chore: refactor config initialisation for CLI to allow easy extension from other config sources as well MCP-288

scripts/generateArguments.ts

@@ -14,7 +14,7 @@ import { fileURLToPath } from "url";
 import { UserConfigSchema, configRegistry } from "../src/common/config.js";
 import assert from "assert";
 import { execSync } from "child_process";
-import { OPTIONS } from "../src/common/argsParserOptions.js";
+import { OPTIONS } from "../src/common/config/argsParserOptions.js";
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);

src/common/config.ts

@@ -1,5 +1,5 @@
 import argv from "yargs-parser";
-import type { CliOptions, ConnectionInfo } from "@mongosh/arg-parser";
+import type { CliOptions } from "@mongosh/arg-parser";
 import { generateConnectionInfoFromCliArgs } from "@mongosh/arg-parser";
 import { Keychain } from "./keychain.js";
 import type { Secret } from "./keychain.js";
@@ -11,8 +11,8 @@ import {
     getLogPath,
     isConnectionSpecifier,
     validateConfigKey,
-} from "./configUtils.js";
-import { OPTIONS } from "./argsParserOptions.js";
+} from "./config/configUtils.js";
+import { OPTIONS } from "./config/argsParserOptions.js";
 import { similarityValues, previewFeatureValues } from "./schemas.js";
 
 export const configRegistry = z4.registry<ConfigFieldMeta>();
@@ -183,20 +183,6 @@ export const config = setupUserConfig({
     env: process.env,
 });
 
-export type DriverOptions = ConnectionInfo["driverOptions"];
-export const defaultDriverOptions: DriverOptions = {
-    readConcern: {
-        level: "local",
-    },
-    readPreference: "secondaryPreferred",
-    writeConcern: {
-        w: "majority",
-    },
-    timeoutMS: 30_000,
-    proxy: { useEnvironmentVariableProxies: true },
-    applyProxyToOIDC: true,
-};
-
 // Gets the config supplied by the user as environment variables. The variable names
 // are prefixed with `MDB_MCP_` and the keys match the UserConfig keys, but are converted
 // to SNAKE_UPPER_CASE.
@@ -414,17 +400,3 @@ export function setupUserConfig({ cli, env }: { cli: string[]; env: Record<strin
     registerKnownSecretsInRootKeychain(userConfig);
     return userConfig;
 }
-
-export function setupDriverConfig({
-    config,
-    defaults,
-}: {
-    config: UserConfig;
-    defaults: Partial<DriverOptions>;
-}): DriverOptions {
-    const { driverOptions } = generateConnectionInfoFromCliArgs(config);
-    return {
-        ...defaults,
-        ...driverOptions,
-    };
-}

src/common/connectionManager.ts

@@ -2,9 +2,9 @@ import { EventEmitter } from "events";
 import type { MongoClientOptions } from "mongodb";
 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 ConnectionInfo } from "@mongosh/arg-parser";
 import type { DeviceId } from "../helpers/deviceId.js";
-import { defaultDriverOptions, setupDriverConfig, type DriverOptions, type UserConfig } from "./config.js";
+import { type UserConfig } from "./config.js";
 import { MongoDBError, ErrorCodes } from "./errors.js";
 import { type LoggerBase, LogId } from "./logger.js";
 import { packageInfo } from "./packageInfo.js";
@@ -17,8 +17,8 @@ export interface AtlasClusterConnectionInfo {
     expiryDate: Date;
 }
 
-export interface ConnectionSettings {
-    connectionString: string;
+export interface ConnectionSettings extends Omit<ConnectionInfo, "driverOptions"> {
+    driverOptions?: ConnectionInfo["driverOptions"];
     atlas?: AtlasClusterConnectionInfo;
 }
 
@@ -136,7 +136,6 @@ export class MCPConnectionManager extends ConnectionManager {
 
     constructor(
         private userConfig: UserConfig,
-        private driverOptions: DriverOptions,
         private logger: LoggerBase,
         deviceId: DeviceId,
         bus?: EventEmitter
@@ -157,7 +156,6 @@ export class MCPConnectionManager extends ConnectionManager {
         }
 
         let serviceProvider: Promise<NodeDriverServiceProvider>;
-        let connectionInfo: ConnectionInfo;
         let connectionStringAuthType: ConnectionStringAuthType = "scram";
 
         try {
@@ -173,11 +171,10 @@ export class MCPConnectionManager extends ConnectionManager {
                 components: appNameComponents,
             });
 
-            connectionInfo = generateConnectionInfoFromCliArgs({
-                ...this.userConfig,
-                ...this.driverOptions,
-                connectionSpecifier: settings.connectionString,
-            });
+            const connectionInfo = {
+                connectionString: settings.connectionString,
+                driverOptions: settings.driverOptions ?? {},
+            };
 
             if (connectionInfo.driverOptions.oidc) {
                 connectionInfo.driverOptions.oidc.allowedFlows ??= ["auth-code"];
@@ -394,10 +391,5 @@ export type ConnectionManagerFactoryFn = (createParams: {
 }) => 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));
+    return Promise.resolve(new MCPConnectionManager(userConfig, logger, deviceId));
 };

src/resources/common/config.ts

@@ -1,8 +1,8 @@
 import { ReactiveResource } from "../resource.js";
-import { defaultDriverOptions } from "../../common/config.js";
 import type { UserConfig } from "../../common/config.js";
 import type { Telemetry } from "../../telemetry/telemetry.js";
 import type { Session } from "../../lib.js";
+import { generateConnectionInfoFromCliArgs } from "@mongosh/arg-parser";
 
 export class ConfigResource extends ReactiveResource<UserConfig, readonly []> {
     constructor(session: Session, config: UserConfig, telemetry: Telemetry) {
@@ -32,13 +32,14 @@ export class ConfigResource extends ReactiveResource<UserConfig, readonly []> {
     }
 
     toOutput(): string {
+        const connectionInfo = generateConnectionInfoFromCliArgs(this.current);
         const result = {
             telemetry: this.current.telemetry,
             logPath: this.current.logPath,
-            connectionString: this.current.connectionString
+            connectionString: connectionInfo.connectionString
                 ? "set; access to MongoDB tools are currently available to use"
                 : "not set; before using any MongoDB tool, you need to configure a connection string, alternatively you can setup MongoDB Atlas access, more info at 'https://github.com/mongodb-js/mongodb-mcp-server'.",
-            connectOptions: defaultDriverOptions,
+            connectOptions: connectionInfo.driverOptions,
             atlas:
                 this.current.apiClientId && this.current.apiClientSecret
                     ? "set; MongoDB Atlas tools are currently available to use"

src/server.ts

@@ -1,3 +1,4 @@
+import { generateConnectionInfoFromCliArgs } from "@mongosh/arg-parser";
 import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import type { Session } from "./common/session.js";
 import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
@@ -308,9 +309,11 @@ export class Server {
                     context: "server",
                     message: `Detected a MongoDB connection string in the configuration, trying to connect...`,
                 });
-                await this.session.connectToMongoDB({
-                    connectionString: this.userConfig.connectionString,
+                const connectionInfo = generateConnectionInfoFromCliArgs({
+                    ...this.userConfig,
+                    connectionSpecifier: this.userConfig.connectionString,
                 });
+                await this.session.connectToMongoDB(connectionInfo);
             } catch (error) {
                 // We don't throw an error here because we want to allow the server to start even if the connection string is invalid.
                 this.session.logger.error({