daemon-grpc: update Capabilities RPC to return supported features p…

…er module

It's important to know which features are enabled or disabled, as
this determines which parts of the YANG module are implemented.

gNMI's `Capabilities` RPC doesn't provide this information, since
OpenConfig modules typically don't use "feature" and "if-feature"
statements, unlike IETF models.

Signed-off-by: Renato Westphal <[email protected]>

holo-daemon/src/northbound/client/grpc.rs

@@ -9,7 +9,7 @@ use std::time::SystemTime;
 
 use futures::Stream;
 use holo_utils::Sender;
-use holo_yang::YANG_CTX;
+use holo_yang::{YANG_CTX, YANG_FEATURES};
 use tokio::sync::oneshot;
 use tonic::transport::{Server, ServerTlsConfig};
 use tonic::{Request, Response, Status};
@@ -63,6 +63,15 @@ impl proto::Northbound for NorthboundService {
                     .unwrap_or_default()
                     .to_owned(),
                 revision: module.revision().unwrap_or_default().to_owned(),
+                supported_features: YANG_FEATURES
+                    .get(&module.name())
+                    .map(|features| {
+                        features
+                            .iter()
+                            .map(|feature| (*feature).to_owned())
+                            .collect()
+                    })
+                    .unwrap_or_default(),
             })
             .collect();
 

proto/holo.proto

@@ -231,6 +231,9 @@ message ModuleData {
 
   // Latest revision of the module;
   string revision = 3;
+
+  // Supported features.
+  repeated string supported_features = 4;
 }
 
 // Supported encodings for YANG instance data.