Build layer during CI/CD workflows + some minor refactoring (aws-observability#989)

*Description of changes:*
- Running the lambda layer build script during PR to ensure that layer
builds successfully.
- During the main build, ensure that we can build the lambda layer and
also upload it to the staging bucket for further E2E testing. The E2E
test will be added in the subsequent PR.

*Testing:*
Triggered the main_build workflow in my fork:
https://github.com/srprash/aws-otel-java-instrumentation/actions/runs/12679487319/job/35339366348
- Observed that the layer zip file was successfully uploaded to the run:
https://github.com/srprash/aws-otel-java-instrumentation/actions/runs/12679487319/job/35339366348#step:5:22
- Upload to S3 fails since I don't have the right credentials in my
fork.


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

Author: srprash

.github/workflows/main-build.yml

@@ -226,8 +226,38 @@ jobs:
         with:
           arguments: contractTests -PlocalDocker=true
 
+  application-signals-lambda-layer-build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-java@v4
+        with:
+          java-version: 17
+          distribution: 'temurin'
+      - name: Build Application Signals Lambda Layer
+        working-directory: lambda-layer
+        run: |
+          ./build-layer.sh
+      - name: Upload layer zip to GitHub Actions
+        uses: actions/upload-artifact@v3
+        with:
+          name: aws-opentelemetry-java-layer.zip
+          path: lambda-layer/build/distributions/aws-opentelemetry-java-layer.zip
+      - name: Configure AWS Credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: arn:aws:iam::${{ secrets.APPLICATION_SIGNALS_E2E_TEST_ACCOUNT_ID }}:role/${{ secrets.APPLICATION_SIGNALS_E2E_TEST_ROLE_NAME }}
+          aws-region: us-east-1
+      - name: Upload layer zip to S3
+        working-directory: lambda-layer
+        run: |
+          aws s3 cp ./build/distributions/aws-opentelemetry-java-layer.zip s3://adot-main-build-staging-jar/adot-java-lambda-layer-${{ github.run_id }}.zip
+
+
   application-signals-e2e-test:
-    needs: [build]
+    needs: [build, application-signals-lambda-layer-build]
     uses: ./.github/workflows/application-signals-e2e-test.yml
     secrets: inherit
     with:
@@ -247,3 +277,4 @@ jobs:
       region: us-east-1
     secrets:
       roleArn: ${{ secrets.METRICS_ROLE_ARN }}
+

.github/workflows/pr-build.yml

@@ -156,3 +156,18 @@ jobs:
           arguments: build --stacktrace -PenableCoverage=true
       - uses: codecov/codecov-action@v3
 
+  build-lambda:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repo @ SHA - ${{ github.sha }}
+        uses: actions/checkout@v4
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          java-version: 17
+          distribution: temurin
+
+      - name: Build layer
+        working-directory: lambda-layer
+        run: ./build-layer.sh

lambda-layer/.gitignore

@@ -5,7 +5,7 @@
 build
 
 # Ignore Terraform state files
-.terraform
+.terraform/
 *.tfstate
 *.tfstate.backup
 *.lock.hcl

lambda-layer/build-layer.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -e
 
 SOURCEDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 
@@ -27,8 +28,6 @@ patch -p1 < "$SOURCEDIR"/../.github/patches/opentelemetry-java-instrumentation.p
 # This patch is for Lambda related context propagation
 patch -p1 < "$SOURCEDIR"/patches/opentelemetry-java-instrumentation.patch
 
-git add -A
-git commit -m "Create patch version"
 ./gradlew publishToMavenLocal
 popd
 rm -rf opentelemetry-java-instrumentation
@@ -46,8 +45,12 @@ popd
 echo "Info: Building ADOT Lambda Java SDK Layer Code"
 ./gradlew build -PotelVersion=${version}
 
-
 ## Copy ADOT Java Agent downloaded using Gradle task and bundle it with the Lambda handler script
 echo "Info: Creating the layer artifact"
-cp "$SOURCEDIR"/build/javaagent/aws-opentelemetry-agent*.jar ./opentelemetry-javaagent.jar
-zip -qr opentelemetry-javaagent-layer.zip opentelemetry-javaagent.jar otel-instrument
+mkdir -p "$SOURCEDIR"/build/distributions/
+cp "$SOURCEDIR"/build/javaagent/aws-opentelemetry-agent*.jar "$SOURCEDIR"/build/distributions/aws-opentelemetry-javaagent.jar
+zip -r ./build/distributions/aws-opentelemetry-java-layer.zip "$SOURCEDIR"/build/distributions/aws-opentelemetry-javaagent.jar otel-instrument
+
+## Cleanup
+# revert the patch applied since it is only needed while building the layer.
+git restore ../dependencyManagement/build.gradle.kts

lambda-layer/otel-instrument

@@ -6,7 +6,7 @@ export OTEL_PROPAGATORS="${OTEL_PROPAGATORS:-xray,tracecontext,b3,b3multi}"
 
 export OTEL_SERVICE_NAME=${OTEL_SERVICE_NAME:-${AWS_LAMBDA_FUNCTION_NAME}}
 
-export JAVA_TOOL_OPTIONS="-javaagent:/opt/opentelemetry-javaagent.jar ${JAVA_TOOL_OPTIONS}"
+export JAVA_TOOL_OPTIONS="-javaagent:/opt/aws-opentelemetry-javaagent.jar ${JAVA_TOOL_OPTIONS}"
 
 if [[ $OTEL_RESOURCE_ATTRIBUTES != *"service.name="* ]]; then
   export OTEL_RESOURCE_ATTRIBUTES="service.name=${AWS_LAMBDA_FUNCTION_NAME},${OTEL_RESOURCE_ATTRIBUTES}"