apikeyauthextension: propagate status code in errs (#650)

Updates the extension to return a `status.Error` type (which wraps the
`status.Status` type) instead of a plain `error` type. This allows
propagating the status code and message from the extension to the
collector.

This is similar to what the upstream OTLP receiver does:

https://github.com/open-telemetry/opentelemetry-collector/blob/v0.129.0/receiver/otlpreceiver/otlphttp.go#L183-L192

---------

Signed-off-by: Marc Lopez Rubio <[email protected]>

Author: marclop

extension/apikeyauthextension/authenticator.go

@@ -32,6 +32,8 @@ import (
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/extension/extensionauth"
 	"golang.org/x/crypto/pbkdf2"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 
 	"github.com/elastic/go-elasticsearch/v8"
 	"github.com/elastic/go-elasticsearch/v8/typedapi/security/hasprivileges"
@@ -222,10 +224,14 @@ func (a *authenticator) getCacheKey(id string, headers map[string][]string) (str
 
 // Authenticate validates an ApiKey scheme Authorization header,
 // passing it to Elasticsearch for checking privileges.
+//
+// Callers can use status.FromError(err) to get the status code
+// and message from the returned error. If no status.Status is returned,
+// the error should be considered an internal error.
 func (a *authenticator) Authenticate(ctx context.Context, headers map[string][]string) (context.Context, error) {
 	authHeaderValue, id, err := a.parseAuthorizationHeader(headers)
 	if err != nil {
-		return ctx, err
+		return ctx, status.Error(codes.Unauthenticated, err.Error())
 	}
 
 	cacheKey, err := a.getCacheKey(id, headers)
@@ -245,27 +251,29 @@ func (a *authenticator) Authenticate(ctx context.Context, headers map[string][]s
 			// Client has specified an API Key with a colliding ID,
 			// but whose secret component does not match the one in
 			// the cache.
-			return ctx, fmt.Errorf("API Key %q unauthorized", id)
+			return ctx, status.Errorf(codes.Unauthenticated,
+				"API Key %q unauthorized", id,
+			)
 		}
 		if cacheEntry.err != nil {
-			return ctx, cacheEntry.err
+			return ctx, status.Error(codes.Unauthenticated, cacheEntry.err.Error())
 		}
-		clientInfo := client.FromContext(ctx)
-		clientInfo.Auth = cacheEntry.data
-		return client.NewContext(ctx, clientInfo), nil
+		return newCtxWithAuthData(ctx, cacheEntry.data), nil
 	}
 
 	hasPrivileges, username, err := a.hasPrivileges(ctx, authHeaderValue)
 	if err != nil {
-		return ctx, err
+		return ctx, fmt.Errorf(
+			"error checking privileges for API Key %q: %v", id, err,
+		)
 	}
 	if !hasPrivileges {
 		cacheEntry := &cacheEntry{
 			key: derivedKey,
 			err: fmt.Errorf("API Key %q unauthorized", id),
 		}
 		a.cache.Add(cacheKey, cacheEntry)
-		return ctx, cacheEntry.err
+		return ctx, status.Error(codes.PermissionDenied, cacheEntry.err.Error())
 	}
 	cacheEntry := &cacheEntry{
 		key: derivedKey,
@@ -275,7 +283,11 @@ func (a *authenticator) Authenticate(ctx context.Context, headers map[string][]s
 		},
 	}
 	a.cache.Add(cacheKey, cacheEntry)
+	return newCtxWithAuthData(ctx, cacheEntry.data), nil
+}
+
+func newCtxWithAuthData(ctx context.Context, authData *authData) context.Context {
 	clientInfo := client.FromContext(ctx)
-	clientInfo.Auth = cacheEntry.data
-	return client.NewContext(ctx, clientInfo), nil
+	clientInfo.Auth = authData
+	return client.NewContext(ctx, clientInfo)
 }

extension/apikeyauthextension/authenticator_test.go

@@ -74,11 +74,11 @@ func TestAuthenticator(t *testing.T) {
 				},
 				Status: 400,
 			}),
-			expectedErr: `status: 400, failed: [a_type], reason: a_reason`,
+			expectedErr: `error checking privileges for API Key "id": status: 400, failed: [a_type], reason: a_reason`,
 		},
 		"missing_privileges": {
 			handler:     newCannedHasPrivilegesHandler(hasprivileges.Response{HasAllRequested: false}),
-			expectedErr: `API Key "id" unauthorized`,
+			expectedErr: `rpc error: code = PermissionDenied desc = API Key "id" unauthorized`,
 		},
 	} {
 		t.Run(name, func(t *testing.T) {
@@ -170,7 +170,7 @@ func TestAuthenticator_Caching(t *testing.T) {
 	_, err = authenticator.Authenticate(context.Background(), map[string][]string{
 		"Authorization": {"ApiKey " + base64.StdEncoding.EncodeToString([]byte("id2:secret2"))},
 	})
-	assert.EqualError(t, err, `API Key "id2" unauthorized`)
+	assert.EqualError(t, err, `rpc error: code = Unauthenticated desc = API Key "id2" unauthorized`)
 }
 
 func TestAuthenticator_CacheKeyHeaders(t *testing.T) {
@@ -259,29 +259,29 @@ func TestAuthenticator_AuthorizationHeader(t *testing.T) {
 		},
 		"missing_header": {
 			headers:     map[string][]string{},
-			expectedErr: `missing header "Authorization"`,
+			expectedErr: `rpc error: code = Unauthenticated desc = missing header "Authorization"`,
 		},
 		"invalid_scheme": {
 			headers: map[string][]string{
 				"Authorization": {
 					"Bearer " + base64.StdEncoding.EncodeToString([]byte("id:secret")),
 				},
 			},
-			expectedErr: `ApiKey prefix not found`,
+			expectedErr: `rpc error: code = Unauthenticated desc = ApiKey prefix not found`,
 		},
 		"invalid_base64": {
 			headers: map[string][]string{
 				"Authorization": {"ApiKey not_base64"},
 			},
-			expectedErr: "illegal base64 data at input byte 3",
+			expectedErr: "rpc error: code = Unauthenticated desc = illegal base64 data at input byte 3",
 		},
 		"invalid_encoded_apikey": {
 			headers: map[string][]string{
 				"Authorization": {
 					"ApiKey " + base64.StdEncoding.EncodeToString([]byte("junk")),
 				},
 			},
-			expectedErr: "invalid API Key",
+			expectedErr: "rpc error: code = Unauthenticated desc = invalid API Key",
 		},
 	} {
 		t.Run(name, func(t *testing.T) {

extension/apikeyauthextension/go.mod

@@ -17,6 +17,7 @@ require (
 	go.opentelemetry.io/collector/extension/extensiontest v0.129.0
 	go.uber.org/goleak v1.3.0
 	golang.org/x/crypto v0.39.0
+	google.golang.org/grpc v1.73.0
 )
 
 require (
@@ -67,7 +68,6 @@ require (
 	golang.org/x/sys v0.33.0 // indirect
 	golang.org/x/text v0.26.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250324211829-b45e905df463 // indirect
-	google.golang.org/grpc v1.73.0 // indirect
 	google.golang.org/protobuf v1.36.6 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	sigs.k8s.io/yaml v1.4.0 // indirect