Very basic support for Sentry.

The Sentry package is very useful for monitoring runtime errors. With this PR,
we simply add the necessary mechanism to:

- log to sentry any uncaught error that reaches the toplevel, including startup errors;
- log to sentry any error that we already log internally as `ERROR`.

config/default.yaml

@@ -209,6 +209,20 @@ health:
     # Defaults to 418.
     unhealthyStatus: 418
 
+  # Sentry options. Sentry is a tool used to receive/collate/triage runtime
+  # errors and performance issues. Skip this section if you do not wish to use
+  # Sentry.
+  sentry:
+    # The key used to upload Sentry data to the server.
+    # dsn: "https://XXXXXXXXX@example.com/YYY
+
+    # Frequency of performance monitoring.
+    # A number in [0.0, 1.0], where 0.0 means "don't bother with tracing"
+    # and 1.0 means "trace performance at every opportunity".
+    # tracesSampleRate: 0.5
+
+
+
 # Options for exposing web APIs.
 web:
   # Whether to enable web APIs.

package.json

@@ -44,6 +44,8 @@
     "typescript-formatter": "^7.2"
   },
   "dependencies": {
+    "@sentry/node": "^7.17.2",
+    "@sentry/tracing": "^7.17.2",
     "await-lock": "^2.2.2",
     "body-parser": "^1.20.1",
     "config": "^3.3.8",

src/ManagementRoomOutput.ts

@@ -14,6 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import * as Sentry from "@sentry/node";
 import { extractRequestError, LogLevel, LogService, MatrixClient, MessageType, Permalinks, TextualMessageEventContent, UserID } from "matrix-bot-sdk";
 import { IConfig } from "./config";
 import { htmlEscape } from "./utils";
@@ -34,7 +35,7 @@ export default class ManagementRoomOutput {
         private readonly managementRoomId: string,
         private readonly client: MatrixClient,
         private readonly config: IConfig,
-        ) {
+    ) {
 
     }
 
@@ -94,6 +95,9 @@ export default class ManagementRoomOutput {
      * @param isRecursive Whether logMessage is being called from logMessage.
      */
     public async logMessage(level: LogLevel, module: string, message: string | any, additionalRoomIds: string[] | string | null = null, isRecursive = false): Promise<any> {
+        if (level === LogLevel.ERROR) {
+            Sentry.captureMessage(`${module}: ${message}`, 'error');
+        }
         if (!additionalRoomIds) additionalRoomIds = [];
         if (!Array.isArray(additionalRoomIds)) additionalRoomIds = [additionalRoomIds];
 
@@ -115,7 +119,12 @@ export default class ManagementRoomOutput {
                 evContent = await this.replaceRoomIdsWithPills(clientMessage, new Set(roomIds), "m.notice");
             }
 
-            await client.sendMessage(this.managementRoomId, evContent);
+            try {
+                await client.sendMessage(this.managementRoomId, evContent);
+            } catch (ex) {
+                // We want to be informed if we cannot log a message.
+                Sentry.captureException(ex);
+            }
         }
 
         levelToFn[level.toString()](module, message);

src/Mjolnir.ts

@@ -319,11 +319,10 @@ export class Mjolnir {
                 LogService.error("Mjolnir", extractRequestError(err));
                 this.stop();
                 await this.managementRoomOutput.logMessage(LogLevel.ERROR, "Mjolnir@startup", "Startup failed due to error - see console");
-                throw err;
             } catch (e) {
                 LogService.error("Mjolnir", `Failed to report startup error to the management room: ${e}`);
-                throw err;
             }
+            throw err;
         }
     }
 
@@ -602,3 +601,4 @@ export class Mjolnir {
         }
     }
 }
+

src/config.ts

@@ -84,6 +84,16 @@ export interface IConfig {
             healthyStatus: number;
             unhealthyStatus: number;
         };
+        // If specified, attempt to upload any crash statistics to sentry.
+        sentry?: {
+            dsn: string;
+
+            // Frequency of performance monitoring.
+            //
+            // A number in [0.0, 1.0], where 0.0 means "don't bother with tracing"
+            // and 1.0 means "trace performance at every opportunity".
+            tracesSampleRate: number;
+        };
     };
     web: {
         enabled: boolean;

src/index.ts

@@ -15,6 +15,9 @@ limitations under the License.
 */
 
 import * as path from "path";
+
+import { Healthz } from "./health/healthz";
+
 import {
     LogLevel,
     LogService,
@@ -23,10 +26,10 @@ import {
     RichConsoleLogger,
     SimpleFsStorageProvider
 } from "matrix-bot-sdk";
+
 import { read as configRead } from "./config";
-import { Healthz } from "./health/healthz";
 import { Mjolnir } from "./Mjolnir";
-import { patchMatrixClient } from "./utils";
+import { initializeSentry, patchMatrixClient } from "./utils";
 
 
 (async function () {
@@ -39,6 +42,10 @@ import { patchMatrixClient } from "./utils";
 
     LogService.info("index", "Starting bot...");
 
+    // Initialize error reporting as early as possible.
+    if (config.health.sentry) {
+        initializeSentry(config);
+    }
     const healthz = new Healthz(config);
     healthz.isHealthy = false; // start off unhealthy
     if (config.health.healthz.enabled) {

src/utils.ts

@@ -24,7 +24,11 @@ import {
 } from "matrix-bot-sdk";
 import { ClientRequest, IncomingMessage } from "http";
 import { default as parseDuration } from "parse-duration";
+import * as Sentry from '@sentry/node';
+import * as _ from '@sentry/tracing'; // Performing the import activates tracing.
+
 import ManagementRoomOutput from "./ManagementRoomOutput";
+import { IConfig } from "./config";
 
 // Define a few aliases to simplify parsing durations.
 
@@ -396,3 +400,27 @@ export function patchMatrixClient() {
     patchMatrixClientForConciseExceptions();
     patchMatrixClientForRetry();
 }
+
+/**
+ * Initialize Sentry for error monitoring and reporting.
+ *
+ * This method is idempotent. If `config` specifies that Sentry
+ * should not be used, it does nothing.
+ */
+export function initializeSentry(config: IConfig) {
+    if (sentryInitialized) {
+        return;
+    }
+    if (config.health.sentry) {
+        // Configure error monitoring with Sentry.
+        let sentry = config.health.sentry;
+        Sentry.init({
+            dsn: sentry.dsn,
+            tracesSampleRate: sentry.tracesSampleRate,
+        });
+        sentryInitialized = true;
+    }
+}
+// Set to `true` once we have initialized `Sentry` to ensure
+// that we do not attempt to initialize it more than once.
+let sentryInitialized = false;

test/integration/mjolnirSetupUtils.ts

@@ -23,7 +23,7 @@ import {
 } from "matrix-bot-sdk";
 import { Mjolnir}  from '../../src/Mjolnir';
 import { overrideRatelimitForUser, registerUser } from "./clientHelper";
-import { patchMatrixClient } from "../../src/utils";
+import { initializeSentry, patchMatrixClient } from "../../src/utils";
 import { IConfig } from "../../src/config";
 
 /**
@@ -49,6 +49,8 @@ export async function ensureAliasedRoomExists(client: MatrixClient, alias: strin
 }
 
 async function configureMjolnir(config: IConfig) {
+    // Initialize error monitoring as early as possible.
+    initializeSentry(config);
     try {
         await registerUser(config.homeserverUrl, config.pantalaimon.username, config.pantalaimon.username, config.pantalaimon.password, true)
     } catch (e) {

yarn.lock

@@ -104,6 +104,51 @@
     domhandler "^4.2.0"
     selderee "^0.6.0"
 
+"@sentry/core@7.22.0":
+  version "7.22.0"
+  resolved "https://registry.yarnpkg.com/@sentry/core/-/core-7.22.0.tgz#8e50f288e5e8fcaa2774daffd2487e042a392893"
+  integrity sha512-qYJiJrL1mfQQln84mNunBRUkXq7xDGQQoNh4Sz9VYP5698va51zmS5BLYRCZ5CkPwRYNuhUqlUXN7bpYGYOOIA==
+  dependencies:
+    "@sentry/types" "7.22.0"
+    "@sentry/utils" "7.22.0"
+    tslib "^1.9.3"
+
+"@sentry/node@^7.17.2":
+  version "7.22.0"
+  resolved "https://registry.yarnpkg.com/@sentry/node/-/node-7.22.0.tgz#d575481e56d3326ad457378db5ab7cc804b712fd"
+  integrity sha512-jKhxqKsbEEaY/g3FTzpj1fwukN0IkNv4V+0Fl+t/EmSNUL/7q5FMmDBa+fFQuQzwps8UEpzqPOzMSRapVsoP0w==
+  dependencies:
+    "@sentry/core" "7.22.0"
+    "@sentry/types" "7.22.0"
+    "@sentry/utils" "7.22.0"
+    cookie "^0.4.1"
+    https-proxy-agent "^5.0.0"
+    lru_map "^0.3.3"
+    tslib "^1.9.3"
+
+"@sentry/tracing@^7.17.2":
+  version "7.22.0"
+  resolved "https://registry.yarnpkg.com/@sentry/tracing/-/tracing-7.22.0.tgz#ec29325ee2c5959670097c104e47a78797cef17b"
+  integrity sha512-s68aSnrRaWQ+Z5oG9ozIegUkofZy9PwicuXYEPA8K/R30F1CVpHvDZ/3KlFnByl+aXTbAyLBQzN2sAObB5g4pQ==
+  dependencies:
+    "@sentry/core" "7.22.0"
+    "@sentry/types" "7.22.0"
+    "@sentry/utils" "7.22.0"
+    tslib "^1.9.3"
+
+"@sentry/types@7.22.0":
+  version "7.22.0"
+  resolved "https://registry.yarnpkg.com/@sentry/types/-/types-7.22.0.tgz#58e4ce77b523048e0f31e2ea4b597946d76f6079"
+  integrity sha512-LhCL+wb1Jch+OesB2CIt6xpfO1Ab6CRvoNYRRzVumWPLns1T3ZJkarYfhbLaOEIb38EIbPgREdxn2AJT560U4Q==
+
+"@sentry/utils@7.22.0":
+  version "7.22.0"
+  resolved "https://registry.yarnpkg.com/@sentry/utils/-/utils-7.22.0.tgz#fb46dc2761e2d44cf70bc3e1fba61d55852904b5"
+  integrity sha512-1GiNw1opIngxg0nktCTc9wibh4/LV12kclrnB9dAOHrqazZXHXZRAkjqrhQphKcMpT+3By91W6EofjaDt5a/hg==
+  dependencies:
+    "@sentry/types" "7.22.0"
+    tslib "^1.9.3"
+
 "@tootallnate/once@1":
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/@tootallnate/once/-/once-1.1.2.tgz#ccb91445360179a04e7fe6aff78c00ffc1eeaf82"
@@ -829,6 +874,11 @@ cookie@0.5.0:
   resolved "https://registry.yarnpkg.com/cookie/-/cookie-0.5.0.tgz#d1f5d71adec6558c58f389987c366aa47e994f8b"
   integrity sha512-YZ3GUyn/o8gfKJlnlX7g7xq4gyO6OSuhGPKaaGssGB2qgDUS0gPgtTvoyZLTt9Ab6dC4hfc9dV5arkvc/OCmrw==
 
+cookie@^0.4.1:
+  version "0.4.2"
+  resolved "https://registry.yarnpkg.com/cookie/-/cookie-0.4.2.tgz#0e41f24de5ecf317947c82fc789e06a884824432"
+  integrity sha512-aSWTXFzaKWkvHO1Ny/s+ePFpvKsPnjc551iI41v3ny/ow6tBG5Vd+FuqGNhh1LxOmVzOlGUriIlOaokOvhaStA==
+
 core-util-is@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
@@ -2203,6 +2253,11 @@ lru-cache@^7.10.1:
   resolved "https://registry.yarnpkg.com/lru-cache/-/lru-cache-7.13.1.tgz#267a81fbd0881327c46a81c5922606a2cfe336c4"
   integrity sha512-CHqbAq7NFlW3RSnoWXLJBxCWaZVBrfa9UEHId2M3AW8iEBurbqduNexEUCGc3SHc6iCYXNJCDi903LajSVAEPQ==
 
+lru_map@^0.3.3:
+  version "0.3.3"
+  resolved "https://registry.yarnpkg.com/lru_map/-/lru_map-0.3.3.tgz#b5c8351b9464cbd750335a79650a0ec0e56118dd"
+  integrity sha512-Pn9cox5CsMYngeDbmChANltQl+5pi6XmTrraMSzhPmMBbmgcxmqWry0U3PGapCU1yB4/LqCcom7qhHZiF/jGfQ==
+
 make-error@^1.1.1:
   version "1.3.6"
   resolved "https://registry.yarnpkg.com/make-error/-/make-error-1.3.6.tgz#2eb2e37ea9b67c4891f684a1394799af484cf7a2"
@@ -3436,9 +3491,9 @@ tsconfig-paths@^3.5.0:
     minimist "^1.2.0"
     strip-bom "^3.0.0"
 
-tslib@^1.13.0, tslib@^1.8.1:
+tslib@^1.13.0, tslib@^1.8.1, tslib@^1.9.3:
   version "1.14.1"
-  resolved "https://registry.npmjs.org/tslib/-/tslib-1.14.1.tgz"
+  resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.14.1.tgz#cf2d38bdc34a134bcaf1091c41f6619e2f672d00"
   integrity sha512-Xni35NKzjgMrwevysHTCArtLDpPvye8zV/0E4EyYn43P7/7qvQwPh9BGkHewbMulVntbigmcT7rdX3BNo9wRJg==
 
 tslint@^6.1.3: