Add tool to check unmapped fields in Alloy (#1723)

Author: marctc

.github/workflows/config-checker.yml

@@ -0,0 +1,141 @@
+name: Alloy Mapped Fields Checker
+
+on:
+  push:
+    branches: [ main ]
+    paths:
+      - 'pkg/**/*.go'
+
+jobs:
+  check-config:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      contents: read
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version-file: 'go.mod'
+        cache: false  # Disable caching to avoid extraction conflicts
+        check-latest: true
+
+    - name: Run alloy field checker
+      id: field-checker
+      run: |
+        # First compile the checker to ensure it builds
+        cd tools/alloy-field-checker
+        go build -o field-checker
+        if [ $? -ne 0 ]; then
+          echo "Failed to build field checker"
+          exit 1
+        fi
+        
+        # Move back to workspace root and run the checker
+        cd ../..
+        if [ ! -d "pkg" ]; then
+          echo "pkg directory not found in $(pwd)"
+          ls -la
+          exit 1
+        fi
+        
+        tools/alloy-field-checker/field-checker 2>&1 | tee output.txt
+        if [ ${PIPESTATUS[0]} -ne 0 ]; then
+          # Create a normalized version of the output (remove line numbers which can change)
+          grep "unmapped fields:" output.txt > /dev/null && {
+            echo "has_unmapped=true" >> $GITHUB_OUTPUT
+            echo "unmapped_fields<<EOF" >> $GITHUB_OUTPUT
+            # Extract just the field names and struct names, ignore line numbers
+            grep -o "[a-zA-Z0-9]\+\.[a-zA-Z0-9]\+ (tag: [^)]\+)" output.txt | sort > normalized_output.txt
+            cat normalized_output.txt >> $GITHUB_OUTPUT
+            echo "EOF" >> $GITHUB_OUTPUT
+          } || {
+            echo "has_unmapped=false" >> $GITHUB_OUTPUT
+          }
+        else
+          echo "has_unmapped=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: Find existing issues
+      if: steps.field-checker.outputs.has_unmapped == 'true'
+      uses: actions/github-script@v7
+      id: find-issue
+      with:
+        script: |
+          const issues = await github.rest.issues.listForRepo({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            state: 'open',
+            labels: []
+          });
+          const existingIssue = issues.data.find(issue => 
+            issue.title === 'Map missing Beyla options in Alloy component'
+          );
+          return existingIssue ? existingIssue.number : 0;
+        result-encoding: string
+
+    - name: Manage issue
+      if: steps.field-checker.outputs.has_unmapped == 'true'
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const issueNumber = parseInt('${{ steps.find-issue.outputs.result }}');
+          const issueBody = `Unmapped configuration fields were detected in Beyla's Alloy component:
+
+          \`\`\`
+          ${process.env.UNMAPPED_FIELDS}
+          \`\`\`
+
+          Please ensure all configuration fields are properly mapped in the Alloy configuration.
+          
+          This issue was automatically generated by the config-checker workflow.`;
+
+          if (issueNumber > 0) {
+            // Update existing issue
+            await github.rest.issues.update({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber,
+              body: issueBody
+            });
+          } else {
+            // Create new issue
+            await github.rest.issues.create({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              title: 'Map missing Beyla options in Alloy component',
+              body: issueBody,
+              assignee: context.repo.owner
+            });
+          }
+      env:
+        UNMAPPED_FIELDS: ${{ steps.field-checker.outputs.unmapped_fields }}
+
+    - name: Close issue if no unmapped fields
+      if: steps.field-checker.outputs.has_unmapped == 'false'
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const issues = await github.rest.issues.listForRepo({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            state: 'open',
+            labels: []
+          });
+          
+          const existingIssue = issues.data.find(issue => 
+            issue.title === 'Map missing Beyla options in Alloy component'
+          );
+          
+          if (existingIssue) {
+            await github.rest.issues.update({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: existingIssue.number,
+              state: 'closed',
+              state_reason: 'completed'
+            });
+          }