smc-hub
Version:
CoCalc: Backend webserver component
108 lines • 5.11 kB
JavaScript
;
/*
Express middleware for recording metrics about response time to requests.
*/
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
Object.defineProperty(exports, "__esModule", { value: true });
var path_1 = require("path");
var _a = require("smc-hub/metrics-recorder"), get = _a.get, new_histogram = _a.new_histogram;
// initialize metrics
var responseTimeHistogram = new_histogram("http_histogram", "http server", {
buckets: [0.01, 0.1, 1, 2, 5, 10, 20],
labels: ["path", "method", "code"],
});
// response time metrics
function metrics(req, res, next) {
var resFinished = responseTimeHistogram.startTimer();
var originalEnd = res.end;
res.end = function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
originalEnd.apply(res, args);
if (!req.path) {
return;
}
var pathSplit = req.path.split("/");
// for API paths, we want to have data for each endpoint
var path_tail = pathSplit.slice(pathSplit.length - 3);
var is_api = path_tail[0] === "api" && path_tail[1] === "v1";
var path;
if (is_api) {
path = path_tail.join("/");
}
else {
// for regular paths, we ignore the file
path = path_1.dirname(req.path).split("/").slice(0, 2).join("/");
}
resFinished({
path: path,
method: req.method,
code: res.statusCode,
});
};
next();
}
function initMetrics(router) {
var _this = this;
router.use(metrics);
router.get("/metrics", function (_req, res) { return __awaiter(_this, void 0, void 0, function () {
var metricsRecorder, _a, _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
res.header("Content-Type", "text/plain");
res.header("Cache-Control", "private, no-cache, no-store, must-revalidate");
metricsRecorder = get();
if (!(metricsRecorder != null)) return [3 /*break*/, 2];
_b = (_a = res).send;
return [4 /*yield*/, metricsRecorder.metrics()];
case 1:
_b.apply(_a, [_c.sent()]);
return [3 /*break*/, 3];
case 2:
res.send(JSON.stringify({ error: "Metrics recorder not initialized." }));
_c.label = 3;
case 3: return [2 /*return*/];
}
});
}); });
}
exports.default = initMetrics;
//# sourceMappingURL=metrics.js.map