add selector for router service in custom telemetry (#5392)

Signed-off-by: Benjamin Coenen <5719034+bnjjj@users.noreply.github.com>

.changesets/feat_bnjjj_add_operation_name_router_selector.md

@@ -0,0 +1,18 @@
+### Add selector for router service in custom telemetry ([PR #5392](https://github.com/apollographql/router/pull/5392))
+
+Instead of having to access to the operation_name using the response_context at the router service, we now provide a selector for operation name at the router service in instrumentations.
+
+example:
+
+```yaml
+telemetry:
+  instrumentation:
+    instruments:
+      router:
+        http.server.request.duration:
+          attributes:
+            graphql.operation.name:
+              operation_name: string
+```
+
+By [@bnjjj](https://github.com/bnjjj) in https://github.com/apollographql/router/pull/5392

apollo-router/src/configuration/snapshots/apollo_router__configuration__tests__schema_generation.snap

@@ -5097,6 +5097,25 @@ expression: "&schema"
           ],
           "type": "object"
         },
+        {
+          "additionalProperties": false,
+          "description": "The operation name from the query.",
+          "properties": {
+            "default": {
+              "description": "Optional default value.",
+              "nullable": true,
+              "type": "string"
+            },
+            "operation_name": {
+              "$ref": "#/definitions/OperationName",
+              "description": "#/definitions/OperationName"
+            }
+          },
+          "required": [
+            "operation_name"
+          ],
+          "type": "object"
+        },
         {
           "additionalProperties": false,
           "description": "A value from baggage.",

apollo-router/src/plugins/telemetry/config_new/fixtures/router/http.server.request.duration_with_custom_attributes/metrics.snap

@@ -12,6 +12,8 @@ info:
             attributes:
               my_attribute:
                 request_method: true
+              graphql.operation.name:
+                operation_name: string
 ---
 - name: http.server.request.duration
   description: Duration of HTTP server requests.
@@ -20,6 +22,7 @@ info:
     datapoints:
       - sum: 0.1
         attributes:
+          graphql.operation.name: TestQuery
           http.request.method: GET
           http.response.status_code: 200
           my_attribute: GET

apollo-router/src/plugins/telemetry/config_new/fixtures/router/http.server.request.duration_with_custom_attributes/router.yaml

@@ -6,4 +6,6 @@ telemetry:
         http.server.request.duration:
           attributes:
             my_attribute:
-              request_method: true
+              request_method: true
+            graphql.operation.name:
+              operation_name: string

apollo-router/src/plugins/telemetry/config_new/fixtures/router/http.server.request.duration_with_custom_attributes/test.yaml

@@ -5,6 +5,9 @@ events:
         method: GET
         body: |
           hello
+    - context:
+        map:
+          operation_name: TestQuery
     - router_response:
         body: |
           hello

apollo-router/src/plugins/telemetry/config_new/selectors.rs

@@ -140,6 +140,17 @@ pub(crate) enum RouterSelector {
         /// Optional default value.
         default: Option<AttributeValue>,
     },
+    /// The operation name from the query.
+    OperationName {
+        /// The operation name from the query.
+        operation_name: OperationName,
+        #[serde(skip)]
+        #[allow(dead_code)]
+        /// Optional redaction pattern.
+        redact: Option<String>,
+        /// Optional default value.
+        default: Option<String>,
+    },
     /// A value from baggage.
     Baggage {
         /// The name of the baggage item.
@@ -617,6 +628,23 @@ impl Selector for RouterSelector {
                 .as_ref()
                 .and_then(|v| v.maybe_to_otel_value())
                 .or_else(|| default.maybe_to_otel_value()),
+            RouterSelector::OperationName {
+                operation_name,
+                default,
+                ..
+            } => {
+                let op_name = response.context.get(OPERATION_NAME).ok().flatten();
+                match operation_name {
+                    OperationName::String => op_name.or_else(|| default.clone()),
+                    OperationName::Hash => op_name.or_else(|| default.clone()).map(|op_name| {
+                        let mut hasher = sha2::Sha256::new();
+                        hasher.update(op_name.as_bytes());
+                        let result = hasher.finalize();
+                        hex::encode(result)
+                    }),
+                }
+                .map(opentelemetry::Value::from)
+            }
             RouterSelector::Baggage {
                 baggage, default, ..
             } => get_baggage(baggage).or_else(|| default.maybe_to_otel_value()),
@@ -657,6 +685,23 @@ impl Selector for RouterSelector {
                 .as_ref()
                 .and_then(|v| v.maybe_to_otel_value())
                 .or_else(|| default.maybe_to_otel_value()),
+            RouterSelector::OperationName {
+                operation_name,
+                default,
+                ..
+            } => {
+                let op_name = ctx.get(OPERATION_NAME).ok().flatten();
+                match operation_name {
+                    OperationName::String => op_name.or_else(|| default.clone()),
+                    OperationName::Hash => op_name.or_else(|| default.clone()).map(|op_name| {
+                        let mut hasher = sha2::Sha256::new();
+                        hasher.update(op_name.as_bytes());
+                        let result = hasher.finalize();
+                        hex::encode(result)
+                    }),
+                }
+                .map(opentelemetry::Value::from)
+            }
             _ => None,
         }
     }
@@ -2013,6 +2058,39 @@ mod test {
         );
     }
 
+    #[test]
+    fn router_operation_name_string() {
+        let selector = RouterSelector::OperationName {
+            operation_name: OperationName::String,
+            redact: None,
+            default: Some("defaulted".to_string()),
+        };
+        let context = crate::context::Context::new();
+        assert_eq!(
+            selector.on_response(
+                &crate::services::RouterResponse::fake_builder()
+                    .context(context.clone())
+                    .build()
+                    .unwrap(),
+            ),
+            Some("defaulted".into())
+        );
+        let _ = context.insert(OPERATION_NAME, "topProducts".to_string());
+        assert_eq!(
+            selector.on_response(
+                &crate::services::RouterResponse::fake_builder()
+                    .context(context.clone())
+                    .build()
+                    .unwrap(),
+            ),
+            Some("topProducts".into())
+        );
+        assert_eq!(
+            selector.on_error(&BoxError::from(String::from("my error")), &context),
+            Some("topProducts".into())
+        );
+    }
+
     #[test]
     fn supergraph_env() {
         let selector = SupergraphSelector::Env {

docs/source/configuration/telemetry/instrumentation/selectors.mdx

@@ -32,7 +32,8 @@ The router service is the initial entrypoint for all requests. It is HTTP centri
 
 | Selector           | Defaultable | Values                                    | Description                          |
 |--------------------|-------------|-------------------------------------------|--------------------------------------|
-| `trace_id`         | Yes         | `open_telemetry`\|`datadog`              | The trace ID                         |
+| `trace_id`         | Yes         | `open_telemetry`\|`datadog`               | The trace ID                         |
+| `operation_name`   | Yes         | `string`|`hash`                           | The operation name from the query    |
 | `studio_operation_id` | Yes      | `true`|`false`                            | The Apollo Studio operation id       |
 | `request_header`   | Yes         |                                           | The name of the request header       |
 | `response_header`  | Yes         |                                           | The name of a response header        |