很多mongodb操作进行之前需要先启动mongod,然后使用mongo shell连接，因此总结一篇通用操作流程。

启动mongod

执行$ mongod --config /Users/chenxin/Workspaces/mongo/conf/mongod.conf启动本机上安装的mongod服务：

2018-07-10T13:53:14.872+0800 F CONTROL  [main] Failed global initialization: FileNotOpen: logpath "/Users/chenxin/logs/db/mongodb" should name a file, not a directory.

可见配置文件中logpath配置错误，修改mongod.conf为：

systemLog:
  destination: file
  path: /Users/chenxin/logs/db/mongodb/mongo.log
  logAppend: true
storage:
  dbPath: /Users/chenxin/data/db/mongodb
net:
  bindIp: 127.0.0.1

重新启动mongod成功。

连接本地mongod服务

重新打开一个终端，执行$ mongo:

MongoDB shell version v3.6.5
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.6.5
Server has startup warnings: 
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] 
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] 
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] 
2018-07-10T13:54:37.728+0800 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000
>

成功连接，使用show dbs查看已经存在的数据库：

admin   0.000GB
config  0.000GB
local   0.000GB