http: adding alloc lookup endpoint

command/agent/alloc_endpoint.go

@@ -28,24 +28,25 @@ func (s *HTTPServer) AllocsRequest(resp http.ResponseWriter, req *http.Request)
 
 func (s *HTTPServer) AllocSpecificRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
 	allocID := strings.TrimPrefix(req.URL.Path, "/v1/allocation/")
-	switch req.Method {
-	case "GET":
-		return s.allocQuery(resp, req, allocID)
-	case "DELETE":
-		return s.allocDelete(resp, req, allocID)
-	default:
+	if req.Method != "GET" {
 		return nil, CodedError(405, ErrInvalidMethod)
 	}
-}
 
-func (s *HTTPServer) allocQuery(resp http.ResponseWriter, req *http.Request,
-	allocID string) (interface{}, error) {
-	// TODO
-	return nil, nil
-}
+	args := structs.AllocSpecificRequest{
+		AllocID: allocID,
+	}
+	if s.parse(resp, req, &args.Region, &args.QueryOptions) {
+		return nil, nil
+	}
 
-func (s *HTTPServer) allocDelete(resp http.ResponseWriter, req *http.Request,
-	allocID string) (interface{}, error) {
-	// TODO
-	return nil, nil
+	var out structs.SingleAllocResponse
+	if err := s.agent.RPC("Alloc.GetAlloc", &args, &out); err != nil {
+		return nil, err
+	}
+
+	setMeta(resp, &out.QueryMeta)
+	if out.Alloc == nil {
+		return nil, CodedError(404, "alloc not found")
+	}
+	return out.Alloc, nil
 }

command/agent/alloc_endpoint_test.go

@@ -52,3 +52,46 @@ func TestHTTP_AllocsList(t *testing.T) {
 		}
 	})
 }
+
+func TestHTTP_AllocQuery(t *testing.T) {
+	httpTest(t, nil, func(s *TestServer) {
+		// Directly manipulate the state
+		state := s.Agent.server.State()
+		alloc := mock.Alloc()
+		err := state.UpdateAllocations(1000,
+			[]*structs.Allocation{alloc})
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// Make the HTTP request
+		req, err := http.NewRequest("GET", "/v1/allocation/"+alloc.ID, nil)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respW := httptest.NewRecorder()
+
+		// Make the request
+		obj, err := s.Server.AllocSpecificRequest(respW, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// Check for the index
+		if respW.HeaderMap.Get("X-Nomad-Index") == "" {
+			t.Fatalf("missing index")
+		}
+		if respW.HeaderMap.Get("X-Nomad-KnownLeader") != "true" {
+			t.Fatalf("missing known leader")
+		}
+		if respW.HeaderMap.Get("X-Nomad-LastContact") == "" {
+			t.Fatalf("missing last contact")
+		}
+
+		// Check the job
+		a := obj.(*structs.Allocation)
+		if a.ID != alloc.ID {
+			t.Fatalf("bad: %#v", a)
+		}
+	})
+}