Fix metrics handler signature (#463)

* concept

* remove from ServeOpts and do breaking change

* use correct cast

* remove from manager

* add protobuf converters

backend/convert_from_protobuf.go

@@ -193,6 +193,13 @@ func (f ConvertFromProtobuf) CheckHealthResponse(protoResp *pluginv2.CheckHealth
 	}
 }
 
+// CollectMetricsRequest converts protobuf version of a CollectMetricsRequest to the SDK version.
+func (f ConvertFromProtobuf) CollectMetricsRequest(protoReq *pluginv2.CollectMetricsRequest) *CollectMetricsRequest {
+	return &CollectMetricsRequest{
+		PluginContext: f.PluginContext(protoReq.PluginContext),
+	}
+}
+
 // CollectMetricsResponse converts protobuf version of a CollectMetricsResponse to the SDK version.
 func (f ConvertFromProtobuf) CollectMetricsResponse(protoResp *pluginv2.CollectMetricsResponse) *CollectMetricsResult {
 	var prometheusMetrics []byte

backend/convert_to_protobuf.go

@@ -250,3 +250,19 @@ func (t ConvertToProtobuf) StreamPacket(p *StreamPacket) *pluginv2.StreamPacket
 	}
 	return protoReq
 }
+
+// CollectMetricsRequest converts the SDK version of a CollectMetricsRequest to the protobuf version.
+func (t ConvertToProtobuf) CollectMetricsRequest(req *CollectMetricsRequest) *pluginv2.CollectMetricsRequest {
+	return &pluginv2.CollectMetricsRequest{
+		PluginContext: t.PluginContext(req.PluginContext),
+	}
+}
+
+// CollectMetricsResult converts the SDK version of a CollectMetricsResult to the protobuf version.
+func (t ConvertToProtobuf) CollectMetricsResult(res *CollectMetricsResult) *pluginv2.CollectMetricsResponse {
+	return &pluginv2.CollectMetricsResponse{
+		Metrics: &pluginv2.CollectMetricsResponse_Payload{
+			Prometheus: res.PrometheusMetrics,
+		},
+	}
+}

backend/diagnostics.go

@@ -65,18 +65,23 @@ type CheckHealthResult struct {
 
 // CollectMetricsHandler handles metric collection.
 type CollectMetricsHandler interface {
-	CollectMetrics(ctx context.Context) (*CollectMetricsResult, error)
+	CollectMetrics(ctx context.Context, req *CollectMetricsRequest) (*CollectMetricsResult, error)
 }
 
 // CollectMetricsHandlerFunc is an adapter to allow the use of
 // ordinary functions as backend.CollectMetricsHandler. If f is a function
 // with the appropriate signature, CollectMetricsHandlerFunc(f) is a
 // Handler that calls f.
-type CollectMetricsHandlerFunc func(ctx context.Context) (*CollectMetricsResult, error)
+type CollectMetricsHandlerFunc func(ctx context.Context, req *CollectMetricsRequest) (*CollectMetricsResult, error)
 
 // CollectMetrics calls fn(ctx, req).
-func (fn CollectMetricsHandlerFunc) CollectMetrics(ctx context.Context) (*CollectMetricsResult, error) {
-	return fn(ctx)
+func (fn CollectMetricsHandlerFunc) CollectMetrics(ctx context.Context, req *CollectMetricsRequest) (*CollectMetricsResult, error) {
+	return fn(ctx, req)
+}
+
+// CollectMetricsRequest contains the metrics request
+type CollectMetricsRequest struct {
+	PluginContext PluginContext
 }
 
 // CollectMetricsResult collect metrics result.