[chore] Replace extensionauth.Client mentions with protocol-specific mentions (open-telemetry#38601)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

<!-- Issue number (e.g. open-telemetry#1234) or full URL to issue, if applicable. -->

Follows open-telemetry#38451 and open-telemetry/opentelemetry-collector/pull/12574.

Removes explicit mentions to `extensionauth.Client` and replaces them by
`extensionauth.HTTPClient` and `extensionauth.GRPCClient`

Author: mx-psi

exporter/elasticsearchexporter/exporter_test.go

@@ -29,6 +29,7 @@ import (
 	"go.opentelemetry.io/collector/exporter/exporterbatcher"
 	"go.opentelemetry.io/collector/exporter/exportertest"
 	"go.opentelemetry.io/collector/exporter/xexporter"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/plog"
@@ -41,13 +42,6 @@ import (
 	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/elasticsearchexporter/internal/metadata"
 )
 
-func build[T any, O any](t *testing.T, f func(...O) (T, error), opts ...O) T {
-	t.Helper()
-	v, err := f(opts...)
-	require.NoError(t, err)
-	return v
-}
-
 func TestExporterLogs(t *testing.T) {
 	t.Run("publish with success", func(t *testing.T) {
 		rec := newBulkRecorder()
@@ -2173,17 +2167,13 @@ func TestExporterAuth(t *testing.T) {
 	})
 	err := exporter.Start(context.Background(), &mockHost{
 		extensions: map[component.ID]component.Component{
-			testauthID: build(t, extensionauth.NewClient,
-				extensionauth.WithClientRoundTripper(func(http.RoundTripper) (http.RoundTripper, error) {
-					return roundTripperFunc(func(*http.Request) (*http.Response, error) {
-						select {
-						case done <- struct{}{}:
-						default:
-						}
-						return nil, errors.New("nope")
-					}), nil
-				}),
-			),
+			testauthID: newMockAuthClient(func(*http.Request) (*http.Response, error) {
+				select {
+				case done <- struct{}{}:
+				default:
+				}
+				return nil, errors.New("nope")
+			}),
 		},
 	})
 	require.NoError(t, err)
@@ -2211,14 +2201,10 @@ func TestExporterBatcher(t *testing.T) {
 	})
 	err := exporter.Start(context.Background(), &mockHost{
 		extensions: map[component.ID]component.Component{
-			testauthID: build(t, extensionauth.NewClient,
-				extensionauth.WithClientRoundTripper(func(http.RoundTripper) (http.RoundTripper, error) {
-					return roundTripperFunc(func(req *http.Request) (*http.Response, error) {
-						requests = append(requests, req)
-						return nil, errors.New("nope")
-					}), nil
-				}),
-			),
+			testauthID: newMockAuthClient(func(req *http.Request) (*http.Response, error) {
+				requests = append(requests, req)
+				return nil, errors.New("nope")
+			}),
 		},
 	})
 	require.NoError(t, err)
@@ -2396,6 +2382,23 @@ func (f roundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
 	return f(r)
 }
 
+var (
+	_ extension.Extension      = (*mockAuthClient)(nil)
+	_ extensionauth.HTTPClient = (*mockAuthClient)(nil)
+)
+
+type mockAuthClient struct {
+	component.StartFunc
+	component.ShutdownFunc
+	extensionauth.ClientRoundTripperFunc
+}
+
+func newMockAuthClient(f func(*http.Request) (*http.Response, error)) *mockAuthClient {
+	return &mockAuthClient{ClientRoundTripperFunc: func(http.RoundTripper) (http.RoundTripper, error) {
+		return roundTripperFunc(f), nil
+	}}
+}
+
 func actionJSONToIndex(t *testing.T, actionJSON json.RawMessage) string {
 	t.Helper()
 	return actionGetValue(t, actionJSON, "_index")

exporter/elasticsearchexporter/go.mod

@@ -27,6 +27,7 @@ require (
 	go.opentelemetry.io/collector/exporter/exporterhelper/xexporterhelper v0.121.1-0.20250313100724-0885401136ff
 	go.opentelemetry.io/collector/exporter/exportertest v0.121.1-0.20250313100724-0885401136ff
 	go.opentelemetry.io/collector/exporter/xexporter v0.121.1-0.20250313100724-0885401136ff
+	go.opentelemetry.io/collector/extension v1.27.1-0.20250313100724-0885401136ff
 	go.opentelemetry.io/collector/extension/extensionauth v0.121.1-0.20250313100724-0885401136ff
 	go.opentelemetry.io/collector/pdata v1.27.1-0.20250313100724-0885401136ff
 	go.opentelemetry.io/collector/pdata/pprofile v0.121.1-0.20250313100724-0885401136ff
@@ -83,7 +84,6 @@ require (
 	go.opentelemetry.io/collector/consumer/consumererror/xconsumererror v0.121.1-0.20250313100724-0885401136ff // indirect
 	go.opentelemetry.io/collector/consumer/consumertest v0.121.1-0.20250313100724-0885401136ff // indirect
 	go.opentelemetry.io/collector/consumer/xconsumer v0.121.1-0.20250313100724-0885401136ff // indirect
-	go.opentelemetry.io/collector/extension v1.27.1-0.20250313100724-0885401136ff // indirect
 	go.opentelemetry.io/collector/extension/xextension v0.121.1-0.20250313100724-0885401136ff // indirect
 	go.opentelemetry.io/collector/featuregate v1.27.1-0.20250313100724-0885401136ff // indirect
 	go.opentelemetry.io/collector/pipeline v0.121.1-0.20250313100724-0885401136ff // indirect

exporter/otelarrowexporter/otelarrow.go

@@ -140,7 +140,7 @@ func (e *baseExporter) start(ctx context.Context, host component.Host) (err erro
 		var perRPCCreds credentials.PerRPCCredentials
 		if e.config.ClientConfig.Auth != nil {
 			// Get the auth extension, we'll use it to enrich the request context.
-			authClient, err := e.config.ClientConfig.Auth.GetClientAuthenticator(ctx, host.GetExtensions())
+			authClient, err := e.config.ClientConfig.Auth.GetGRPCClientAuthenticator(ctx, host.GetExtensions())
 			if err != nil {
 				return err
 			}

exporter/otelarrowexporter/otelarrow_test.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"net/http"
 	"path/filepath"
 	"runtime"
 	"sync"
@@ -264,13 +263,15 @@ func (h *hostWithExtensions) GetExtensions() map[component.ID]component.Componen
 	return h.exts
 }
 
+var _ extensionauth.GRPCClient = (*testAuthExtension)(nil)
+
 type testAuthExtension struct {
 	extension.Extension
 
 	prc credentials.PerRPCCredentials
 }
 
-func newTestAuthExtension(t *testing.T, mdf func(ctx context.Context) map[string]string) extensionauth.Client {
+func newTestAuthExtension(t *testing.T, mdf func(ctx context.Context) map[string]string) extension.Extension {
 	ctrl := gomock.NewController(t)
 	prc := grpcmock.NewMockPerRPCCredentials(ctrl)
 	prc.EXPECT().RequireTransportSecurity().AnyTimes().Return(false)
@@ -284,10 +285,6 @@ func newTestAuthExtension(t *testing.T, mdf func(ctx context.Context) map[string
 	}
 }
 
-func (a *testAuthExtension) RoundTripper(_ http.RoundTripper) (http.RoundTripper, error) {
-	return nil, fmt.Errorf("unused")
-}
-
 func (a *testAuthExtension) PerRPCCredentials() (credentials.PerRPCCredentials, error) {
 	return a.prc, nil
 }

extension/asapauthextension/extension.go

@@ -11,11 +11,16 @@ import (
 	"bitbucket.org/atlassian/go-asap/v2"
 	"github.com/SermoDigital/jose/crypto"
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"google.golang.org/grpc/credentials"
 )
 
-var _ extensionauth.Client = (*asapAuthExtension)(nil)
+var (
+	_ extension.Extension      = (*asapAuthExtension)(nil)
+	_ extensionauth.HTTPClient = (*asapAuthExtension)(nil)
+	_ extensionauth.GRPCClient = (*asapAuthExtension)(nil)
+)
 
 type asapAuthExtension struct {
 	component.StartFunc
@@ -25,17 +30,17 @@ type asapAuthExtension struct {
 	privateKey  any
 }
 
-// PerRPCCredentials returns extensionauth.Client.
+// PerRPCCredentials returns extensionauth.GRPCClient.
 func (e *asapAuthExtension) PerRPCCredentials() (credentials.PerRPCCredentials, error) {
 	return &perRPCAuth{provisioner: e.provisioner, privateKey: e.privateKey}, nil
 }
 
-// RoundTripper implements extensionauth.Client.
+// RoundTripper implements extensionauth.HTTPClient.
 func (e *asapAuthExtension) RoundTripper(base http.RoundTripper) (http.RoundTripper, error) {
 	return asap.NewTransportDecorator(e.provisioner, e.privateKey)(base), nil
 }
 
-func createASAPClientAuthenticator(cfg *Config) (extensionauth.Client, error) {
+func createASAPClientAuthenticator(cfg *Config) (*asapAuthExtension, error) {
 	pk, err := asap.NewPrivateKey([]byte(cfg.PrivateKey))
 	if err != nil {
 		return nil, err

extension/basicauthextension/extension.go

@@ -16,6 +16,7 @@ import (
 	"github.com/tg123/go-htpasswd"
 	"go.opentelemetry.io/collector/client"
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	creds "google.golang.org/grpc/credentials"
 )
@@ -27,7 +28,7 @@ var (
 	errInvalidFormat       = errors.New("invalid authorization format")
 )
 
-func newClientAuthExtension(cfg *Config) extensionauth.Client {
+func newClientAuthExtension(cfg *Config) *basicAuthClient {
 	return &basicAuthClient{clientAuth: cfg.ClientAuth}
 }
 
@@ -201,7 +202,11 @@ func (b *basicAuthRoundTripper) RoundTrip(request *http.Request) (*http.Response
 	return b.base.RoundTrip(newRequest)
 }
 
-var _ extensionauth.Client = (*basicAuthClient)(nil)
+var (
+	_ extension.Extension      = (*basicAuthClient)(nil)
+	_ extensionauth.HTTPClient = (*basicAuthClient)(nil)
+	_ extensionauth.GRPCClient = (*basicAuthClient)(nil)
+)
 
 type basicAuthClient struct {
 	component.StartFunc

extension/bearertokenauthextension/bearertokenauth.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/fsnotify/fsnotify"
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"go.uber.org/zap"
 	"google.golang.org/grpc/credentials"
@@ -38,11 +39,13 @@ func (c *PerRPCAuth) RequireTransportSecurity() bool {
 }
 
 var (
-	_ extensionauth.Server = (*BearerTokenAuth)(nil)
-	_ extensionauth.Client = (*BearerTokenAuth)(nil)
+	_ extension.Extension      = (*BearerTokenAuth)(nil)
+	_ extensionauth.Server     = (*BearerTokenAuth)(nil)
+	_ extensionauth.HTTPClient = (*BearerTokenAuth)(nil)
+	_ extensionauth.GRPCClient = (*BearerTokenAuth)(nil)
 )
 
-// BearerTokenAuth is an implementation of extensionauth.Client. It embeds a static authorization "bearer" token in every rpc call.
+// BearerTokenAuth is an implementation of extensionauth interfaces. It embeds a static authorization "bearer" token in every rpc call.
 type BearerTokenAuth struct {
 	scheme                    string
 	authorizationValuesAtomic atomic.Value
@@ -53,8 +56,6 @@ type BearerTokenAuth struct {
 	logger   *zap.Logger
 }
 
-var _ extensionauth.Client = (*BearerTokenAuth)(nil)
-
 func newBearerTokenAuth(cfg *Config, logger *zap.Logger) *BearerTokenAuth {
 	if cfg.Filename != "" && (cfg.BearerToken != "" || len(cfg.Tokens) > 0) {
 		logger.Warn("a filename is specified. Configured token(s) is ignored!")

extension/headerssetterextension/extension.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"go.uber.org/zap"
 	"google.golang.org/grpc/credentials"
@@ -23,7 +24,11 @@ type Header struct {
 	source source.Source
 }
 
-var _ extensionauth.Client = (*headerSetterExtension)(nil)
+var (
+	_ extension.Extension      = (*headerSetterExtension)(nil)
+	_ extensionauth.HTTPClient = (*headerSetterExtension)(nil)
+	_ extensionauth.GRPCClient = (*headerSetterExtension)(nil)
+)
 
 type headerSetterExtension struct {
 	component.StartFunc
@@ -32,20 +37,20 @@ type headerSetterExtension struct {
 	headers []Header
 }
 
-// PerRPCCredentials implements extensionauth.Client.
+// PerRPCCredentials implements extensionauth.GRPCClient.
 func (h *headerSetterExtension) PerRPCCredentials() (credentials.PerRPCCredentials, error) {
 	return &headersPerRPC{headers: h.headers}, nil
 }
 
-// RoundTripper implements extensionauth.Client.
+// RoundTripper implements extensionauth.HTTPClient.
 func (h *headerSetterExtension) RoundTripper(base http.RoundTripper) (http.RoundTripper, error) {
 	return &headersRoundTripper{
 		base:    base,
 		headers: h.headers,
 	}, nil
 }
 
-func newHeadersSetterExtension(cfg *Config, logger *zap.Logger) (extensionauth.Client, error) {
+func newHeadersSetterExtension(cfg *Config, logger *zap.Logger) (*headerSetterExtension, error) {
 	if cfg == nil {
 		return nil, errors.New("extension configuration is not provided")
 	}

extension/oauth2clientauthextension/extension.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"go.uber.org/multierr"
 	"go.uber.org/zap"
@@ -18,7 +19,11 @@ import (
 	grpcOAuth "google.golang.org/grpc/credentials/oauth"
 )
 
-var _ extensionauth.Client = (*clientAuthenticator)(nil)
+var (
+	_ extension.Extension      = (*clientAuthenticator)(nil)
+	_ extensionauth.HTTPClient = (*clientAuthenticator)(nil)
+	_ extensionauth.GRPCClient = (*clientAuthenticator)(nil)
+)
 
 // clientAuthenticator provides implementation for providing client authentication using OAuth2 client credentials
 // workflow for both gRPC and HTTP clients.

extension/opampextension/auth.go

@@ -46,9 +46,9 @@ func makeHeadersFunc(logger *zap.Logger, serverCfg *OpAMPServer, host component.
 		return nil, fmt.Errorf("could not find auth extension %q", extID)
 	}
 
-	authExt, ok := ext.(extensionauth.Client)
+	authExt, ok := ext.(extensionauth.HTTPClient)
 	if !ok {
-		return nil, fmt.Errorf("auth extension %q is not an extensionauth.Client", extID)
+		return nil, fmt.Errorf("auth extension %q is not an extensionauth.HTTPClient", extID)
 	}
 
 	hcrt := &headerCaptureRoundTripper{}