mongo/jstests/auth/shell.js

// Authenticate to a mongod from the shell via command line.

const port = allocatePort();
const mongod = MongoRunner.runMongod({auth: "", port: port});
const admin = mongod.getDB("admin");

admin.createUser({user: "admin", pwd: "pass", roles: jsTest.adminUserRoles});

// Connect via shell round-trip in order to verify handling of mongodb:// uri with password.
const uri = "mongodb://admin:pass@localhost:" + port + "/admin";
// Be sure to actually do something requiring authentication.
const mongo = runMongoProgram("mongo", uri, "--eval", "db.system.users.find({});");
assert.eq(mongo, 0, "Failed connecting to mongod via shell+mongodb uri");

MongoRunner.stopMongod(mongod);