和其他所有数据库一样，权限的管理都差不多一样。mongodb存储所有的用户信息在admin 数据库的集合system.users中，保存用户名、密码和数据库信息。mongodb默认不启用授权认证，只要能连接到该服务器，就可连接到mongod。若要启用安全认证，需要更改配置文件参数auth。

以下测试理解

查看数据库：

> show dbs

发现 admin 竟然没有！~

找了好久，找不到相关说明，于是直接创建用户admin

use admindb.createUser({user: "admin",pwd: "admin",roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]}
)

成功创建，再查询admin中的集合，有数据了！

> show collections
system.indexes
system.users
system.version

查看3个集合的信息：

> db.system.users.find();
{ "_id" : "admin.admin", "user" : "admin", "db" : "admin", "credentials" : { "SCRAM-SHA-1" : { "iterationCount" : 10000, "salt" : "cFISfpbm04pmIFpqiL340g==", "storedKey" : "WG1DSEEEHUZUBjsjsnEA4RFVY2M=", "serverKey" : "9Lm+IX6l9kfaE/4C25/ghsQpDkE=" } }, "roles" : [ { "role" : "userAdminAnyDatabase", "db" : "admin" } ] }
>
> db.system.indexes.find();
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "admin.system.version" }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "admin.system.users" }
{ "v" : 1, "unique" : true, "key" : { "user" : 1, "db" : 1 }, "name" : "user_1_db_1", "ns" : "admin.system.users" }
>
> db.system.version.find();
{ "_id" : "authSchema", "currentVersion" : 5 }
>

现在启用 auth：
[root@localhost ~]# vi /etc/mongod.conf

auth=true

重启 mongod 服务：

[root@localhost ~]# service mongod restart

直接默认登录，查看集合，发现无权操作了：

[root@localhost ~]# mongo

[root@localhost ~]# mongo
MongoDB shell version: 3.0.2
connecting to: test
> show dbs
2015-05-09T21:57:03.176-0700 E QUERY    Error: listDatabases failed:{"ok" : 0,"errmsg" : "not authorized on admin to execute command { listDatabases: 1.0 }","code" : 13
}at Error (<anonymous>)at Mongo.getDBs (src/mongo/shell/mongo.js:47:15)at shellHelper.show (src/mongo/shell/utils.js:630:33)at shellHelper (src/mongo/shell/utils.js:524:36)at (shellhelp2):1:1 at src/mongo/shell/mongo.js:47
>

刚才在数据库 admin 创建了一个账户 admin ，先到数据admin进来连接（其他db则失败）：

[root@localhost ~]# mongo
MongoDB shell version: 3.0.2
connecting to: test
>
> db.auth("admin","admin")
Error: 18 Authentication failed.
0
> use mydb
switched to db mydb
> db.auth("admin","admin")
Error: 18 Authentication failed.
0
> use admin
switched to db admin
> db.auth("admin","admin")
1
>

db.auth("admin","admin") 返回值为1，说明登录成功！~db.auth("admin","admin") 记录是不存在的，执行完后这一行在shell中不会记录历史。

所以现在创建另一个用户"myuser"

db.createUser({user: "myuser",pwd: "myuser",roles: [ { role: "readWrite", db: "mydb" } ]}
)

也可以增删角色：

#授予角色：db.grantRolesToUser( "userName" , [ { role: "<role>", db: "<database>" } ])db.grantRolesToUser( "myuser" , [ { role: "dbOwner", db: "mydb" } ])#取消角色：db.grantRolesToUser( "userName" , [ { role: "<role>", db: "<database>" } ])db.revokeRolesFromUser( "myuser" , [ { role: "readWrite", db: "mydb" } ])

因为在admin数据库创建的，只能在 admin 数据库中登录：

> db.auth("myuser","myuser")
Error: 18 Authentication failed.
0
>
> db
mydb
> use admin
switched to db admin
> db.auth("myuser","myuser");
1
>

此时是可以切换到所在的数据库进行相关操作：

> use mydb
switched to db mydb
>
> db.tab.save({"id":999});
WriteResult({ "nInserted" : 1 })
>
> db.tab.find({"id":999});
{ "_id" : ObjectId("554ef5ac1b590330c00c7d02"), "id" : 999 }
>
> show collections
system.indexes
tab
>

在创建用户时可以在其数据库中创建，这样不用每次都进入admin数据库登录后再切换。如在数据库"mydb"创建用户"userkk"。

use admindb.auth("admin","admin")use mydbdb.createUser({user: "userkk",pwd: "userkk",roles: [ { role: "dbOwner", db: "mydb" } ]}
)db.auth("userkk","userkk")

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华丽分割

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现在授权测试：

#先访问到admin数据库

use admindb.auth("admin","admin")

#切换到 mydb ，在数据库 mydb 中创建角色
#roles: 创建角色"testRole"在数据库 "mydb" 中
#privileges: 该角色可查看"find"数据库"mydb"的所有集合
#db.dropRole("testRole")

use mydbdb.createRole({ role: "testRole",privileges: [{ resource: { db: "mydb", collection: "" }, actions: [ "find" ] }],roles: []
})

#在admin数据库生成集合system.roles。查看角色。

> use admin
switched to db admin
>
> show collections
system.indexes
system.roles
system.users
system.version
>
> db.system.roles.find();
{ "_id" : "mydb.testRole", "role" : "testRole", "db" : "mydb", "privileges" : [ { "resource" : { "db" : "mydb", "collection" : "" }, "actions" : [ "find" ] } ], "roles" : [ ] }
>

#回到mydb，在数据库mydb中创建用户并授予角色"testRole"
#db.dropUser("userkk")

use mydbdb.createUser({user: "userkk",pwd: "userkk",roles: [ { role: "testRole", db: "mydb" } ]}
)

退出mongodb，重新登录进行操作。发现只能使用find
>exit

[root@localhost ~]# mongo
MongoDB shell version: 3.0.2
connecting to: test
> use mydb
switched to db mydb
>
> db.auth("userkk","userkk")
1
>
> db.tab.find({"id":999})
{ "_id" : ObjectId("554ef5ac1b590330c00c7d02"), "id" : 999 }
>
> db.tab.insert({"id":1000})
WriteResult({"writeError" : {"code" : 13,"errmsg" : "not authorized on mydb to execute command { insert: \"tab\", documents: [ { _id: ObjectId('554f145cdf782b42499d80e5'), id: 1000.0 } ], ordered: true }"}
})
>

给角色 "testRole"  添加3个 “Privileges”权限： "update", "insert", "remove"。再重新操作。

use admindb.auth("admin","admin")use mydb#添加Privileges给角色
db.grantPrivilegesToRole("testRole",[{ resource: { db: "mydb", collection: "" },actions: [ "update", "insert", "remove" ]}
])exit #退出mongodb重新登录use mydbdb.auth("userkk","userkk")#增删数据可以操作了！~
db.tab.insert({"id":1000})
db.tab.find({"id":1000})
db.tab.remove({"id":1000})#此时admin的角色记录为：
> db.system.roles.find();
{ "_id" : "mydb.testRole", "role" : "testRole", "db" : "mydb", "privileges" : [ { "resource" : { "db" : "mydb", "collection" : "" }, "actions" : [ "find", "insert", "remove", "update" ] } ], "roles" : [ ] }
>

#更改角色 roles，把roles值全部更新。同样Privileges也可以更新替换！~

use admindb.auth("admin","admin")use mydbdb.updateRole("testRole",{ roles:[{ role: "readWrite",db: "mydb"}]},{ w:"majority" })db.auth("userkk","userkk")show dbs

关于角色，参考官方文档提取总结如下：

参考：mongo Shell Methods  ， Built-In Roles，Security Methods in the mongo Shell