由于工作的需要，需要 mongo shell 去调取 Js 代码，达到 mongo 分片集群部署的完全自动化。mongo 的 shell 就是用 javascript 集成的。所以有了这一次的经历，但是这个 javascript 又和前端的 Js 写法稍有区别。

官档链接:

https://docs.mongodb.com/manual/tutorial/write-scripts-for-the-mongo-shell/ 中明确指明 mongo 是支持 Js 的，如图。

接下来我们大体看一下代码：每一个 function 代表是一个 Js 文件。

function establish_config_service(replset_name, master_ip, slave_ip, arbiter_ip, port){
print("naster_ip:",master_ip)
print("welcome to mongodb......");
config={_id:`${replset_name}`,members:[{_id:0,host:`${master_ip}:${port}`},{_id:1,host:`${slave_ip}:${port}`},{_id:2,host:`${arbiter_ip}:${port}`}]
};
ret=rs.initiate(config);
}var replset_name=''
var master_ip=''
var slave_ip=''
var arbiter_ip=''
var port=''print("Initialize configuration service for mongodb culster");
establish_config_service(replset_name, master_ip, slave_ip, arbiter_ip, port);
print("Initialization configuration service complete for mongodb cluster");

function establish_primary_shard1_service(replset_name, master_ip, slave_ip, arbiter_ip, port){
config={_id:`${replset_name}`,members:[{_id:0,host:`${master_ip}:${port}`},{_id:1,host:`${slave_ip}:${port}`},{_id:2,host:`${arbiter_ip}:${port}`,arbiterOnly:true}]
};
ret=rs.initiate(config);
}var replset_name=''
var master_ip=''
var slave_ip=''
var arbiter_ip=''
var port=''print("Initialize primary shard1 service for mongodb culster")
establish_primary_shard1_service(replset_name, master_ip, slave_ip, arbiter_ip, port)
print("Initialize primary shard1 service complete for mongodb cluster")

function establish_primary_shard2_service(replset_name, master_ip, slave_ip, arbiter_ip, port){
config={_id:`${replset_name}`,members:[{_id:0,host:`${arbiter_ip}:${port}`,arbiterOnly:true},{_id:1,host:`${master_ip}:${port}`},{_id:2,host:`${slave_ip}:${port}`}]
};
ret=rs.initiate(config);}var replset_name=''
var master_ip=''
var slave_ip=''
var arbiter_ip=''
var port=''print("Initialize primary shard2 service for mongodb culster")
establish_primary_shard2_service(replset_name, master_ip, slave_ip, arbiter_ip, port)
print("Initialize primary shard2 service complete for mongodb cluster")

function establish_primary_shard3_service(replset_name, master_ip, slave_ip, arbiter_ip, port){
config={_id:`${replset_name}`,members:[{_id:0,host:`${slave_ip}:${port}`},{_id:1,host:`${arbiter_ip}:${port}`,arbiterOnly:true},{_id:2,host:`${master_ip}:${port}`}]
};
rs.initiate(config);
}var replset_name=''
var master_ip=''
var slave_ip=''
var arbiter_ip=''
var port=''print("Initialize primary shard3 service for mongodb culster")
establish_primary_shard3_service(replset_name, master_ip, slave_ip, arbiter_ip, port)
print("Initialize primary shard3 service complete for mongodb cluster")

function auth(user, password){
db.createUser({user: `${user}`,pwd: `${password}`,roles: [ { role: "root", db: "admin" } ]})
db.auth({user: `${user}`,pwd: `${password}`})
}var user=''
var password=''auth(user,password)

function set_balancer_time_span(start_time, stop_time){db.settings.update({ _id: "balancer" },{ $set: { activeWindow : { start : `${start_time}`, stop : `${stop_time}` } } },{ upsert: true })
}var start_time=''
var stop_time=''print("Setting balancer start_time for mongodb culster")
set_balancer_time_span(start_time, stop_time)
print("Setting balancer stop_time for mongodb culster")

print('=========BEGIN==========');
conn = new Mongo("192.168.43.43:37017");
db = conn.getDB("config");
db.adminCommand('listDatabases');
db.settings.update({ _id : "balancer" }, { $set : { activeWindow : { start : "3:00", stop : "5:00" } } }, true )
db = conn.getDB("admin");
print('=========END==========');

代码基本上写完，接下来我们去调取一下其中的一个js。开启 mongo 的时间均衡窗口。

[root@mms mongo]# cat 1.js
print('=========BEGIN==========');
conn = new Mongo("192.168.43.43:37017");
db = conn.getDB("config");
db.adminCommand('listDatabases');
db.settings.update({ _id : "balancer" }, { $set : { activeWindow : { start : "3:00", stop : "5:00" } } }, true )
db = conn.getDB("admin");
print('=========END==========');[root@mms mongo]# ps -ef | grep -v grep | grep mongo
mongo     11670      1  0 16:20 ?        00:01:36 mongod -f /opt/mongo/conf/mongodb.conf
[root@mms mongo]#
[root@mms mongo]# mongo --port 37017 1.js
MongoDB shell version: 3.2.12
connecting to: 127.0.0.1:37017/test
=========BEGIN==========
=========END==========
[root@mms mongo]# mongo --port 37017
MongoDB shell version: 3.2.12
connecting to: 127.0.0.1:37017/test
> use config
switched to db config
> db.settings.find()
{ "_id" : "balancer", "activeWindow" : { "start" : "3:00", "stop" : "5:00" } }
>

可以看到自动可以把 Js 加载进去，就无需再数据库里面进行设置了。所有的自动化基本上都是利用 Js 去完成的。

又找到了刚毕业时写代码的感觉，透心凉。。。