[telemetrygen] support --service for all signal types (#38044)

This flag was supported only for traces. It's possible to set the
service name via `--otlp-attributes`, but it's more convenient to be
able to set it via `--service`. I added it to all signals, but if others
disagree with this change, then I would suggest we remove it from all
signals.

---------

Signed-off-by: Alex Boten <[email protected]>

Author: codeboten

.chloggen/codeboten_telemetrygen-servicename.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# 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: Support `--service` for all signal types, rather than just traces
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [38044]
+
+# (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:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

cmd/telemetrygen/internal/common/config.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/spf13/pflag"
 	"go.opentelemetry.io/otel/attribute"
+	semconv "go.opentelemetry.io/otel/semconv/v1.25.0"
 )
 
 var (
@@ -72,6 +73,7 @@ type Config struct {
 	HTTPPath            string
 	Headers             KeyValue
 	ResourceAttributes  KeyValue
+	ServiceName         string
 	TelemetryAttributes KeyValue
 
 	// OTLP TLS configuration
@@ -102,6 +104,8 @@ func (c *Config) Endpoint() string {
 func (c *Config) GetAttributes() []attribute.KeyValue {
 	var attributes []attribute.KeyValue
 
+	// may be overridden by `--otlp-attributes service.name="foo"`
+	attributes = append(attributes, semconv.ServiceNameKey.String(c.ServiceName))
 	if len(c.ResourceAttributes) > 0 {
 		for k, t := range c.ResourceAttributes {
 			switch v := t.(type) {
@@ -158,6 +162,8 @@ func (c *Config) CommonFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&c.InsecureSkipVerify, "otlp-insecure-skip-verify", c.InsecureSkipVerify, "Whether a client verifies the server's certificate chain and host name")
 	fs.BoolVar(&c.UseHTTP, "otlp-http", c.UseHTTP, "Whether to use HTTP exporter rather than a gRPC one")
 
+	fs.StringVar(&c.ServiceName, "service", c.ServiceName, "Service name to use")
+
 	// custom headers
 	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\". "+
 		"Note you may need to escape the quotes when using the tool from a cli. "+
@@ -198,6 +204,7 @@ func (c *Config) SetDefaults() {
 	c.HTTPPath = ""
 	c.Headers = make(KeyValue)
 	c.ResourceAttributes = make(KeyValue)
+	c.ServiceName = "telemetrygen"
 	c.TelemetryAttributes = make(KeyValue)
 	c.CaFile = ""
 	c.ClientAuth.Enabled = false

cmd/telemetrygen/pkg/traces/config.go

@@ -18,7 +18,6 @@ type Config struct {
 	NumTraces        int
 	NumChildSpans    int
 	PropagateContext bool
-	ServiceName      string
 	StatusCode       string
 	Batch            bool
 	LoadSize         int
@@ -41,7 +40,6 @@ func (c *Config) Flags(fs *pflag.FlagSet) {
 	fs.IntVar(&c.NumTraces, "traces", c.NumTraces, "Number of traces to generate in each worker (ignored if duration is provided)")
 	fs.IntVar(&c.NumChildSpans, "child-spans", c.NumChildSpans, "Number of child spans to generate for each trace")
 	fs.BoolVar(&c.PropagateContext, "marshal", c.PropagateContext, "Whether to marshal trace context via HTTP headers")
-	fs.StringVar(&c.ServiceName, "service", c.ServiceName, "Service name to use")
 	fs.StringVar(&c.StatusCode, "status-code", c.StatusCode, "Status code to use for the spans, one of (Unset, Error, Ok) or the equivalent integer (0,1,2)")
 	fs.BoolVar(&c.Batch, "batch", c.Batch, "Whether to batch traces")
 	fs.IntVar(&c.LoadSize, "size", c.LoadSize, "Desired minimum size in MB of string data for each trace generated. This can be used to test traces with large payloads, i.e. when testing the OTLP receiver endpoint max receive size.")
@@ -57,7 +55,6 @@ func (c *Config) SetDefaults() {
 	c.NumTraces = 1
 	c.NumChildSpans = 1
 	c.PropagateContext = false
-	c.ServiceName = "telemetrygen"
 	c.StatusCode = "0"
 	c.Batch = true
 	c.LoadSize = 0

cmd/telemetrygen/pkg/traces/traces.go

@@ -80,8 +80,6 @@ func Start(cfg *Config) error {
 	}
 
 	var attributes []attribute.KeyValue
-	// may be overridden by `--otlp-attributes service.name="foo"`
-	attributes = append(attributes, semconv.ServiceNameKey.String(cfg.ServiceName))
 	attributes = append(attributes, cfg.GetAttributes()...)
 
 	tracerProvider := sdktrace.NewTracerProvider(