[cmd/telemetrygen] create a simple counter metric generator

.chloggen/telemetrygen-metrics.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: telemetrygen
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Implement a simple metric generation command for telemetrygen
+
+# One or more tracking issues related to the change
+issues: [17986]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

cmd/telemetrygen/config.go

@@ -16,15 +16,18 @@
 package main // import "github.com/open-telemetry/opentelemetry-collector-contrib/telemetrygen/internal/telemetrygen"
 
 import (
-	"errors"
 	"os"
 
 	"github.com/spf13/cobra"
 
+	"github.com/open-telemetry/opentelemetry-collector-contrib/cmd/telemetrygen/internal/metrics"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/cmd/telemetrygen/internal/traces"
 )
 
-var tracesCfg *traces.Config
+var (
+	tracesCfg  *traces.Config
+	metricsCfg *metrics.Config
+)
 
 // rootCmd is the root command on which will be run children commands
 var rootCmd = &cobra.Command{
@@ -49,8 +52,7 @@ var metricsCmd = &cobra.Command{
 	Short:   "Simulates a client generating metrics",
 	Example: "telemetrygen metrics",
 	RunE: func(cmd *cobra.Command, args []string) error {
-		err := errors.New("[WIP] The 'metrics' command is a work in progress, come back later")
-		return err
+		return metrics.Start(metricsCfg)
 	},
 }
 
@@ -60,6 +62,9 @@ func init() {
 	tracesCfg = new(traces.Config)
 	tracesCfg.Flags(tracesCmd.Flags())
 
+	metricsCfg = new(metrics.Config)
+	metricsCfg.Flags(metricsCmd.Flags())
+
 	// Disabling completion command for end user
 	// https://github.com/spf13/cobra/blob/master/shell_completions.md
 	rootCmd.CompletionOptions.DisableDefaultCmd = true

cmd/telemetrygen/go.mod

@@ -7,11 +7,15 @@ require (
 	github.com/spf13/cobra v1.6.1
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.1
+	go.opentelemetry.io/collector/semconv v0.71.0
 	go.opentelemetry.io/otel v1.13.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v0.36.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v0.36.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.13.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.13.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.13.0
 	go.opentelemetry.io/otel/sdk v1.13.0
+	go.opentelemetry.io/otel/sdk/metric v0.36.0
 	go.opentelemetry.io/otel/trace v1.13.0
 	go.uber.org/atomic v1.10.0
 	go.uber.org/zap v1.24.0
@@ -29,6 +33,8 @@ require (
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.13.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.36.0 // indirect
+	go.opentelemetry.io/otel/metric v0.36.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
 	golang.org/x/net v0.4.0 // indirect

cmd/telemetrygen/internal/common/config.go

@@ -0,0 +1,102 @@
+// Copyright The OpenTelemetry 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 common
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/spf13/pflag"
+	"go.opentelemetry.io/otel/attribute"
+)
+
+var (
+	errFormatOTLPAttributes       = fmt.Errorf("value should be of the format key=\"value\"")
+	errDoubleQuotesOTLPAttributes = fmt.Errorf("value should be a string wrapped in double quotes")
+)
+
+type KeyValue map[string]string
+
+var _ pflag.Value = (*KeyValue)(nil)
+
+func (v *KeyValue) String() string {
+	return ""
+}
+
+func (v *KeyValue) Set(s string) error {
+	kv := strings.SplitN(s, "=", 2)
+	if len(kv) != 2 {
+		return errFormatOTLPAttributes
+	}
+	val := kv[1]
+	if len(val) < 2 || !strings.HasPrefix(val, "\"") || !strings.HasSuffix(val, "\"") {
+		return errDoubleQuotesOTLPAttributes
+	}
+
+	(*v)[kv[0]] = val[1 : len(val)-1]
+	return nil
+}
+
+func (v *KeyValue) Type() string {
+	return "map[string]string"
+}
+
+type Config struct {
+	WorkerCount       int
+	Rate              int64
+	TotalDuration     time.Duration
+	ReportingInterval time.Duration
+
+	// OTLP config
+	Endpoint           string
+	Insecure           bool
+	UseHTTP            bool
+	Headers            KeyValue
+	ResourceAttributes KeyValue
+}
+
+func (c *Config) GetAttributes() []attribute.KeyValue {
+	var attributes []attribute.KeyValue
+
+	if len(c.ResourceAttributes) > 0 {
+		for k, v := range c.ResourceAttributes {
+			attributes = append(attributes, attribute.String(k, v))
+		}
+	}
+	return attributes
+}
+
+// CommonFlags registers common config flags.
+func (c *Config) CommonFlags(fs *pflag.FlagSet) {
+	fs.IntVar(&c.WorkerCount, "workers", 1, "Number of workers (goroutines) to run")
+	fs.Int64Var(&c.Rate, "rate", 0, "Approximately how many metrics per second each worker should generate. Zero means no throttling.")
+	fs.DurationVar(&c.TotalDuration, "duration", 0, "For how long to run the test")
+	fs.DurationVar(&c.ReportingInterval, "interval", 1*time.Second, "Reporting interval (default 1 second)")
+
+	fs.StringVar(&c.Endpoint, "otlp-endpoint", "localhost:4317", "Target to which the exporter is going to send metrics. This MAY be configured to include a path (e.g. example.com/v1/metrics)")
+	fs.BoolVar(&c.Insecure, "otlp-insecure", false, "Whether to enable client transport security for the exporter's grpc or http connection")
+	fs.BoolVar(&c.UseHTTP, "otlp-http", false, "Whether to use HTTP exporter rather than a gRPC one")
+
+	// custom headers
+	c.Headers = make(map[string]string)
+	fs.Var(&c.Headers, "otlp-header", "Custom header to be passed along with each OTLP request. The value is expected in the format key=value."+
+		"Flag may be repeated to set multiple headers (e.g -otlp-header key1=value1 -otlp-header key2=value2)")
+
+	// custom resource attributes
+	c.ResourceAttributes = make(map[string]string)
+	fs.Var(&c.ResourceAttributes, "otlp-attributes", "Custom resource attributes to use. The value is expected in the format key=\"value\"."+
+		"Flag may be repeated to set multiple attributes (e.g -otlp-attributes key1=\"value1\" -otlp-attributes key2=\"value2\")")
+}

cmd/telemetrygen/internal/traces/config_test.go → cmd/telemetrygen/internal/common/config_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package traces
+package common
 
 import (
 	"testing"

cmd/telemetrygen/internal/common/log.go

@@ -0,0 +1,34 @@
+// Copyright The OpenTelemetry 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 common
+
+import (
+	"fmt"
+
+	grpcZap "github.com/grpc-ecosystem/go-grpc-middleware/logging/zap"
+	"go.uber.org/zap"
+)
+
+// CreateLogger creates a logger for use by telemetrygen
+func CreateLogger() (*zap.Logger, error) {
+	logger, err := zap.NewDevelopment()
+	if err != nil {
+		return nil, fmt.Errorf("failed to obtain logger: %w", err)
+	}
+	grpcZap.ReplaceGrpcLoggerV2(logger.WithOptions(
+		zap.AddCallerSkip(3),
+	))
+	return logger, err
+}

cmd/telemetrygen/internal/metrics/config.go

@@ -0,0 +1,33 @@
+// Copyright The OpenTelemetry 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 metrics
+
+import (
+	"github.com/spf13/pflag"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/cmd/telemetrygen/internal/common"
+)
+
+// Config describes the test scenario.
+type Config struct {
+	common.Config
+	NumMetrics int
+}
+
+// Flags registers config flags.
+func (c *Config) Flags(fs *pflag.FlagSet) {
+	c.CommonFlags(fs)
+	fs.IntVar(&c.NumMetrics, "metrics", 1, "Number of metrics to generate in each worker (ignored if duration is provided)")
+}