@@ -9,12 +9,50 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    
+    services:
+      localstack:
+        image: localstack/localstack:latest
+        ports:
+          - 4566:4566
+        env:
+          SERVICES: sqs,sns,kms,iam
+          DEBUG: 1
+          DOCKER_HOST: unix:///var/run/docker.sock
+        options: >-
+          --health-cmd "curl -f http://localhost:4566/_localstack/health || exit 1"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 30
+          --health-start-period 30s
+    
     steps:
     - uses: actions/checkout@v3
     - name: Setup .NET
       uses: actions/setup-dotnet@v3
       with:
         dotnet-version: 9.0.x
+    
+    - name: Verify LocalStack is Ready
+      run: |
+        echo "Waiting for LocalStack to be fully ready..."
+        max_attempts=30
+        attempt=0
+        while [ $attempt -lt $max_attempts ]; do
+          if curl -f http://localhost:4566/_localstack/health 2>/dev/null; then
+            echo "LocalStack is ready!"
+            curl -s http://localhost:4566/_localstack/health | jq '.'
+            break
+          fi
+          attempt=$((attempt + 1))
+          echo "Attempt $attempt/$max_attempts - LocalStack not ready yet, waiting..."
+          sleep 3
+        done
+        if [ $attempt -eq $max_attempts ]; then
+          echo "ERROR: LocalStack did not become ready in time"
+          exit 1
+        fi
+    
     - name: Restore dependencies
       run: dotnet restore
     - name: Build
@@ -24,32 +62,6 @@ jobs:
     - name: Run Unit Tests
       run: dotnet test --no-build --verbosity normal --filter "Category=Unit"
 
-    # Start LocalStack container for integration tests
-    - name: Start LocalStack Container
-      run: |
-        docker run -d \
-          --name localstack \
-          -p 4566:4566 \
-          -e SERVICES=sqs,sns,kms,iam \
-          -e DEBUG=1 \
-          -e DOCKER_HOST=unix:///var/run/docker.sock \
-          localstack/localstack:latest
-        
-        # Wait for LocalStack to be ready (max 60 seconds)
-        echo "Waiting for LocalStack to be ready..."
-        timeout 60 bash -c 'until docker exec localstack curl -s http://localhost:4566/_localstack/health | grep -q "\"sqs\": \"available\""; do sleep 2; done' || echo "LocalStack startup timeout"
-        
-        # Display LocalStack health status
-        docker exec localstack curl -s http://localhost:4566/_localstack/health
-    
-    # Configure AWS SDK to use LocalStack endpoints
-    - name: Configure AWS SDK for LocalStack
-      run: |
-        echo "AWS_ACCESS_KEY_ID=test" >> $GITHUB_ENV
-        echo "AWS_SECRET_ACCESS_KEY=test" >> $GITHUB_ENV
-        echo "AWS_DEFAULT_REGION=us-east-1" >> $GITHUB_ENV
-        echo "AWS_ENDPOINT_URL=http://localhost:4566" >> $GITHUB_ENV
-    
     # Run integration tests against LocalStack
     - name: Run Integration Tests with LocalStack
       run: dotnet test --no-build --verbosity normal --filter "Category=Integration&Category=RequiresLocalStack"
@@ -58,13 +70,6 @@ jobs:
         AWS_SECRET_ACCESS_KEY: test
         AWS_DEFAULT_REGION: us-east-1
         AWS_ENDPOINT_URL: http://localhost:4566
-    
-    # Clean up LocalStack container
-    - name: Stop LocalStack Container
-      if: always()
-      run: |
-        docker stop localstack || true
-        docker rm localstack || true
 
   run-Lint:
       runs-on: ubuntu-latest
 
@@ -12,6 +12,23 @@ permissions:
 jobs:
   Build-Test-Publish:
     runs-on: ubuntu-latest
+    
+    services:
+      localstack:
+        image: localstack/localstack:latest
+        ports:
+          - 4566:4566
+        env:
+          SERVICES: sqs,sns,kms,iam
+          DEBUG: 1
+          DOCKER_HOST: unix:///var/run/docker.sock
+        options: >-
+          --health-cmd "curl -f http://localhost:4566/_localstack/health || exit 1"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 30
+          --health-start-period 30s
+    
     env:
       working-directory: ${{ github.workspace }}
       github-token: '${{ secrets.GH_Packages }}'
@@ -49,42 +66,62 @@ jobs:
         with:
           dotnet-version: 9.0.x
 
-      - name: Step-06 Restore dependencies
+      - name: Step-06 Verify LocalStack is Ready
+        run: |
+          echo "Waiting for LocalStack to be fully ready..."
+          max_attempts=30
+          attempt=0
+          while [ $attempt -lt $max_attempts ]; do
+            if curl -f http://localhost:4566/_localstack/health 2>/dev/null; then
+              echo "LocalStack is ready!"
+              curl -s http://localhost:4566/_localstack/health | jq '.'
+              break
+            fi
+            attempt=$((attempt + 1))
+            echo "Attempt $attempt/$max_attempts - LocalStack not ready yet, waiting..."
+            sleep 3
+          done
+          if [ $attempt -eq $max_attempts ]; then
+            echo "ERROR: LocalStack did not become ready in time"
+            exit 1
+          fi
+
+      - name: Step-07 Restore dependencies
         run: dotnet restore
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-07 Build Version (Pre-release)
+      - name: Step-08 Build Version (Pre-release)
         if: ${{ env.is-release != 'true' }}
         run: dotnet build --configuration Release --no-restore -p:PackageVersion=${{ steps.gitversion.outputs.NuGetVersion }}
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-07 Build Version (Release)
+      - name: Step-08 Build Version (Release)
         if: ${{ env.is-release == 'true' }}
         run: dotnet build --configuration Release --no-restore -p:PackageVersion=${{ steps.gitversion.outputs.MajorMinorPatch }}
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-08 Test Solution
+      - name: Step-09 Test Solution
         run: dotnet test --configuration Release --no-build --no-restore --verbosity normal
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-09 Create NuGet Package (Pre-release)
+      - name: Step-10 Create NuGet Package (Pre-release)
         if: ${{ env.is-release != 'true' }}
         run: dotnet pack --configuration Release --no-build --output ./packages -p:PackageVersion=${{ steps.gitversion.outputs.NuGetVersion }}
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-09 Create NuGet Package (Release)
+      - name: Step-10 Create NuGet Package (Release)
         if: ${{ env.is-release == 'true' }}
         run: dotnet pack --configuration Release --no-build --output ./packages -p:PackageVersion=${{ steps.gitversion.outputs.MajorMinorPatch }}
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-10 Publish to Github Packages
+      - name: Step-11 Publish to Github Packages
         if: ${{ env.is-release == 'true' }}
         run: |
           dotnet tool install gpr --global
           find ./packages -name "*.nupkg" -print -exec gpr push -k ${{ env.github-token }} {} \;
         working-directory: '${{ env.working-directory }}'
 
-      - name: Step-11 Publish to NuGet.org
+      - name: Step-12 Publish to NuGet.org
         if: ${{ 'false' && env.is-release == 'true' && env.nuget-token != '' }}
         run: |
           find ./packages -name "*.nupkg" -print -exec dotnet nuget push {} --skip-duplicate --api-key ${{ env.nuget-token }} --source https://api.nuget.org/v3/index.json \;
 
@@ -158,8 +158,9 @@ Assuming our root cause analysis is correct:
 1. **Enhance External Instance Detection**: Improve `IsExternalLocalStackAvailableAsync` method
    - Increase timeout from 3 seconds to 10 seconds for CI environments
    - Add retry logic (3 attempts with 2-second delays)
-   - Check not just for HTTP 200 but also parse JSON to verify services are "available"
-   - Log detection results for diagnostics
+   - **Lenient Detection**: Accept HTTP 200 from health endpoint even if services aren't fully initialized
+   - Defer full service readiness validation to `WaitForServicesAsync`
+   - Log detection results for diagnostics with service status details when available
 
 2. **Improve Wait Strategy**: Modify `StartAsync` to add initial delay after container start
    - Add 5-second delay after `_container.StartAsync()` completes
 
@@ -629,11 +629,20 @@ public async Task All_Configured_Resources_Should_Exist_After_Bootstrapping()
 
 The test infrastructure includes specific optimizations for GitHub Actions CI environments:
 
+**LocalStack Service Container Integration:**
+- **Pre-Started Container** - Release-CI workflow includes LocalStack as a service container
+- **Port Mapping** - LocalStack exposed on port 4566 for test access
+- **Service Configuration** - Configured with SQS, SNS, KMS, and IAM services
+- **Health Checks** - Container health validated before test execution begins
+- **Automatic Lifecycle** - GitHub Actions manages container startup and cleanup
+- **Resource Efficiency** - Single shared container across all test jobs
+
 **LocalStack Timeout Handling:**
 - **Environment Detection** - Automatically detects GitHub Actions via `GITHUB_ACTIONS` environment variable
 - **Extended Timeouts** - Uses 90-second health check timeout in CI (vs 30 seconds locally) to accommodate slower container initialization
-- **Enhanced Retry Logic** - Increases retry attempts (20 vs 15) and delays (3 seconds vs 2 seconds) for CI environments
-- **External Instance Detection** - 10-second timeout (vs 3 seconds locally) to reliably detect pre-started LocalStack service containers
+- **Enhanced Retry Logic** - Increases retry attempts (30 vs 15) and delays (3 seconds vs 2 seconds) for CI environments
+- **External Instance Detection** - 10-second timeout (vs 3 seconds locally) with 3 retry attempts to reliably detect pre-started LocalStack service containers
+- **Lenient Detection** - Accepts HTTP 200 from health endpoint even if services aren't fully initialized, deferring full readiness validation to main wait loop
 
 **Container Sharing:**
 - **xUnit Collection Fixtures** - `AwsIntegrationTestCollection` enforces shared `LocalStackTestFixture` across all test classes
@@ -645,6 +654,35 @@ The test infrastructure includes specific optimizations for GitHub Actions CI en
 - `LocalStackConfiguration.IsCI` - Property that detects GitHub Actions environment
 - `LocalStackManager.WaitForServicesAsync()` - Adaptive retry logic based on environment detection
 
+**GitHub Actions Workflow Configuration:**
+
+The Release-CI workflow includes LocalStack as a service container:
+
+```yaml
+services:
+  localstack:
+    image: localstack/localstack:latest
+    ports:
+      - 4566:4566
+    env:
+      SERVICES: sqs,sns,kms,iam
+      DEBUG: 1
+      DOCKER_HOST: unix:///var/run/docker.sock
+    options: >-
+      --health-cmd "curl -f http://localhost:4566/_localstack/health || exit 1"
+      --health-interval 10s
+      --health-timeout 5s
+      --health-retries 30
+      --health-start-period 30s
+```
+
+**Service Container Benefits:**
+- Container starts before test job begins
+- Health checks ensure services are ready before tests run
+- Automatic cleanup after job completion
+- No manual container management required in test code
+- Consistent environment across all CI runs
+
 ### Reporting and Analysis
 - **Comprehensive Reports** - Detailed test results with metrics and analysis
 - **Performance Trends** - Historical performance tracking and regression detection
@@ -664,6 +702,29 @@ The `AwsResourceManager` provides comprehensive automated resource lifecycle man
 - **Test Isolation** - Unique naming prevents conflicts in parallel test execution
 
 ### LocalStack Manager (Implemented)
+The `LocalStackManager` provides comprehensive container lifecycle management for AWS service emulation with enhanced features:
+
+- **Smart Container Detection** - Automatically detects and reuses existing LocalStack instances (e.g., in CI/CD environments) to avoid redundant container creation
+- **Adaptive Timeout Configuration** - Automatically adjusts health check timeouts based on environment (90 seconds for CI, 30 seconds for local development)
+- **Enhanced External Instance Detection** - Accepts HTTP 200 responses from LocalStack health endpoint even if services aren't fully initialized, deferring full service readiness validation to the main wait loop
+- **Retry Logic** - Configurable retry attempts with delays for reliable external instance detection (3 attempts with 2-second delays)
+- **Port Management** - Automatic port conflict detection and resolution
+- **Service Validation** - Comprehensive AWS service emulation validation (SQS, SNS, KMS, IAM)
+- **Diagnostic Logging** - Detailed logging for troubleshooting container startup and service initialization issues
+
+**External Instance Detection Behavior:**
+- Checks for existing LocalStack instances before starting new containers
+- Uses lenient detection: accepts HTTP 200 from health endpoint regardless of service status
+- Allows services to continue initializing after detection succeeds
+- Full service readiness validation occurs in `WaitForServicesAsync` with appropriate timeouts
+- Prevents port conflicts and reduces CI execution time by reusing pre-started containers
+
+**CI/CD Optimizations:**
+- Detects GitHub Actions environment via `GITHUB_ACTIONS` environment variable
+- Uses extended timeouts (10 seconds vs 3 seconds) for external instance detection in CI
+- Increases retry attempts and delays for slower CI environments
+- Adds initial delay after container start (5 seconds in CI, 2 seconds locally) for initialization scripts
+
 Enhanced LocalStack container management with comprehensive AWS service emulation:
 
 - **Service Emulation** - Full support for SQS (standard and FIFO), SNS, KMS, and IAM