Merge branch 'prometheus-integration' into 'master'

Prometheus integration

See merge request !62

config/configs.go

@@ -37,6 +37,9 @@ var EntitiesManagerUrl string
 var CertDir string
 var GlobalLogLevel string
 
+var PrometeusListenAddress string
+var MetricEnvPrefix string
+
 func SetConfigValues(configFile, etcdURL string) {
 	// Set Default Values For Config Variables
 
@@ -141,12 +144,17 @@ func SetConfigValues(configFile, etcdURL string) {
 
 	MaxMessageSize = viper.GetInt("maxMessageSize")
 
+	PrometeusListenAddress = viper.GetString("prometeusListenAddress")
+
+	MetricEnvPrefix = viper.GetString("metricEnvPrefix")
+
+	GlobalLogLevel = viper.GetString("globalLogLevel")
+
 	CertificatePEM = GetCertificatePEM()
 	PrivateKeyPEM = GetPrivateKeyPEM()
 	CaCertificatePEM = GetCaCertificatePEM()
 	VereignCaCertificatePEM = GetVereignCaCertificatePEM()
 	VereignCaKeyPEM = GetVereignCaKeyPEM()
-	GlobalLogLevel = viper.GetString("globalLogLevel")
 }
 
 func GetCertificatePEM() []byte {

main.go

@@ -70,6 +70,13 @@ func main() {
 		}
 	}()
 
+	go func() {
+		err := server.StartPrometheusServer()
+		if err != nil {
+			log.Printf("failed to start prometheus server: %v", err)
+		}
+	}()
+
 	// infinite loop
 	log.Printf("Entering infinite loop")
 	select {}

server/server.go

@@ -18,13 +18,18 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
 import (
-	"code.vereign.com/code/viam-apis/errors"
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
 	"net"
 	"net/http"
 	"strings"
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+
+	"code.vereign.com/code/viam-apis/errors"
 
 	"code.vereign.com/code/viam-apis/log"
 
@@ -41,6 +46,9 @@ import (
 	"google.golang.org/grpc/metadata"
 )
 
+var mutex sync.RWMutex
+var summaries = make(map[string]prometheus.Summary)
+
 // private type for Context keys
 type contextKey int
 
@@ -112,6 +120,40 @@ func unaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServ
 	return res, err
 }
 
+func createQueryTime(funcName string) prometheus.Summary {
+	if config.PrometeusListenAddress != "" {
+		endPointName := strings.Replace(funcName, "/", "_", -1)
+		endPointName = strings.Replace(endPointName, ".", "_", -1)
+
+		metricName := endPointName + "_grpc_request_duration_seconds"
+
+		if config.MetricEnvPrefix != "" {
+			metricName = config.MetricEnvPrefix + "_" + metricName
+		}
+
+		mutex.Lock()
+		defer mutex.Unlock()
+
+		queryTime, ok := summaries[metricName]
+
+		if ok == false {
+			queryTime = prometheus.NewSummary(prometheus.SummaryOpts{
+				Name: metricName,
+				Help: "grpc request duration seconds of /" + funcName + " for " + config.MetricEnvPrefix + " env",
+			})
+
+			// init metrics
+			prometheus.MustRegister(queryTime)
+
+			summaries[metricName] = queryTime
+		}
+
+		return queryTime
+	}
+
+	return nil
+}
+
 func StartGRPCServer(address string, certPEM, privateKeyPEM, caCertPEM, vereignCertPEM, vereignPrivateKeyPEM []byte, dataStorageAddress string, maxMessageSize int) error {
 	pkgCertPEM = certPEM
 	pkgKeyPEM = privateKeyPEM
@@ -217,3 +259,19 @@ func StartRESTServer(address, grpcAddress string, certPEM []byte) error {
 
 	return nil
 }
+
+func StartPrometheusServer() error {
+	if config.PrometeusListenAddress != "" {
+		// start prometheus
+		promHandler := http.NewServeMux()
+		promHandler.Handle("/metrics", promhttp.Handler())
+		log.Println("Starting prometheus...")
+		err := http.ListenAndServe(config.PrometeusListenAddress, promHandler)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}