re-export cherry-picked tonic types

Author: MathieuTricoire

opentelemetry-otlp/allowed-external-types.toml

@@ -13,10 +13,12 @@ allowed_external_types = [
     # prost is a pre 1.0 crate
     "prost::error::EncodeError",
     # tonic is a pre 1.0 crate
-    "tonic",
     "tonic::status::Code",
     "tonic::status::Status",
     "tonic::metadata::map::MetadataMap",
+    "tonic::transport::channel::tls::ClientTlsConfig",
+    "tonic::transport::tls::Certificate",
+    "tonic::transport::tls::Identity",
     "tonic::transport::channel::Channel",
     "tonic::transport::error::Error",
     "tonic::service::interceptor::Interceptor",

opentelemetry-otlp/src/lib.rs

@@ -452,5 +452,15 @@ pub enum Protocol {
 pub struct NoExporterConfig(());
 
 #[cfg(feature = "grpc-tonic")]
-#[doc(no_inline)]
-pub use tonic;
+pub mod tonic_types {
+    pub mod metadata {
+        #[doc(no_inline)]
+        pub use tonic::metadata::MetadataMap;
+    }
+
+    #[cfg(feature = "tls")]
+    pub mod transport {
+        #[doc(no_inline)]
+        pub use tonic::transport::{Certificate, ClientTlsConfig, Identity};
+    }
+}