16-June-25

Daily Quest #12: Observability & Monitoring

Observability & monitoring is key to understand about application and infrastructure healty in real-time

Reference :

• https://docs.github.com/en/actions/use-cases-and-examples/using-containerized-services/about-service-containers

Real world usecase : Before deploying application in production, devops team scrape request latency and error rate in 30Second. if error rate > 1% deployment canceled

We use feature on github workflows called service_containers, you can use other tools using docker container that provide a simple and portable way for you to host services you might need to test or operate your application in a workflow.

Skenario : Integrate prometheus service in github actions, scrape basic metrics, and save snapshot using artefacts

1. Create folder /monitoring with prometheus.yml and docker-compose.yaml

global:
  scrape_interval: 5s
scrape_configs:
  - job_name: 'ci-cd-demo'
    static_configs:
    - targets:
      - 'localhost:9090'

name: Observability & monitoring
on:
  push:
jobs:
  observe:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Running prometheus container
        run: |
          docker run -d \
            --name prometheus \
            -p 9090:9090 \
            -v ${{ github.workspace }}/monitoring/prometheus.yml:/etc/prometheus/prometheus.yml \
            prom/prometheus:latest \
            --config.file=/etc/prometheus/prometheus.yml \
            --web.listen-address=:9090
      - name: Wait prometheus to be ready
        run: |
          echo "Waiting for Prometheus to be ready..."
          sleep 30s
          docker logs prometheus
          echo "Prometheus should be ready now."

      - name: Run Prometheus
        run: |
          echo "scrape metrics"
          curl http://localhost:9090/metrics | head -n 10 > prometheus_metrics.txt

      - name: Upload metrics to artifact
        uses: actions/upload-artifact@v4
        with:
          name: prometheus-metrics
          path: prometheus_metrics.txt 

2. Push and see result

# HELP go_gc_cycles_automatic_gc_cycles_total Count of completed GC cycles generated by the Go runtime. Sourced from /gc/cycles/automatic:gc-cycles.
# TYPE go_gc_cycles_automatic_gc_cycles_total counter
go_gc_cycles_automatic_gc_cycles_total 6
# HELP go_gc_cycles_forced_gc_cycles_total Count of completed GC cycles forced by the application. Sourced from /gc/cycles/forced:gc-cycles.
# TYPE go_gc_cycles_forced_gc_cycles_total counter
go_gc_cycles_forced_gc_cycles_total 0
# HELP go_gc_cycles_total_gc_cycles_total Count of all completed GC cycles. Sourced from /gc/cycles/total:gc-cycles.
# TYPE go_gc_cycles_total_gc_cycles_total counter
go_gc_cycles_total_gc_cycles_total 6
# HELP go_gc_duration_seconds A summary of the wall-time pause (stop-the-world) duration in garbage collection cycles.

Answer (jelaskan dong):

1. Scrape lebih unggul untuk mendapatkan data dari hal yang dimonitoring
2. Snapshot metrik dapat digunakan sebagai acuan dalam mendesign grafana dashboard