Introducing cachemetrics package

cmd/pipecd/BUILD.bazel

@@ -26,6 +26,7 @@ go_library(
         "//pkg/app/ops/insightcollector:go_default_library",
         "//pkg/app/ops/mysqlensurer:go_default_library",
         "//pkg/app/ops/orphancommandcleaner:go_default_library",
+        "//pkg/cache/cachemetrics:go_default_library",
         "//pkg/cache/rediscache:go_default_library",
         "//pkg/cli:go_default_library",
         "//pkg/config:go_default_library",
@@ -45,6 +46,7 @@ go_library(
         "//pkg/version:go_default_library",
         "@com_github_dgrijalva_jwt_go//:go_default_library",
         "@com_github_nytimes_gziphandler//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_spf13_cobra//:go_default_library",
         "@org_golang_x_sync//errgroup:go_default_library",
         "@org_uber_go_zap//:go_default_library",

cmd/pipecd/server.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/NYTimes/gziphandler"
 	jwtgo "github.com/dgrijalva/jwt-go"
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/spf13/cobra"
 	"go.uber.org/zap"
 	"golang.org/x/sync/errgroup"
@@ -38,6 +39,7 @@ import (
 	"github.com/pipe-cd/pipe/pkg/app/api/pipedverifier"
 	"github.com/pipe-cd/pipe/pkg/app/api/service/webservice"
 	"github.com/pipe-cd/pipe/pkg/app/api/stagelogstore"
+	"github.com/pipe-cd/pipe/pkg/cache/cachemetrics"
 	"github.com/pipe-cd/pipe/pkg/cache/rediscache"
 	"github.com/pipe-cd/pipe/pkg/cli"
 	"github.com/pipe-cd/pipe/pkg/config"
@@ -130,6 +132,9 @@ func NewServerCommand() *cobra.Command {
 }
 
 func (s *server) run(ctx context.Context, t cli.Telemetry) error {
+	// Register all metrics.
+	registerMetrics()
+
 	group, ctx := errgroup.WithContext(ctx)
 
 	// Load control plane configuration from the specified file.
@@ -478,3 +483,8 @@ func createFilestore(ctx context.Context, cfg *config.ControlPlaneSpec, logger *
 		return nil, fmt.Errorf("unknown filestore type %q", cfg.Filestore.Type)
 	}
 }
+
+func registerMetrics() {
+	r := prometheus.DefaultRegisterer
+	cachemetrics.Register(r)
+}

manifests/pipecd/values.yaml

@@ -27,7 +27,7 @@ server:
     enableGRPCReflection: false
     secureCookie: false
     logEncoding: humanize
-    metrics: false
+    metrics: true
   resources: {}
   env: []
 

pkg/cache/cachemetrics/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["metrics.go"],
+    importpath = "github.com/pipe-cd/pipe/pkg/cache/cachemetrics",
+    visibility = ["//visibility:public"],
+    deps = ["@com_github_prometheus_client_golang//prometheus:go_default_library"],
+)

pkg/cache/cachemetrics/metrics.go

@@ -0,0 +1,62 @@
+// Copyright 2021 The PipeCD Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cachemetrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	statusKey = "status"
+	sourceKey = "source"
+)
+
+type StatusLabel string
+
+const (
+	LabelStatusHit  StatusLabel = "hit"
+	LabelStatusMiss StatusLabel = "miss"
+)
+
+type SourceLabel string
+
+const (
+	LabelSourceRedis    SourceLabel = "redis"
+	LabelSourceInmemory SourceLabel = "inmemory"
+)
+
+var (
+	getCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "controlplane_cache_get_operation_total",
+			Help: "Number of cache get operation while processing",
+		},
+		[]string{
+			statusKey,
+			sourceKey,
+		},
+	)
+)
+
+func Register(r prometheus.Registerer) {
+	r.MustRegister(getCounter)
+}
+
+func IncGetOperationCounter(status StatusLabel, source SourceLabel) {
+	getCounter.With(prometheus.Labels{
+		statusKey: string(status),
+		sourceKey: string(source),
+	}).Inc()
+}

pkg/cache/rediscache/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/cache:go_default_library",
+        "//pkg/cache/cachemetrics:go_default_library",
         "//pkg/redis:go_default_library",
         "@com_github_gomodule_redigo//redis:go_default_library",
     ],

pkg/cache/rediscache/cache.go

@@ -20,6 +20,7 @@ import (
 	redigo "github.com/gomodule/redigo/redis"
 
 	"github.com/pipe-cd/pipe/pkg/cache"
+	"github.com/pipe-cd/pipe/pkg/cache/cachemetrics"
 	"github.com/pipe-cd/pipe/pkg/redis"
 )
 
@@ -47,16 +48,32 @@ func (c *RedisCache) Get(k interface{}) (interface{}, error) {
 	reply, err := conn.Do("GET", k)
 	if err != nil {
 		if err == redigo.ErrNil {
+			cachemetrics.IncGetOperationCounter(
+				cachemetrics.LabelStatusMiss,
+				cachemetrics.LabelSourceRedis,
+			)
 			return nil, cache.ErrNotFound
 		}
 		return nil, err
 	}
 	if reply == nil {
+		cachemetrics.IncGetOperationCounter(
+			cachemetrics.LabelStatusMiss,
+			cachemetrics.LabelSourceRedis,
+		)
 		return nil, cache.ErrNotFound
 	}
 	if err, ok := reply.(redigo.Error); ok {
+		cachemetrics.IncGetOperationCounter(
+			cachemetrics.LabelStatusMiss,
+			cachemetrics.LabelSourceRedis,
+		)
 		return nil, err
 	}
+	cachemetrics.IncGetOperationCounter(
+		cachemetrics.LabelStatusHit,
+		cachemetrics.LabelSourceRedis,
+	)
 	return reply, nil
 }