Add custom Prometheus metrics

[iakmc]

Summary

• Added five custom Prometheus metrics
• Added internal/metrics/metrics_test.go for direct metric verification
• Added metric assertions to the existing HttpBinReconciler controller test

Metrics added

• httpbin_operator_httpbin_reconciled_total - counter, label: result (created/success/error). Incremented on every HttpBin reconcile call.
• httpbin_operator_deployments_total - counter, label: operation (created/updated/deleted). Tracks local Deployment lifecycle operations.
• httpbin_operator_services_total - counter, label: operation (created/updated). Tracks local Service lifecycle operations.
• httpbin_operator_deployment_ready - gauge, label: name. Set to 1 when the HttpBinDeployment has ready replicas, 0 otherwise. Removed when the HttpBinDeployment is deleted.
• httpbin_operator_ready_replicas - gauge, label: name. Tracks the current number of ready replicas per HttpBinDeployment. Removed when the HttpBinDeployment is deleted.

Testing

Unit test

go test ./internal/metrics/... -v -run TestMetricsManual

Manual test against a local kind cluster

kind create cluster --name httpbin-example

kubectl apply -f config/crd/gateway-api/
kubectl apply -f config/crd/bases/

go run cmd/main.go \
  --metrics-bind-address=:8080 \
  --metrics-secure=false \
  --health-probe-bind-address=:8082
Create a resource and check metrics:

kubectl apply -f - <<EOF
apiVersion: orchestrate.platform-mesh.io/v1alpha1
kind: HttpBin
metadata:
  name: demo
  namespace: default
spec:
  region: eu-west-1
EOF

curl -s http://localhost:8080/metrics | grep httpbin_operator
# HELP httpbin_operator_deployments_total Total number of local Deployment operations performed.
# TYPE httpbin_operator_deployments_total counter
httpbin_operator_deployments_total{operation="created"} 1
# HELP httpbin_operator_httpbin_reconciled_total Total number of HttpBin reconcile calls by result.
# TYPE httpbin_operator_httpbin_reconciled_total counter
httpbin_operator_httpbin_reconciled_total{result="created"} 1
httpbin_operator_httpbin_reconciled_total{result="success"} 3
# HELP httpbin_operator_services_total Total number of local Service operations performed.
# TYPE httpbin_operator_services_total counter
httpbin_operator_services_total{operation="created"} 1