From fbce8503170578c785e02c1ef4ef8bb0a449ad86 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Mon, 28 Apr 2014 14:52:30 -0700
Subject: [PATCH] agent: Adding nodes UI endpoint

---
 command/agent/http.go             |  4 +++
 command/agent/ui_endpoint.go      | 47 ++++++++++++++++++++++++++++++-
 command/agent/ui_endpoint_test.go | 40 ++++++++++++++++++++++++--
 3 files changed, 87 insertions(+), 4 deletions(-)

diff --git a/command/agent/http.go b/command/agent/http.go
index fd60d6e8c8..47fb42f853 100644
--- a/command/agent/http.go
+++ b/command/agent/http.go
@@ -102,7 +102,11 @@ func (s *HTTPServer) registerHandlers(enableDebug bool) {
 
 	// Enable the UI + special endpoints
 	if s.uiDir != "" {
+		// Static file serving done from /ui/
 		s.mux.Handle("/ui/", http.StripPrefix("/ui/", http.FileServer(http.Dir(s.uiDir))))
+
+		// API's are under /internal/ui/ to avoid conflict
+		s.mux.HandleFunc("/v1/internal/ui/nodes/", s.wrap(s.UINodes))
 	}
 }
 
diff --git a/command/agent/ui_endpoint.go b/command/agent/ui_endpoint.go
index 6bc163dff9..8f7f875ac8 100644
--- a/command/agent/ui_endpoint.go
+++ b/command/agent/ui_endpoint.go
@@ -1,3 +1,48 @@
 package agent
 
-import ()
+import (
+	"github.com/hashicorp/consul/consul/structs"
+	"net/http"
+	"strings"
+)
+
+// UINodes is used to list the nodes in a given datacenter. We return a
+// UINodeList which provides overview information for all the nodes
+func (s *HTTPServer) UINodes(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	// Verify we have some DC, or use the default
+	dc := strings.TrimPrefix(req.URL.Path, "/v1/internal/ui/nodes/")
+	if dc == "" {
+		dc = s.agent.config.Datacenter
+	}
+
+	// Try to ge ta node dump
+	var dump structs.NodeDump
+	if err := s.getNodeDump(resp, dc, &dump); err != nil {
+		return nil, err
+	}
+
+	return dump, nil
+}
+
+// getNodeDump is used to get a dump of all node data. We make a best effort by
+// reading stale data in the case of an availability outage.
+func (s *HTTPServer) getNodeDump(resp http.ResponseWriter, dc string, dump *structs.NodeDump) error {
+	args := structs.DCSpecificRequest{Datacenter: dc}
+	var out structs.IndexedNodeDump
+	defer setMeta(resp, &out.QueryMeta)
+
+START:
+	if err := s.agent.RPC("Internal.NodeDump", &args, &out); err != nil {
+		// Retry the request allowing stale data if no leader. The UI should continue
+		// to function even during an outage
+		if strings.Contains(err.Error(), structs.ErrNoLeader.Error()) && !args.AllowStale {
+			args.AllowStale = true
+			goto START
+		}
+		return err
+	}
+
+	// Set the result
+	*dump = out.Dump
+	return nil
+}
diff --git a/command/agent/ui_endpoint_test.go b/command/agent/ui_endpoint_test.go
index 48de9209ae..56fe223053 100644
--- a/command/agent/ui_endpoint_test.go
+++ b/command/agent/ui_endpoint_test.go
@@ -2,6 +2,7 @@ package agent
 
 import (
 	"bytes"
+	"github.com/hashicorp/consul/consul/structs"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -9,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 )
 
 func TestUiIndex(t *testing.T) {
@@ -28,13 +30,17 @@ func TestUiIndex(t *testing.T) {
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
+	req.URL.Scheme = "http"
+	req.URL.Host = srv.listener.Addr().String()
 
 	// Make the request
-	resp := httptest.NewRecorder()
-	srv.UiIndex(resp, req)
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
 
 	// Verify teh response
-	if resp.Code != 200 {
+	if resp.StatusCode != 200 {
 		t.Fatalf("bad: %v", resp)
 	}
 
@@ -45,3 +51,31 @@ func TestUiIndex(t *testing.T) {
 		t.Fatalf("bad: %s", out.Bytes())
 	}
 }
+
+func TestUiNodes(t *testing.T) {
+	dir, srv := makeHTTPServer(t)
+	defer os.RemoveAll(dir)
+	defer srv.Shutdown()
+	defer srv.agent.Shutdown()
+
+	// Wait for leader
+	time.Sleep(100 * time.Millisecond)
+
+	req, err := http.NewRequest("GET", "/v1/internal/ui/nodes/dc1", nil)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	resp := httptest.NewRecorder()
+	obj, err := srv.UINodes(resp, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	assertIndex(t, resp)
+
+	// Should be 1 node for the server
+	nodes := obj.(structs.NodeDump)
+	if len(nodes) != 1 {
+		t.Fatalf("bad: %v", obj)
+	}
+}