Fixed nodes usage responses.

Signed-off-by: dblock <dblock@amazon.com>

spec/schemas/nodes.usage.yaml

@@ -10,6 +10,7 @@ components:
       type: string
       enum:
         - _all
+        - aggregations
         - rest_actions
     ResponseBase:
       allOf:
@@ -41,7 +42,5 @@ components:
           additionalProperties:
             type: object
       required:
-        - aggregations
-        - rest_actions
         - since
         - timestamp

tests/default/nodes/stats.yaml

@@ -179,3 +179,14 @@ chapters:
         - search
     response:
       status: 200
+  - synopsis: Get statistics for search (`node_id`).
+    path: /_nodes/{node_id}/stats/{metric}/{index_metric}
+    method: GET
+    parameters:
+      node_id: _all
+      metric:
+        - indices
+      index_metric:
+        - search
+    response:
+      status: 200

tests/default/nodes/usage.yaml

@@ -0,0 +1,60 @@
+$schema: ../../../json_schemas/test_story.schema.yaml
+
+description: Test nodes usage.
+chapters:
+  - synopsis: Get usage for all nodes.
+    path: /_nodes/usage
+    method: GET
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes for all metrics.
+    path: /_nodes/usage/{metric}
+    method: GET
+    parameters:
+      metric:
+        - _all
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes for the `rest_actions` metric.
+    path: /_nodes/usage/{metric}
+    method: GET
+    parameters:
+      metric:
+        - rest_actions
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes for the `aggregations` metric.
+    path: /_nodes/usage/{metric}
+    method: GET
+    parameters:
+      metric:
+        - aggregations
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes (`node_id`).
+    path: /_nodes/{node_id}/usage
+    method: GET
+    parameters:
+      node_id: _all
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes for all metrics (`node_id`).
+    path: /_nodes/{node_id}/usage/{metric}
+    method: GET
+    parameters:
+      node_id: _all
+      metric:
+        - _all
+    response:
+      status: 200
+  - synopsis: Get usage for all nodes and all metrics.
+    warnings:
+      multiple-paths-detected: false
+    path: /_nodes/{node_id}/{metric}
+    method: GET
+    parameters:
+      node_id: _all
+      metric:
+        - _all
+    response:
+      status: 200