Merge pull request #8 from microservices-demo/monitoring/prometheus

Added prometheus monitoring.

.travis.yml

@@ -13,7 +13,9 @@ before_install:
   - go get github.com/go-kit/kit/log 
   - go get github.com/go-kit/kit/endpoint 
   - go get github.com/go-kit/kit/transport/http 
-  - go get github.com/go-sql-driver/mysql 
+  - go get github.com/go-kit/kit/metrics/prometheus
+  - go get github.com/prometheus/client_golang/prometheus
+  - go get github.com/go-sql-driver/mysql
   - go get github.com/jmoiron/sqlx
   - go get gopkg.in/DATA-DOG/go-sqlmock.v1
 

cmd/cataloguesvc/main.go

@@ -8,6 +8,8 @@ import (
 	"syscall"
 
 	"github.com/go-kit/kit/log"
+	kitprometheus "github.com/go-kit/kit/metrics/prometheus"
+	stdprometheus "github.com/prometheus/client_golang/prometheus"
 
 	"net/http"
 
@@ -60,11 +62,29 @@ func main() {
 		logger.Log("Error", "Unable to connect to Database", "DSN", dsn)
 	}
 
+	fieldKeys := []string{"method"}
 	// Service domain.
 	var service catalogue.Service
 	{
 		service = catalogue.NewCatalogueService(db, logger)
 		service = catalogue.LoggingMiddleware(logger)(service)
+		service = catalogue.NewInstrumentingService(
+			kitprometheus.NewCounterFrom(
+				stdprometheus.CounterOpts{
+					Namespace: "microservices_demo",
+					Subsystem: "catalogue",
+					Name:      "request_count",
+					Help:      "Number of requests received.",
+				},
+				fieldKeys),
+			kitprometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
+				Namespace: "microservices_demo",
+				Subsystem: "catalogue",
+				Name:      "request_latency_microseconds",
+				Help:      "Total duration of requests in microseconds.",
+			}, fieldKeys),
+			service,
+		)
 	}
 
 	// Endpoint domain.

docker/catalogue/Dockerfile

@@ -4,10 +4,10 @@ RUN mkdir /app
 COPY . /go/src/github.com/microservices-demo/catalogue/
 COPY images/ /app/images/
 
-RUN go get github.com/gorilla/mux github.com/go-kit/kit/log github.com/go-kit/kit/endpoint github.com/go-kit/kit/transport/http github.com/go-sql-driver/mysql github.com/jmoiron/sqlx
+RUN go get github.com/gorilla/mux github.com/go-kit/kit/log github.com/go-kit/kit/endpoint github.com/go-kit/kit/transport/http github.com/go-sql-driver/mysql github.com/jmoiron/sqlx github.com/go-kit/kit/metrics/prometheus github.com/prometheus/client_golang/prometheus
 
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o /app/main github.com/microservices-demo/catalogue/cmd/cataloguesvc
 
 CMD ["/app/main", "-port=80"]
 
-EXPOSE 80
+EXPOSE 80

middlewares.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/metrics"
 )
 
 // Middleware decorates a service.
@@ -78,3 +79,54 @@ func (mw loggingMiddleware) Tags() (tags []string, err error) {
 	}(time.Now())
 	return mw.next.Tags()
 }
+
+type instrumentingService struct {
+	requestCount   metrics.Counter
+	requestLatency metrics.Histogram
+	Service
+}
+
+// NewInstrumentingService returns an instance of an instrumenting Service.
+func NewInstrumentingService(requestCount metrics.Counter, requestLatency metrics.Histogram, s Service) Service {
+	return &instrumentingService{
+		requestCount:   requestCount,
+		requestLatency: requestLatency,
+		Service:        s,
+	}
+}
+
+func (s *instrumentingService) List(tags []string, order string, pageNum, pageSize int) ([]Sock, error) {
+	defer func(begin time.Time) {
+		s.requestCount.With("method", "list").Add(1)
+		s.requestLatency.With("method", "list").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return s.Service.List(tags, order, pageNum, pageSize)
+}
+
+func (s *instrumentingService) Count(tags []string) (int, error) {
+	defer func(begin time.Time) {
+		s.requestCount.With("method", "count").Add(1)
+		s.requestLatency.With("method", "count").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return s.Service.Count(tags)
+}
+
+func (s *instrumentingService) Get(id string) (Sock, error) {
+	defer func(begin time.Time) {
+		s.requestCount.With("method", "get").Add(1)
+		s.requestLatency.With("method", "get").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return s.Service.Get(id)
+}
+
+func (s *instrumentingService) Tags() ([]string, error) {
+	defer func(begin time.Time) {
+		s.requestCount.With("method", "tags").Add(1)
+		s.requestLatency.With("method", "tags").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return s.Service.Tags()
+}

transport.go

@@ -12,6 +12,7 @@ import (
 	"github.com/go-kit/kit/log"
 	httptransport "github.com/go-kit/kit/transport/http"
 	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/net/context"
 )
 
@@ -68,6 +69,7 @@ func MakeHTTPHandler(ctx context.Context, e Endpoints, imagePath string, logger
 		encodeHealthResponse,
 		options...,
 	))
+	r.Handle("/metrics", promhttp.Handler())
 	return r
 }