set up ci and prometheus metrics

Author: MohamedAklamaash

.github/workflows/ci.yml

@@ -0,0 +1,40 @@
+name: ci
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    services:
+      redis:
+        image: redis:7-alpine
+        ports:
+          - 6379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+      - run: go vet ./...
+      - run: go build ./...
+      - run: go test -race ./...
+        env:
+          RELAY_REDIS_ADDR: 127.0.0.1:6379
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+      - name: gofmt
+        run: test -z "$(gofmt -l .)"

metrics.go

@@ -0,0 +1,52 @@
+package relay
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+	tasksProcessed = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "relay",
+		Name:      "tasks_processed_total",
+		Help:      "Number of tasks processed successfully.",
+	}, []string{"queue", "type"})
+
+	tasksFailed = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "relay",
+		Name:      "tasks_failed_total",
+		Help:      "Number of task executions that returned an error.",
+	}, []string{"queue", "type"})
+
+	tasksRetried = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "relay",
+		Name:      "tasks_retried_total",
+		Help:      "Number of tasks scheduled for retry.",
+	}, []string{"queue", "type"})
+
+	tasksArchived = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "relay",
+		Name:      "tasks_archived_total",
+		Help:      "Number of tasks moved to the archive after exhausting retries.",
+	}, []string{"queue", "type"})
+
+	tasksInProgress = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "relay",
+		Name:      "tasks_in_progress",
+		Help:      "Number of tasks currently being processed.",
+	}, []string{"queue"})
+
+	processingDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "relay",
+		Name:      "task_duration_seconds",
+		Help:      "Time spent processing a task.",
+		Buckets:   prometheus.DefBuckets,
+	}, []string{"queue", "type"})
+)
+
+func MetricsHandler() http.Handler {
+	return promhttp.Handler()
+}