[exporter/zipkin] use confighttp.DefaultHTTPClientSettings (open-tele…

…metry#29931)

**Description:**
Modernize the logic of validation by moving to config Validate from the
Start function
Use the HTTPClientDefaultSettings defaults when setting the config.

**Link to tracking Issue:**
open-telemetry#6641

**Testing:**
Updated tests.

.chloggen/zipkinexporter_clientsettings.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: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: zipkinexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Use default client HTTP settings in zipkinexporter, move validation to config validation
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29931]
+
+# (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: []

exporter/zipkinexporter/config.go

@@ -4,6 +4,8 @@
 package zipkinexporter // import "github.com/open-telemetry/opentelemetry-collector-contrib/exporter/zipkinexporter"
 
 import (
+	"errors"
+
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/confighttp"
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
@@ -27,5 +29,8 @@ var _ component.Config = (*Config)(nil)
 
 // Validate checks if the exporter configuration is valid
 func (cfg *Config) Validate() error {
+	if cfg.HTTPClientSettings.Endpoint == "" {
+		return errors.New("endpoint required")
+	}
 	return nil
 }

exporter/zipkinexporter/config_test.go

@@ -29,6 +29,8 @@ func TestLoadConfig(t *testing.T) {
 	// URL doesn't have a default value so set it directly.
 	defaultCfg := createDefaultConfig().(*Config)
 	defaultCfg.Endpoint = "http://some.location.org:9411/api/v2/spans"
+	maxIdleConns := 50
+	idleConnTimeout := 5 * time.Second
 
 	tests := []struct {
 		id       component.ID
@@ -61,6 +63,8 @@ func TestLoadConfig(t *testing.T) {
 					TLSSetting: configtls.TLSClientSetting{
 						InsecureSkipVerify: true,
 					},
+					MaxIdleConns:    &maxIdleConns,
+					IdleConnTimeout: &idleConnTimeout,
 				},
 				Format:             "proto",
 				DefaultServiceName: "test_name",

exporter/zipkinexporter/factory.go

@@ -5,7 +5,6 @@ package zipkinexporter // import "github.com/open-telemetry/opentelemetry-collec
 
 import (
 	"context"
-	"errors"
 	"time"
 
 	"go.opentelemetry.io/collector/component"
@@ -33,14 +32,13 @@ func NewFactory() exporter.Factory {
 }
 
 func createDefaultConfig() component.Config {
+	defaultClientHTTPSettings := confighttp.NewDefaultHTTPClientSettings()
+	defaultClientHTTPSettings.Timeout = defaultTimeout
+	defaultClientHTTPSettings.WriteBufferSize = 512 * 1024
 	return &Config{
-		RetrySettings: exporterhelper.NewDefaultRetrySettings(),
-		QueueSettings: exporterhelper.NewDefaultQueueSettings(),
-		HTTPClientSettings: confighttp.HTTPClientSettings{
-			Timeout: defaultTimeout,
-			// We almost read 0 bytes, so no need to tune ReadBufferSize.
-			WriteBufferSize: 512 * 1024,
-		},
+		RetrySettings:      exporterhelper.NewDefaultRetrySettings(),
+		QueueSettings:      exporterhelper.NewDefaultQueueSettings(),
+		HTTPClientSettings: defaultClientHTTPSettings,
 		Format:             defaultFormat,
 		DefaultServiceName: defaultServiceName,
 	}
@@ -53,11 +51,6 @@ func createTracesExporter(
 ) (exporter.Traces, error) {
 	zc := cfg.(*Config)
 
-	if zc.Endpoint == "" {
-		// TODO https://github.com/open-telemetry/opentelemetry-collector/issues/215
-		return nil, errors.New("exporter config requires a non-empty 'endpoint'")
-	}
-
 	ze, err := createZipkinExporter(zc, set.TelemetrySettings)
 	if err != nil {
 		return nil, err

exporter/zipkinexporter/factory_test.go

@@ -21,16 +21,10 @@ func TestCreateDefaultConfig(t *testing.T) {
 func TestCreateInstanceViaFactory(t *testing.T) {
 	cfg := createDefaultConfig()
 
-	// Default config doesn't have default endpoint so creating from it should
-	// fail.
-	ze, err := createTracesExporter(context.Background(), exportertest.NewNopCreateSettings(), cfg)
-	assert.Error(t, err)
-	assert.Nil(t, ze)
-
 	// URL doesn't have a default value so set it directly.
 	zeCfg := cfg.(*Config)
 	zeCfg.Endpoint = "http://some.location.org:9411/api/v2/spans"
-	ze, err = createTracesExporter(context.Background(), exportertest.NewNopCreateSettings(), cfg)
+	ze, err := createTracesExporter(context.Background(), exportertest.NewNopCreateSettings(), cfg)
 	assert.NoError(t, err)
 	assert.NotNil(t, ze)
 }

exporter/zipkinexporter/testdata/config.yaml

@@ -4,6 +4,8 @@ zipkin/2:
   endpoint: "https://somedest:1234/api/v2/spans"
   format: proto
   default_service_name: test_name
+  idle_conn_timeout: 5s
+  max_idle_conns: 50
   sending_queue:
     enabled: true
     num_consumers: 2