From e7e18a8b654220820ad4fc964892d8a08f44e2ee Mon Sep 17 00:00:00 2001
From: Javan lacerda <javanlacerda@google.com>
Date: Thu, 11 Apr 2024 18:34:45 +0000
Subject: [PATCH] Adding grpc call for reading fulcio methods on prober

Signed-off-by: Javan lacerda <javanlacerda@google.com>
---
 cmd/prober/prober.go     | 40 +++++++++++++++++++++++++++++++---------
 cmd/prober/prometheus.go | 26 ++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 9 deletions(-)

diff --git a/cmd/prober/prober.go b/cmd/prober/prober.go
index 07ce49e1b..ee6ab6511 100644
--- a/cmd/prober/prober.go
+++ b/cmd/prober/prober.go
@@ -20,6 +20,7 @@ import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
+	"crypto/tls"
 	"encoding/json"
 	"flag"
 	"log"
@@ -32,7 +33,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	fulciopb "github.com/sigstore/fulcio/pkg/generated/protobuf"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/credentials"
 	"sigs.k8s.io/release-utils/version"
 
 	"github.com/sigstore/cosign/v2/cmd/cosign/cli/options"
@@ -118,7 +119,7 @@ func init() {
 
 	flag.StringVar(&rekorURL, "rekor-url", "https://rekor.sigstore.dev", "Set to the Rekor URL to run probers against")
 	flag.StringVar(&fulcioURL, "fulcio-url", "https://fulcio.sigstore.dev", "Set to the Fulcio URL to run probers against")
-	flag.StringVar(&fulcioGrpcURL, "fulcio-grpc-url", "grpc://fulcio.sigstore.dev", "Set to the Fulcio GRPC URL to run probers against")
+	flag.StringVar(&fulcioGrpcURL, "fulcio-grpc-url", "fulcio.sigstore.dev", "Set to the Fulcio GRPC URL to run probers against")
 
 	flag.BoolVar(&oneTime, "one-time", false, "Whether to run only one time and exit.")
 	flag.BoolVar(&runWriteProber, "write-prober", false, " [Kubernetes only] run the probers for the write endpoints.")
@@ -193,7 +194,7 @@ func main() {
 
 func NewFulcioClient() (fulciopb.CAClient, error) {
 	opts := []grpc.DialOption{grpc.WithUserAgent(options.UserAgent())}
-	transportCreds := insecure.NewCredentials()
+	transportCreds := credentials.NewTLS(&tls.Config{MinVersion: tls.VersionTLS12})
 	opts = append(opts, grpc.WithTransportCredentials(transportCreds))
 	conn, err := grpc.NewClient(fulcioGrpcURL, opts...)
 	if err != nil {
@@ -219,12 +220,12 @@ func runProbers(ctx context.Context, freq int, runOnce bool, fulcioGrpcClient fu
 			}
 		}
 
-		Logger.Infoln("Getting Bundle via grpc:", fulcioGrpcURL)
-		if resp, err := fulcioGrpcClient.GetTrustBundle(ctx, &fulciopb.GetTrustBundleRequest{}); err != nil {
-			hasErr = true
-			Logger.Errorf("error running request GetTrustBundle via gRPC: %v", err)
-		} else {
-			Logger.Infoln("Worked fine: %s", resp)
+		// Performing requests against Fulcio gRPC API
+		for _, method := range fulciopb.CA_ServiceDesc.Methods {
+			if err := observeGrcpRequest(ctx, method, fulcioGrpcClient); err != nil {
+				hasErr = true
+				Logger.Errorf("error running request %s: %v", method.MethodName, err)
+			}
 		}
 
 		if runWriteProber {
@@ -284,6 +285,27 @@ func observeRequest(host string, r ReadProberCheck) error {
 	return nil
 }
 
+func observeGrcpRequest(ctx context.Context, method grpc.MethodDesc, fulcioGrpcClient fulciopb.CAClient) error {
+	s := time.Now()
+
+	var err error
+	switch method.MethodName {
+	case "GetTrustBundle":
+		_, err = fulcioGrpcClient.GetTrustBundle(ctx, &fulciopb.GetTrustBundleRequest{})
+	case "GetConfiguration":
+		_, err = fulcioGrpcClient.GetConfiguration(ctx, &fulciopb.GetConfigurationRequest{})
+	default:
+		Logger.Warn("Unimplemented:", method.MethodName)
+		return nil
+	}
+	latency := time.Since(s).Milliseconds()
+	if err != nil {
+		return err
+	}
+	exportGrpcDataToPrometheus(fulcioGrpcURL, method.MethodName, latency)
+	return nil
+}
+
 func httpRequest(host string, r ReadProberCheck) (*retryablehttp.Request, error) {
 	req, err := retryablehttp.NewRequest(r.Method, host+r.Endpoint, bytes.NewBuffer([]byte(r.Body)))
 	if err != nil {
diff --git a/cmd/prober/prometheus.go b/cmd/prober/prometheus.go
index 891493d06..f5619cd78 100644
--- a/cmd/prober/prometheus.go
+++ b/cmd/prober/prometheus.go
@@ -49,6 +49,22 @@ var (
 	},
 		[]string{endpointLabel, hostLabel, statusCodeLabel, methodLabel})
 
+	grpcMethodLatenciesSummary = prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Name:       "api_endpoint_latency",
+			Help:       "API endpoint latency distributions (milliseconds).",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001, .999: 0.0001},
+		},
+		[]string{hostLabel, methodLabel},
+	)
+
+	grpcMethodLatenciesHistogram = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Name:    "api_endpoint_latency_histogram",
+		Help:    "API endpoint latency distribution across Rekor and Fulcio (milliseconds)",
+		Buckets: []float64{0.0, 200.0, 400.0, 600.0, 800.0, 1000.0},
+	},
+		[]string{hostLabel, methodLabel})
+
 	verificationCounter = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "verification",
@@ -72,6 +88,16 @@ func exportDataToPrometheus(resp *http.Response, host, endpoint, method string,
 	Logger.With(zap.Int("status", statusCode), zap.Int("bytes", int(resp.ContentLength)), zap.Duration("latency", time.Duration(latency)*time.Millisecond)).Infof("[DEBUG] %v %v", method, host+endpoint)
 }
 
+func exportGrpcDataToPrometheus(host string, method string, latency int64) {
+	labels := prometheus.Labels{
+		hostLabel:   host,
+		methodLabel: method,
+	}
+	grpcMethodLatenciesSummary.With(labels).Observe(float64(latency))
+	grpcMethodLatenciesHistogram.With(labels).Observe(float64(latency))
+	Logger.With(zap.Duration("latency", time.Duration(latency)*time.Millisecond)).Infof("[DEBUG] %v %v", method, host)
+}
+
 // NewVersionCollector returns a collector that exports metrics about current version
 // information.
 func NewVersionCollector(program string) prometheus.Collector {