feat(v2): Add GraalVM reachability metadata for core utilities

GraalVM.md

@@ -0,0 +1,188 @@
+# GraalVM Compatibility for AWS Lambda Powertools Java
+
+## Table of Contents
+- [Overview](#overview)
+- [Prerequisites](#prerequisites)
+- [General Implementation Steps](#general-implementation-steps)
+- [Known Issues and Solutions](#known-issues-and-solutions)
+- [Reference Implementation](#reference-implementation)
+- [Module-Specific Implementation](#module-specific-implementation)
+   - [1. Powertools Common](#1-powertools-common)
+   - [2. Powertools Logging](#2-powertools-logging)
+      - [2.1 Powertools Logging (log4j)](#21-powertools-logging-log4j)
+      - [2.2 Powertools Logging (logback)](#22-powertools-logging-logback)
+   - [3. Powertools Metrics](#3-powertools-metrics)
+
+## Overview
+This documentation provides guidance for adding GraalVM support for AWS Lambda Powertools Java modules and using the modules in Lambda functions.
+
+## Prerequisites
+- GraalVM 21+ installation
+- Maven 3.x
+
+## General Implementation Steps
+GraalVM native image compilation requires complete knowledge of an application's dynamic features at build time. The GraalVM reachability metadata (GRM) JSON files are essential because Java applications often use features that are determined at runtime, such as reflection, dynamic proxy classes, resource loading, and JNI (Java Native Interface). The metadata files tell GraalVM which classes need reflection access, which resources need to be included in the native image, and which proxy classes need to be generated.
+
+In order to generate the metadata reachability files for Powertools for Lambda, follow these general steps.
+
+1. **Add Maven Profiles**
+    - Add profile for generating GraalVM reachability metadata files. You can find an example of this in profile `generate-graalvm-files` of this [pom.xml](powertools-common/pom.xml). 
+    - Add another profile for running the tests in the native image. You can find and example of this in profile `graalvm-native` of this [pom.xml](powertools-common/pom.xml).
+
+2. **Generate Reachability Metadata**
+    - Set the `JAVA_HOME` environment variable to use GraalVM
+    - Run tests with `-Pgenerate-graalvm-files` profile. You can find module specific commands in the [Module-Specific Implementation](#module-specific-implementation) section
+    - Some tests may need to be skipped depending on the module
+
+3. **Validate Native Image Tests**
+    - Set the `JAVA_HOME` environment variable to use GraalVM
+    - Run tests with `-Pgraalvm-native` profile. This will build a GraalVM native image and run the JUnit tests. You can find module specific commands in the [Module-Specific Implementation](#module-specific-implementation) section
+    - Verify test execution in native mode
+
+4. **Clean Up Metadata**
+    -  GraalVM metadata reachability files generated in Step 2 contains references to the test scoped dependencies as well.
+    - Remove the references in generated metadata files for the following (and any other references to test scoped resources and classes):
+        - JUnit
+        - Mockito
+        - ByteBuddy
+
+## Known Issues and Solutions
+
+1. **Mockito Compatibility**
+   - Powertools uses Mockito 5.x which uses “inline mock maker” as the default. This mock maker does not play well with GraalVM. Mockito [recommends](https://github.com/mockito/mockito/releases/tag/v5.0.0) using subclass mock maker with GraalVM.
+   - However, subclass mock maker does not support testing static methods. Some test cases in Powertools uses inline mock maker to mock static methods. These tests have to be skipped while generating the GraalVM reachability metadata files. 
+   - This obviously affects the coverage and possibility of missing a required entry in GRM files. At this point we are relying on community to report any missing entries and will update the GRM based on the reports.
+   - This issue remains open until ability of test static methods in Mockito 5.x/inline mock maker is available.
+
+2. **Log4j Compatibility**
+   - Version 2.22.1 fails with this error
+```
+java.lang.InternalError: com.oracle.svm.core.jdk.UnsupportedFeatureError: Defining hidden classes at runtime is not supported.
+```
+   - This has been [fixed](https://github.com/apache/logging-log4j2/discussions/2364#discussioncomment-8950077) in Log4j 2.24.0. PT has been updated to use this version of Log4j 
+
+
+## Reference Implementation
+Working example is available in the [examples](examples/powertools-examples-core-utilities/sam-graalvm). 
+
+## Module-Specific Implementation
+Due to the Mockito issues described in the [Known Issues and Solutions](#known-issues-and-solutions) section, some tests needs to be skipped when generating the GRM files. This section shows the commands that need to be used for the modules.   
+
+### 1. Powertools Common
+
+Generate metadata files
+```shell
+
+mvn \
+-Dtest=\
+\!UserAgentConfiguratorTest#testGetVersionFromProperties_InvalidFile,\
+\!UserAgentConfiguratorTest#testGetVersion,\
+\!UserAgentConfiguratorTest#testGetUserAgent_SetAWSExecutionEnv,\
+\!LambdaHandlerProcessorTest#serviceName_Undefined,\
+\!LambdaHandlerProcessorTest#serviceName,\
+\!LambdaHandlerProcessorTest#isSamLocal,\
+\!LambdaHandlerProcessorTest#getXrayTraceId_present,\
+\!LambdaHandlerProcessorTest#getXrayTraceId_notPresent \
+ -Pgenerate-graalvm-files clean test
+```
+
+Run native tests
+```shell
+
+mvn \
+-Dtest=\
+\!UserAgentConfiguratorTest#testGetVersionFromProperties_InvalidFile,\
+\!UserAgentConfiguratorTest#testGetVersion,\
+\!UserAgentConfiguratorTest#testGetUserAgent_SetAWSExecutionEnv,\
+\!LambdaHandlerProcessorTest#serviceName_Undefined,\
+\!LambdaHandlerProcessorTest#serviceName,\
+\!LambdaHandlerProcessorTest#isSamLocal,\
+\!LambdaHandlerProcessorTest#getXrayTraceId_present,\
+\!LambdaHandlerProcessorTest#getXrayTraceId_notPresent \
+ -Pgraalvm-native clean test
+
+```
+
+### 2. Powertools Logging
+
+Generate metadata files
+```shell
+
+mvn  -Dtest=\!LambdaLoggingAspectTest#shouldLogxRayTraceIdEnvVarSet,\
+\!LambdaLoggingAspectTest#shouldLogxRayTraceIdSystemPropertySet \
+ -Pgenerate-graalvm-files clean test
+
+```
+
+Run native tests
+```shell
+
+mvn  -Dtest=\!LambdaLoggingAspectTest#shouldLogxRayTraceIdEnvVarSet,\
+\!LambdaLoggingAspectTest#shouldLogxRayTraceIdSystemPropertySet \
+ -Pgraalvm-native clean test
+
+```
+#### 2.1 Powertools Logging (log4j)
+
+Generate metadata files
+```shell
+
+mvn  -Dtest=\!PowertoolsResolverTest#shouldResolveRegion \
+ -Pgenerate-graalvm-files clean test
+
+```
+
+Run native tests
+```shell
+
+mvn  -Dtest=\!PowertoolsResolverTest#shouldResolveRegion \
+-Pgraalvm-native clean test
+
+```
+
+#### 2.2 Powertools Logging (logback)
+
+Generate metadata files
+```shell
+
+mvn -Dtest=\!MetricsLoggerTest#shouldLogxRayTraceIdEnvVarSet,\
+\!MetricsLoggerTest#shouldLogxRayTraceIdSystemPropertySet \
+ -Pgenerate-graalvm-files clean test
+
+```
+
+Run native tests
+```shell
+
+mvn -Dtest=\!MetricsLoggerTest#shouldLogxRayTraceIdEnvVarSet,\
+\!MetricsLoggerTest#shouldLogxRayTraceIdSystemPropertySet \
+ -Pgraalvm-native clean test
+```
+
+### 3. Powertools Metrics
+* All tests need to mock static methods. 
+* Comment out the references to `mockStatic` in the JUnits and set the env variables explicitly
+* Also pass the system property via mvn build cli
+
+Generate metadata files
+```shell
+
+export AWS_EMF_ENVIRONMENT="Lambda"
+export _X_AMZN_TRACE_ID="Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=1"
+export POWERTOOLS_METRICS_NAMESPACE="GlobalName"
+
+mvn -Dcom.amazonaws.xray.traceHeader="Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=1" \
+ -Pgenerate-graalvm-files clean test
+```
+
+Run native tests
+```shell
+
+export AWS_EMF_ENVIRONMENT="Lambda"
+export _X_AMZN_TRACE_ID="Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=1"
+export POWERTOOLS_METRICS_NAMESPACE="GlobalName"
+
+mvn -Dcom.amazonaws.xray.traceHeader="Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=1" \
+ -Pgraalvm-native clean test
+
+```

docs/FAQs.md

@@ -142,4 +142,113 @@ The following example shows how to use the Lambda Powertools Parameters module w
     }
     ```
 The `aws-crt-client` was considered for adoption as the default HTTP client in Lambda Powertools for Java as mentioned in [Move SDK http client to CRT](https://github.com/aws-powertools/powertools-lambda-java/issues/1092), 
-but due to the impact on the developer experience it was decided to stick with the `url-connection-client`. 
+but due to the impact on the developer experience it was decided to stick with the `url-connection-client`.
+
+## How can I use Powertools for AWS Lambda (Java) with GraalVM?
+
+Powertools core utilities, i.e. [logging](./core/logging.md), [metrics](./core/metrics.md) and [tracing](./core/tracing.md), include the [GraalVM Reachability Metadata (GRM)](https://www.graalvm.org/latest/reference-manual/native-image/metadata/) in the `META-INF` directories of the respective JARs. You can find a working example of Serverless Application Model (SAM) based application in the [examples](../examples/powertools-examples-core-utilities/sam-graalvm/README.md) directory.
+
+These are typical steps you need to follow in a maven based Java project
+
+### Set the environment to use GraalVM
+
+```shell
+export JAVA_HOME=<path to GraalVM>
+```
+
+### Use log4j > 2.24.0
+Log4j version `2.24.0` adds [support for GraalVM](https://github.com/apache/logging-log4j2/issues/1539#issuecomment-2106766878). Depending on your project's dependency hierarchy, older version of log4j might be included in the final dependency graph. Make sure version `>2.24.0` of these dependencies are used by your maven project:
+
+```xml
+<dependencies>
+    <dependency>
+        <groupId>org.apache.logging.log4j</groupId>
+        <artifactId>log4j-api</artifactId>
+        <version>${log4j.version}</version>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.logging.log4j</groupId>
+        <artifactId>log4j-core</artifactId>
+        <version>${log4j.version}</version>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.logging.log4j</groupId>
+        <artifactId>log4j-slf4j2-impl</artifactId>
+        <version>${log4j.version}</version>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.logging.log4j</groupId>
+        <artifactId>log4j-layout-template-json</artifactId>
+        <version>${log4j.version}</version>
+    </dependency>
+</dependencies>
+
+```
+
+### Add the AWS Lambda Java Runtime Interface Client dependency
+
+Runtime Interface Client allow your function to receive invocation events from Lambda, send the response back to Lambda, and report errors to the Lambda service. Add the below dependency to your maven project:
+
+```xml
+<dependency>
+    <groupId>com.amazonaws</groupId>
+    <artifactId>aws-lambda-java-runtime-interface-client</artifactId>
+    <version>2.1.1</version>
+</dependency>
+```
+
+Also include the AWS Lambda GRM files by copying the `com.amazonaws`[directory](../examples/powertools-examples-core-utilities/sam-graalvm/src/main/resources/META-INF/native-image/) in your project's `META-INF/native-image` directory
+
+### Build the native image
+
+1. Use the `native-maven-plugin` to build the native image. You can do this by adding the plugin to your `pom.xml` and creating a build profile called `native-image` that can build the native image of your Lambda function:
+
+```xml
+<profiles>
+    <profile>
+        <id>native-image</id>
+        <build>
+            <plugins>
+                <plugin>
+                    <groupId>org.graalvm.buildtools</groupId>
+                    <artifactId>native-maven-plugin</artifactId>
+                    <version>0.10.1</version>
+                    <extensions>true</extensions>
+                    <executions>
+                        <execution>
+                            <id>build-native</id>
+                            <goals>
+                                <goal>build</goal>
+                            </goals>
+                            <phase>package</phase>
+                        </execution>
+                    </executions>
+                    <configuration>
+                        <imageName>your-project-name</imageName>
+                        <mainClass>com.amazonaws.services.lambda.runtime.api.client.AWSLambda</mainClass>
+                        <buildArgs>
+                            <!-- required for AWS Lambda Runtime Interface Client -->
+                            <arg>--enable-url-protocols=http</arg>
+                            <arg>--add-opens java.base/java.util=ALL-UNNAMED</arg>
+                        </buildArgs>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </build>
+    </profile>
+</profiles>
+```
+
+2. Create a docker image using a Dockerfile like [this](../examples/powertools-examples-core-utilities/sam-graalvm/Dockerfile) to create an x86 based build image.
+
+```shell
+docker build --platform linux/amd64 . -t your-org/your-app-graalvm-builder
+```
+
+3. Create the native image of you Lambda function using the docker command below. 
+
+```shell
+docker run --platform linux/amd64 -it -v `pwd`:`pwd` -w `pwd` -v ~/.m2:/root/.m2 your-org/your-app-graalvm-builder mvn clean -Pnative-image package
+
+```
+The native image is created in the target directory.

examples/powertools-examples-core-utilities/sam-graalvm/Dockerfile

@@ -0,0 +1,14 @@
+#Use the official AWS SAM base image for Java 21
+FROM public.ecr.aws/sam/build-java21:latest
+
+#Install GraalVM dependencies
+RUN curl -4 -L curl https://download.oracle.com/graalvm/21/latest/graalvm-jdk-21_linux-x64_bin.tar.gz | tar -xvz
+RUN mv graalvm-jdk-21.* /usr/lib/graalvm
+
+#Make native image and mvn available on CLI
+RUN ln -s /usr/lib/graalvm/bin/native-image /usr/bin/native-image
+RUN ln -s /usr/lib/maven/bin/mvn /usr/bin/mvn
+
+#Set GraalVM as default
+ENV JAVA_HOME=/usr/lib/graalvm
+ENV PATH=/usr/lib/graalvm/bin:$PATH

examples/powertools-examples-core-utilities/sam-graalvm/Makefile

@@ -0,0 +1,6 @@
+build-HelloWorldFunction:
+	mvn clean package -P native-image
+	chmod +x target/hello-world
+	cp target/hello-world $(ARTIFACTS_DIR) # (ARTIFACTS_DIR --> https://github.com/aws/aws-lambda-builders/blob/develop/aws_lambda_builders/workflows/custom_make/DESIGN.md#implementation)
+	chmod +x src/main/config/bootstrap
+	cp src/main/config/bootstrap $(ARTIFACTS_DIR)

examples/powertools-examples-core-utilities/sam-graalvm/README.md

@@ -0,0 +1,56 @@
+#  Powertools for AWS Lambda (Java) - Core Utilities Example with SAM on GraalVM
+
+This project demonstrates the Lambda for Powertools Java module deployed using [Serverless Application Model](https://aws.amazon.com/serverless/sam/) running as a GraalVM native image.
+
+For general information on the deployed example itself, you can refer to the parent [README](../README.md)
+
+## Configuration
+ - SAM uses [template.yaml](template.yaml) to define the application's AWS resources.
+This file defines the Lambda function to be deployed as well as API Gateway for it.
+
+ - Set the environment to use GraalVM
+
+```shell 
+export JAVA_HOME=<path to GraalVM>
+```
+
+## Build the sample application
+
+- Build the Docker image that will be used as the environment for SAM build:
+```shell
+docker build --platform linux/amd64 . -t powertools-examples-core-sam-graalvm
+```
+
+- Build the SAM project using the docker image
+```shell
+sam build --use-container --build-image powertools-examples-core-sam-graalvm
+
+```
+#### [Optional] Building with -SNAPSHOT versions of PowerTools
+- If you are testing the example with a -SNAPSHOT version of PowerTools, the maven build inside the docker image will fail. This is because the -SNAPSHOT version of the PowerTools library that you are working on is still not available in maven central/snapshot repository.
+To get around this, follow these steps: 
+  - Create the native image using the `docker` command below on your development machine. The native image is created in the `target` directory. 
+    - ```docker run --platform linux/amd64  -it -v `pwd`:`pwd` -w `pwd` -v ~/.m2:/root/.m2 powertools-examples-core-sam-graalvm mvn clean -Pnative-image package -DskipTests```
+  - Edit the [`Makefile`](Makefile) remove this line
+    - ```mvn clean package -P native-image```
+  - Build the SAM project using the docker image
+    - ```sam build --use-container --build-image powertools-examples-core-sam-graalvm```
+
+## Deploy the sample application
+- SAM deploy
+
+       sam deploy
+
+To deploy the example, check out the instructions for getting
+started with SAM in [the examples directory](../../README.md)
+
+## Additional notes
+
+You can watch the trace information or log information using the SAM CLI:
+```bash
+# Tail the logs
+sam logs --tail $MY_STACK
+
+# Tail the traces
+sam traces --tail
+```