feat(otlp): support vsock gRPC endpoints

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [OTLP/gRPC] Support VSOCK endpoints on Linux
+  [#4706](https://github.com/open-telemetry/opentelemetry-cpp/issues/4706)
+
 ## [1.30.0] 2026-10-22
 
 This release contains:

exporters/otlp/README.md

@@ -75,6 +75,11 @@ auto exporter = std::make_unique<otlp::OtlpFileExporter>(options);
 |`metadata`                        |`OTEL_EXPORTER_OTLP_HEADERS`                  |                       | Custom metadata for GRPC             |
 |                                  |`OTEL_EXPORTER_OTLP_TRACES_HEADERS`           |                       |                                      |
 
+On Linux, the OTLP gRPC exporter supports VSOCK endpoints with gRPC 1.57.0 or
+later. Set `vsock://<cid>:<port>` as the endpoint; the exporter converts it
+to the `vsock:<cid>:<port>` target format expected by gRPC. A raw
+`vsock:<cid>:<port>` target is also accepted.
+
 ### Configuration options ( OTLP HTTP Exporter )
 
 | Option             | Env Variable                       | Default                         | Description                                                       |

exporters/otlp/src/otlp_grpc_client.cc

@@ -310,6 +310,12 @@ OtlpGrpcClient::~OtlpGrpcClient()
 
 std::string OtlpGrpcClient::GetGrpcTarget(const std::string &endpoint)
 {
+  // A raw VSOCK target is already in the format expected by gRPC.
+  if (endpoint.rfind("vsock:", 0) == 0 && endpoint.rfind("vsock://", 0) != 0)
+  {
+    return endpoint;
+  }
+
   //
   // Scheme is allowed in OTLP endpoint definition, but is not allowed for creating gRPC
   // channel. Passing URI with scheme to grpc::CreateChannel could resolve the endpoint to some
@@ -327,6 +333,10 @@ std::string OtlpGrpcClient::GetGrpcTarget(const std::string &endpoint)
   {
     grpc_target = "unix:" + url.path_;
   }
+  else if (url.scheme_ == "vsock")
+  {
+    grpc_target = "vsock:" + url.host_ + ":" + std::to_string(static_cast<int>(url.port_));
+  }
   else
   {
     grpc_target = url.host_ + ":" + std::to_string(static_cast<int>(url.port_));

exporters/otlp/test/otlp_grpc_target_test.cc

@@ -68,6 +68,12 @@ TEST(OtlpGrpcClientEndpointTest, GrpcClientTest)
   EXPECT_EQ(target3, "localhost:4317");
 }
 
+TEST(OtlpGrpcClientEndpointTest, VsockEndpoints)
+{
+  EXPECT_EQ(OtlpGrpcClient::GetGrpcTarget("vsock:3:1234"), "vsock:3:1234");
+  EXPECT_EQ(OtlpGrpcClient::GetGrpcTarget("vsock://3:1234"), "vsock:3:1234");
+}
+
 TEST_F(OtlpGrpcClientTestPeer, ChannelArgumentsOptionTest)
 {
   OtlpGrpcClientOptions options;