agent: Support server-side filtering of passing checks. Fixes #57.

command/agent/health_endpoint.go

@@ -106,5 +106,26 @@ func (s *HTTPServer) HealthServiceNodes(resp http.ResponseWriter, req *http.Requ
 	if err := s.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
 		return nil, err
 	}
+
+	// Filter to only passing if specified
+	if _, ok := params["passing"]; ok {
+		out.Nodes = filterNonPassing(out.Nodes)
+	}
 	return out.Nodes, nil
 }
+
+// filterNonPassing is used to filter out any nodes that have check that are not passing
+func filterNonPassing(nodes structs.CheckServiceNodes) structs.CheckServiceNodes {
+	n := len(nodes)
+	for i := 0; i < n; i++ {
+		node := nodes[i]
+		for _, check := range node.Checks {
+			if check.Status != structs.HealthPassing {
+				nodes[i], nodes[n-1] = nodes[n-1], structs.CheckServiceNode{}
+				n--
+				i--
+			}
+		}
+	}
+	return nodes[:n]
+}

command/agent/health_endpoint_test.go

@@ -138,3 +138,48 @@ func TestHealthServiceNodes(t *testing.T) {
 		t.Fatalf("bad: %v", obj)
 	}
 }
+
+func TestHealthServiceNodes_PassingFilter(t *testing.T) {
+	dir, srv := makeHTTPServer(t)
+	defer os.RemoveAll(dir)
+	defer srv.Shutdown()
+	defer srv.agent.Shutdown()
+
+	// Wait for a leader
+	time.Sleep(100 * time.Millisecond)
+
+	// Create a failing service check
+	args := &structs.RegisterRequest{
+		Datacenter: "dc1",
+		Node:       srv.agent.config.NodeName,
+		Address:    "127.0.0.1",
+		Check: &structs.HealthCheck{
+			Node:      srv.agent.config.NodeName,
+			Name:      "consul check",
+			ServiceID: "consul",
+			Status:    structs.HealthCritical,
+		},
+	}
+	var out struct{}
+	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	req, err := http.NewRequest("GET", "/v1/health/service/consul?passing", nil)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	resp := httptest.NewRecorder()
+	obj, err := srv.HealthServiceNodes(resp, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	assertIndex(t, resp)
+
+	// Should be 0 health check for consul
+	nodes := obj.(structs.CheckServiceNodes)
+	if len(nodes) != 0 {
+		t.Fatalf("bad: %v", obj)
+	}
+}

website/source/docs/agent/http.html.markdown

@@ -681,6 +681,10 @@ endpoint automatically returns the status of the associated health check,
 as well as any system level health checks. This allows a client to avoid
 sending traffic to nodes failing health tests, or who are reporting warnings.
 
+Providing the "?passing" query parameter will filter results to only nodes
+with all checks in the passing state. This can be used to avoid some filtering
+logic on the client side. (Added in Consul 0.2)
+
 Users can also built in support for dynamic load balancing and other features
 by incorporating the use of health checks.