feat: Update Helm chart and CI for exporter enhancements

This commit introduces updates to the Helm chart to support log level
configuration for the iperf3 exporter, and modifies the CI workflow
to improve image tagging for pull requests.

Helm Chart Changes (`charts/iperf3-monitor`):
- Added `exporter.logLevel` to `values.yaml` (default: "INFO") to allow
  you to set the exporter's log level.
- Updated `templates/exporter-deployment.yaml` to use the
  `exporter.logLevel` value to set the `LOG_LEVEL` environment
  variable in the exporter container.

CI Workflow Changes (`.github/workflows/ci.yaml`):
- Modified the Docker image build process to tag images built from
  pull requests with `pr-<PR_NUMBER>`.
- Ensured that these PR-specific images are pushed to the container
  registry.
- Preserved existing tagging mechanisms (e.g., SHA-based tags).

.github/workflows/ci.yaml

@@ -42,12 +42,21 @@ jobs:
         uses: docker/metadata-action@v4
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            # Tag with the PR number if it's a pull request event
+            type=match,pattern=pull_request,value=pr-{{number}}
+            # Tag with the git SHA
+            type=sha,prefix=
+            # Tag with 'latest' if on the main branch (though this workflow only runs on PRs to main)
+            type=ref,event=branch,pattern=main,value=latest
 
       - name: Build Docker image
         uses: docker/build-push-action@v4
         with:
           context: ./exporter
-          push: false # Do not push on PRs
+          # Push the image if the event is a pull request.
+          # The workflow currently only triggers on pull_request events.
+          push: ${{ github.event_name == 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           platforms: linux/amd64,linux/arm64

charts/iperf3-monitor/templates/exporter-deployment.yaml

@@ -34,6 +34,8 @@ spec:
           value: "{{ .Values.exporter.testInterval }}"
         - name: IPERF_TEST_PROTOCOL
           value: "{{ .Values.exporter.testProtocol }}"
+        - name: LOG_LEVEL
+          value: "{{ .Values.exporter.logLevel }}"
         - name: IPERF_SERVER_PORT
           value: "5201" # Hardcoded as per server DaemonSet
         - name: IPERF_SERVER_NAMESPACE

charts/iperf3-monitor/values.yaml

@@ -24,6 +24,9 @@ exporter:
   # -- Interval in seconds between complete test cycles (i.e., testing all server nodes).
   testInterval: 300
 
+  # -- Log level for the iperf3 exporter (e.g., DEBUG, INFO, WARNING, ERROR, CRITICAL).
+  logLevel: INFO
+
   # -- Timeout in seconds for a single iperf3 test run.
   testTimeout: 10