chore: have a default connection manager factory

Author: himanshusinghs

eslint-rules/no-config-imports.js

@@ -10,6 +10,10 @@ const allowedConfigValueImportFiles = [
     "src/index.ts",
     // Config resource definition that works with the some config values
     "src/resources/common/config.ts",
+    // The file exports, a factory function to create MCPConnectionManager and
+    // it relies on driver options generator and default driver options from
+    // config file.
+    "src/common/connectionManager.ts",
 ];
 
 // Ref: https://eslint.org/docs/latest/extend/custom-rules

src/common/connectionManager.ts

@@ -4,7 +4,7 @@ import ConnectionString from "mongodb-connection-string-url";
 import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver";
 import { type ConnectionInfo, generateConnectionInfoFromCliArgs } from "@mongosh/arg-parser";
 import type { DeviceId } from "../helpers/deviceId.js";
-import type { DriverOptions, UserConfig } from "./config.js";
+import { defaultDriverOptions, setupDriverConfig, type DriverOptions, type UserConfig } from "./config.js";
 import { MongoDBError, ErrorCodes } from "./errors.js";
 import { type LoggerBase, LogId } from "./logger.js";
 import { packageInfo } from "./packageInfo.js";
@@ -360,3 +360,23 @@ export class MCPConnectionManager extends ConnectionManager {
         }
     }
 }
+
+/**
+ * Consumers of MCP server library have option to bring their own connection
+ * management if they need to. To support that, we enable injecting connection
+ * manager implementation through a factory function.
+ */
+export type ConnectionManagerFactoryFn = (createParams: {
+    logger: LoggerBase;
+    deviceId: DeviceId;
+    userConfig: UserConfig;
+}) => Promise<ConnectionManager>;
+
+export const createMCPConnectionManager: ConnectionManagerFactoryFn = ({ logger, deviceId, userConfig }) => {
+    const driverOptions = setupDriverConfig({
+        config: userConfig,
+        defaults: defaultDriverOptions,
+    });
+
+    return Promise.resolve(new MCPConnectionManager(userConfig, driverOptions, logger, deviceId));
+};

src/index.ts

@@ -36,28 +36,20 @@ function enableFipsIfRequested(): void {
 enableFipsIfRequested();
 
 import { ConsoleLogger, LogId } from "./common/logger.js";
-import { config, driverOptions } from "./common/config.js";
+import { config } from "./common/config.js";
 import crypto from "crypto";
 import { packageInfo } from "./common/packageInfo.js";
 import { StdioRunner } from "./transports/stdio.js";
 import { StreamableHttpRunner } from "./transports/streamableHttp.js";
 import { systemCA } from "@mongodb-js/devtools-proxy-support";
-import type { ConnectionManagerFactoryFn } from "./transports/base.js";
-import { MCPConnectionManager } from "./common/connectionManager.js";
 
 async function main(): Promise<void> {
     systemCA().catch(() => undefined); // load system CA asynchronously as in mongosh
 
     assertHelpMode();
     assertVersionMode();
 
-    const createConnectionManager: ConnectionManagerFactoryFn = ({ logger, deviceId }) =>
-        Promise.resolve(new MCPConnectionManager(config, driverOptions, logger, deviceId));
-
-    const transportRunner =
-        config.transport === "stdio"
-            ? new StdioRunner(config, createConnectionManager)
-            : new StreamableHttpRunner(config, createConnectionManager);
+    const transportRunner = config.transport === "stdio" ? new StdioRunner(config) : new StreamableHttpRunner(config);
     const shutdown = (): void => {
         transportRunner.logger.info({
             id: LogId.serverCloseRequested,

src/lib.ts

@@ -3,11 +3,12 @@ export { Session, type SessionOptions } from "./common/session.js";
 export { defaultUserConfig, type UserConfig } from "./common/config.js";
 export { LoggerBase, type LogPayload, type LoggerType, type LogLevel } from "./common/logger.js";
 export { StreamableHttpRunner } from "./transports/streamableHttp.js";
-export { type ConnectionManagerFactoryFn } from "./transports/base.js";
 export {
     ConnectionManager,
     type AnyConnectionState,
     type ConnectionState,
     type ConnectionStateDisconnected,
+    type ConnectionStateErrored,
+    type ConnectionManagerFactoryFn,
 } from "./common/connectionManager.js";
 export { Telemetry } from "./telemetry/telemetry.js";

src/transports/base.ts

@@ -7,13 +7,8 @@ import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import type { LoggerBase } from "../common/logger.js";
 import { CompositeLogger, ConsoleLogger, DiskLogger, McpLogger } from "../common/logger.js";
 import { ExportsManager } from "../common/exportsManager.js";
-import type { ConnectionManager } from "../common/connectionManager.js";
 import { DeviceId } from "../helpers/deviceId.js";
-
-export type ConnectionManagerFactoryFn = (createParams: {
-    logger: LoggerBase;
-    deviceId: DeviceId;
-}) => Promise<ConnectionManager>;
+import { type ConnectionManagerFactoryFn } from "../common/connectionManager.js";
 
 export abstract class TransportRunnerBase {
     public logger: LoggerBase;
@@ -51,7 +46,11 @@ export abstract class TransportRunnerBase {
 
         const logger = new CompositeLogger(this.logger);
         const exportsManager = ExportsManager.init(this.userConfig, logger);
-        const connectionManager = await this.createConnectionManager({ logger, deviceId: this.deviceId });
+        const connectionManager = await this.createConnectionManager({
+            logger,
+            userConfig: this.userConfig,
+            deviceId: this.deviceId,
+        });
 
         const session = new Session({
             apiBaseUrl: this.userConfig.apiBaseUrl,

src/transports/stdio.ts

@@ -4,8 +4,9 @@ import { JSONRPCMessageSchema } from "@modelcontextprotocol/sdk/types.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { type LoggerBase, LogId } from "../common/logger.js";
 import type { Server } from "../server.js";
-import { type ConnectionManagerFactoryFn, TransportRunnerBase } from "./base.js";
+import { TransportRunnerBase } from "./base.js";
 import { type UserConfig } from "../common/config.js";
+import { createMCPConnectionManager, type ConnectionManagerFactoryFn } from "../common/connectionManager.js";
 
 // This is almost a copy of ReadBuffer from @modelcontextprotocol/sdk
 // but it uses EJSON.parse instead of JSON.parse to handle BSON types
@@ -56,7 +57,7 @@ export class StdioRunner extends TransportRunnerBase {
 
     constructor(
         userConfig: UserConfig,
-        createConnectionManager: ConnectionManagerFactoryFn,
+        createConnectionManager: ConnectionManagerFactoryFn = createMCPConnectionManager,
         additionalLoggers: LoggerBase[] = []
     ) {
         super(userConfig, createConnectionManager, additionalLoggers);

src/transports/streamableHttp.ts

@@ -6,7 +6,8 @@ import { isInitializeRequest } from "@modelcontextprotocol/sdk/types.js";
 import { LogId, type LoggerBase } from "../common/logger.js";
 import { type UserConfig } from "../common/config.js";
 import { SessionStore } from "../common/sessionStore.js";
-import { type ConnectionManagerFactoryFn, TransportRunnerBase } from "./base.js";
+import { TransportRunnerBase } from "./base.js";
+import { createMCPConnectionManager, type ConnectionManagerFactoryFn } from "../common/connectionManager.js";
 
 const JSON_RPC_ERROR_CODE_PROCESSING_REQUEST_FAILED = -32000;
 const JSON_RPC_ERROR_CODE_SESSION_ID_REQUIRED = -32001;
@@ -20,7 +21,7 @@ export class StreamableHttpRunner extends TransportRunnerBase {
 
     constructor(
         userConfig: UserConfig,
-        createConnectionManager: ConnectionManagerFactoryFn,
+        createConnectionManager: ConnectionManagerFactoryFn = createMCPConnectionManager,
         additionalLoggers: LoggerBase[] = []
     ) {
         super(userConfig, createConnectionManager, additionalLoggers);