set response index and meta information

add tests for edge cases

nomad/resources_endpoint.go

@@ -106,20 +106,32 @@ func (r *Resources) List(args *structs.ResourcesRequest,
 				}
 			}
 
-			// return jobs matching given prefix
+			// Return jobs matching given prefix
 			for k, v := range iters {
 				res, isTrunc := getMatches(v)
 				reply.Matches[k] = res
 				reply.Truncations[k] = isTrunc
 			}
 
-			// Use the last index that affected the table
+			// Set the index of the context if it is specified. Otherwise, set the
-			index, err := state.Index(args.Context)
+			// index of the first non-empty match set.
+			var index uint64
+			var err error
+			if args.Context != "" {
+				index, err = state.Index(args.Context)
+			} else {
+				for k, v := range reply.Matches {
+					if len(v) != 0 {
+						index, err = state.Index(k)
+					}
+				}
+			}
 			if err != nil {
 				return err
 			}
 			reply.Index = index
 
+			r.srv.setQueryMeta(&reply.QueryMeta)
 			return nil
 		}}
 	return r.srv.blockingRPC(&opts)

nomad/resources_endpoint_test.go

@@ -49,6 +49,7 @@ func TestResourcesEndpoint_List(t *testing.T) {
 
 	assert.Equal(t, 1, len(resp.Matches["job"]))
 	assert.Equal(t, jobID, resp.Matches["job"][0])
+	assert.NotEqual(t, 0, resp.Index)
 }
 
 // truncate should limit results to 20
@@ -80,6 +81,7 @@ func TestResourcesEndpoint_List_Truncate(t *testing.T) {
 
 	assert.Equal(t, 20, len(resp.Matches["job"]))
 	assert.Equal(t, resp.Truncations["job"], true)
+	assert.NotEqual(t, 0, resp.Index)
 }
 
 func TestResourcesEndpoint_List_Evals(t *testing.T) {
@@ -110,6 +112,8 @@ func TestResourcesEndpoint_List_Evals(t *testing.T) {
 	assert.Equal(t, 1, len(resp.Matches["eval"]))
 	assert.Equal(t, eval1.ID, resp.Matches["eval"][0])
 	assert.Equal(t, resp.Truncations["job"], false)
+
+	assert.NotEqual(t, 0, resp.Index)
 }
 
 func TestResourcesEndpoint_List_Allocation(t *testing.T) {
@@ -148,6 +152,8 @@ func TestResourcesEndpoint_List_Allocation(t *testing.T) {
 	assert.Equal(t, 1, len(resp.Matches["alloc"]))
 	assert.Equal(t, alloc.ID, resp.Matches["alloc"][0])
 	assert.Equal(t, resp.Truncations["alloc"], false)
+
+	assert.NotEqual(t, 0, resp.Index)
 }
 
 func TestResourcesEndpoint_List_Node(t *testing.T) {
@@ -202,6 +208,8 @@ func TestResourcesEndpoint_List_InvalidContext(t *testing.T) {
 	var resp structs.ResourcesResponse
 	err := msgpackrpc.CallWithCodec(codec, "Resources.List", req, &resp)
 	assert.Equal(t, err.Error(), "invalid context")
+
+	assert.NotEqual(t, 0, resp.Index)
 }
 
 func TestResourcesEndpoint_List_NoContext(t *testing.T) {
@@ -244,4 +252,64 @@ func TestResourcesEndpoint_List_NoContext(t *testing.T) {
 
 	assert.Equal(t, node.ID, resp.Matches["node"][0])
 	assert.Equal(t, eval1.ID, resp.Matches["eval"][0])
+
+	assert.NotEqual(t, 0, resp.Index)
+}
+
+// Tests that the top 20 matches are returned when no prefix is set
+func TestResourcesEndpoint_List_NoPrefix(t *testing.T) {
+	prefix := "aaaaaaaa-e8f7-fd38-c855-ab94ceb8970"
+
+	t.Parallel()
+	s := testServer(t, func(c *Config) {
+		c.NumSchedulers = 0
+	})
+
+	defer s.Shutdown()
+	codec := rpcClient(t, s)
+	testutil.WaitForLeader(t, s.RPC)
+
+	jobID := registerAndVerifyJob(s, t, prefix, 0)
+
+	req := &structs.ResourcesRequest{
+		Prefix:  "",
+		Context: "job",
+	}
+
+	var resp structs.ResourcesResponse
+	if err := msgpackrpc.CallWithCodec(codec, "Resources.List", req, &resp); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	assert.Equal(t, 1, len(resp.Matches["job"]))
+	assert.Equal(t, jobID, resp.Matches["job"][0])
+	assert.NotEqual(t, 0, resp.Index)
+}
+
+// Tests that the zero matches are returned when a prefix has no matching
+// results
+func TestResourcesEndpoint_List_NoMatches(t *testing.T) {
+	prefix := "aaaaaaaa-e8f7-fd38-c855-ab94ceb8970"
+
+	t.Parallel()
+	s := testServer(t, func(c *Config) {
+		c.NumSchedulers = 0
+	})
+
+	defer s.Shutdown()
+	codec := rpcClient(t, s)
+	testutil.WaitForLeader(t, s.RPC)
+
+	req := &structs.ResourcesRequest{
+		Prefix:  prefix,
+		Context: "job",
+	}
+
+	var resp structs.ResourcesResponse
+	if err := msgpackrpc.CallWithCodec(codec, "Resources.List", req, &resp); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	assert.Equal(t, 0, len(resp.Matches["job"]))
+	assert.Equal(t, uint64(0), resp.Index)
 }