    // Methods - Protected
+    //-------------------------------------------------------------
+
+    /**
+     * Strips the base path from the request path if the container configuration object requires it
+     * @param requestPath The incoming request path
+     * @param config The container configuration object
+     * @return The final request path
+     */
+    protected String stripBasePath(String requestPath, ContainerConfig config) {
+        if (!config.isStripBasePath()) {
+            return requestPath;
+        }
+
+        if (requestPath.startsWith(config.getServiceBasePath())) {
+            String newRequestPath = requestPath.replaceFirst(config.getServiceBasePath(), "");
+            if (!newRequestPath.startsWith("/")) {
+                newRequestPath = "/" + newRequestPath;
+            }
+            return newRequestPath;
+        }
+
+        return requestPath;
+    }
 }

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/model/ContainerConfig.java

@@ -0,0 +1,56 @@
+package com.amazonaws.serverless.proxy.internal.model;
+
+
+/**
+ * Configuration paramters used by the <code>RequestReader</code> and <code>ResponseWriter</code> objects.
+ */
+public class ContainerConfig {
+
+    public static ContainerConfig defaultConfig() {
+        ContainerConfig configuration = new ContainerConfig();
+        configuration.setStripBasePath(false);
+
+        return configuration;
+    }
+
+    //-------------------------------------------------------------
+    // Variables - Private
+    //-------------------------------------------------------------
+
+    private String serviceBasePath;
+    private boolean stripBasePath;
+
+
+    //-------------------------------------------------------------
+    // Methods - Getter/Setter
+    //-------------------------------------------------------------
+
+    public String getServiceBasePath() {
+        return serviceBasePath;
+    }
+
+
+    public void setServiceBasePath(String serviceBasePath) {
+        // clean up base path before setting it, we want a "/" at the beginning but not at the end.
+        String finalBasePath = serviceBasePath;
+        if (!finalBasePath.startsWith("/")) {
+            finalBasePath = "/" + serviceBasePath;
+        }
+        if (finalBasePath.endsWith("/")) {
+            finalBasePath = finalBasePath.substring(0, finalBasePath.length() - 1);
+        }
+        this.serviceBasePath = finalBasePath;
+    }
+
+
+    public boolean isStripBasePath() {
+        return stripBasePath;
+    }
+
+
+    public void setStripBasePath(boolean stripBasePath) {
+        this.stripBasePath = stripBasePath;
+    }
+
+
+}

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsHttpServletRequest.java

@@ -23,7 +23,13 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
-import java.util.*;
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 
@@ -56,6 +62,9 @@ public abstract class AwsHttpServletRequest implements HttpServletRequest {
 
     private Context lambdaContext;
     private Map<String, Object> attributes;
+    private ServletContext servletContext;
+
+    protected DispatcherType dispatcherType;
 
 
     //-------------------------------------------------------------
@@ -72,6 +81,7 @@ public abstract class AwsHttpServletRequest implements HttpServletRequest {
         attributes = new HashMap<>();
     }
 
+
     //-------------------------------------------------------------
     // Implementation - HttpServletRequest
     //-------------------------------------------------------------
@@ -119,6 +129,7 @@ public boolean isRequestedSessionIdFromURL() {
 
 
     @Override
+    @Deprecated
     public boolean isRequestedSessionIdFromUrl() {
         return false;
     }
@@ -185,7 +196,7 @@ public int getLocalPort() {
 
     @Override
     public ServletContext getServletContext() {
-        return AwsServletContext.getInstance(lambdaContext);
+        return servletContext;
     }
 
 
@@ -213,6 +224,19 @@ public DispatcherType getDispatcherType() {
     }
 
 
+    //-------------------------------------------------------------
+    // Methods - Getter/Setter
+    //-------------------------------------------------------------
+
+    public void setDispatcherType(DispatcherType type) {
+        dispatcherType = type;
+    }
+
+    public void setServletContext(ServletContext context) {
+        servletContext = context;
+    }
+
+
     //-------------------------------------------------------------
     // Methods - Protected
     //-------------------------------------------------------------
@@ -223,7 +247,6 @@ public DispatcherType getDispatcherType() {
      * @return An array of Cookie objects from the header
      */
     protected Cookie[] parseCookieHeaderValue(String headerValue) {
-
         List<Map.Entry<String, String>> parsedHeaders = this.parseHeaderValue(headerValue);
 
         return parsedHeaders.stream()
@@ -232,6 +255,7 @@ protected Cookie[] parseCookieHeaderValue(String headerValue) {
                             .toArray(Cookie[]::new);
     }
 
+
     /**
      * Given a map of key/values query string parameters from API Gateway, creates a query string as it would have
      * been in the original url.

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsHttpServletResponse.java

@@ -188,6 +188,7 @@ public void setStatus(int i) {
 
 
     @Override
+    @Deprecated
     public void setStatus(int i, String s) {
         statusCode = i;
         statusMessage = s;