authorization of mongoDB3.4

序

如果在程序中，要带口令访问mongoDB, 需要设置mongoDB的授权参数，建立用户等操作。
看到人家已经做好了这个实验, 自己也验证了一下。
发现了一个小坑，/etc/mongod.conf中是新语法，是有层级的，下一个层级的内容开始位置不要用\t，而是2个空格才生效。刚装完的mongoDB3.4的mongod.conf中有些例子，才知道要用2个空格代替\t.

虽然旧语法也能用在mongod.conf中，也好使。但是为了避免未知坑，还是用新语法。
要跟着官方文裆，测试用例，示例走，才能少入坑。

实验

设置mongodb3.4的授权

对应的mongo-cxx-driver版本为3.1.1

> use admin
switched to db admin

> db.createUser({ user: "admin", pwd: "adminpassword", roles: [{ role: "userAdminAnyDatabase", db: "admin" }] })
Successfully added user: {
    "user" : "admin",
    "roles" : [
        {
            "role" : "userAdminAnyDatabase",
            "db" : "admin"
        }
    ]
}

> db.auth("admin", "adminpassword")
1

> exit
bye

sudo vi /etc/mongod.conf
add code below after #security:

// authorization前面是2个空格, 不能是\t
#security:
security:
  authorization: enabled

# not below, don't table key, need 2 space
#security:
#   authorization: enabled

sudo service mongod restart
now mongod error, not start
if mongod was run, info below

sudo service mongod status
[ ok ] Checking status of database: mongod running.


sudo service mongod status
[FAIL] Checking status of database: mongod apparently not running failed!

///////////////////////////////////////
back to mongo

> use admin
switched to db admin

> db.auth("admin", "adminpassword")
1

> use test
switched to db test

> db.createUser({ user: "test_usr", pwd: "test_pwd", roles: [{ role: "dbOwner", db: "test" }] })
Successfully added user: {
    "user" : "test_usr",
    "roles" : [
        {
            "role" : "dbOwner",
            "db" : "test"
        }
    ]
}

> db.auth("test_usr", "test_pwd")
1

> show collections
fs.chunks
fs.files

// the author uri is below
mongodb://youruser:yourpassword@localhost/yourdatabase
mongodb://test_usr:test_pwd@localhost/test

写测试程序进行带口令登录验证

只有增删改查时，才会用到用户登录后的权限。
如果不带口令登录，不是一上来就报错，而是要增删改查时，才抛未登录异常。

bool class_mongo_opt::test()
{
    bool b_rc = false;
    std::string errmsg;
    int i_bp_index = 0;

    printf(">> class_mongo_opt::test() v1.0.0.1\n");
    try {
        // https://docs.mongodb.com/master/reference/connection-string/
        // mongodb://192.168.2.60:27017
        // mongodb://test_usr:test_pwd@localhost/test


        // mongocxx::exception& ex = not authorized on test to execute command { aggregate: "restaurants", pipeline: [ { $group: { _id: "$borough", count: { $sum: 1 } } } ], cursor: {} }: generic server error

        printf("bp = %d\n", i_bp_index++);
        mongocxx::instance inst{}; // This should be done only once.
        printf("bp = %d\n", i_bp_index++);

        // 无认证的写法
        mongocxx::client conn{mongocxx::uri{}};

        // 有认证的写法
        /*
        mongocxx::uri uri("mongodb://test_usr:test_pwd@localhost:27017/test");
        mongocxx::client conn(uri);
        */

        printf("bp = %d\n", i_bp_index++);
        auto db = conn["test"];

        // Group documents by field and calculate count.
        {
            // @begin: cpp-group-documents-by-a-field-and-calculate-count
            printf("1 bp = %d\n", i_bp_index++);
            mongocxx::pipeline stages;
            printf("bp = %d\n", i_bp_index++);
            bsoncxx::builder::stream::document group_stage;

            printf("bp = %d\n", i_bp_index++);
            group_stage << "_id"
                        << "$borough"
                        << "count" << open_document << "$sum" << 1 << close_document;

            printf("bp = %d\n", i_bp_index++);
            stages.group(group_stage.view());

            printf("bp = %d\n", i_bp_index++);
            auto cursor = db["restaurants"].aggregate(stages);

            printf("8 bp = %d\n", i_bp_index++);
            // mongocxx::exception& ex = not authorized on test to execute command { aggregate: "restaurants", pipeline: [ { $group: { _id: "$borough", count: { $sum: 1 } } } ], cursor: {} }: generic server error
            // cursor 遍历时，需要登录数据库后才有权限
            for (auto&& doc : cursor) {
                printf("10 bp = %d\n", i_bp_index++);
                std::cout << bsoncxx::to_json(doc) << std::endl;
            }
            // @end: cpp-group-documents-by-a-field-and-calculate-count
        printf("9 bp = %d\n", i_bp_index++);
        }

        // Filter and group documents.
        {
            // @begin: cpp-filter-and-group-documents
            printf("3 bp = %d\n", i_bp_index++);
            mongocxx::pipeline stages;
            printf("bp = %d\n", i_bp_index++);
            bsoncxx::builder::stream::document match_stage, group_stage;

            printf("bp = %d\n", i_bp_index++);
            match_stage << "borough"
                        << "Queens"
                        << "cuisine"
                        << "Brazilian";

            printf("bp = %d\n", i_bp_index++);
            group_stage << "_id"
                        << "$address.zipcode"
                        << "count" << open_document << "$sum" << 1 << close_document;

            printf("bp = %d\n", i_bp_index++);
            stages.match(match_stage.view()).group(group_stage.view());

            printf("bp = %d\n", i_bp_index++);
            auto cursor = db["restaurants"].aggregate(stages);

            printf("bp = %d\n", i_bp_index++);
            for (auto&& doc : cursor) {
                printf("bp = %d\n", i_bp_index++);
                std::cout << bsoncxx::to_json(doc) << std::endl;
            }
            // @end: cpp-filter-and-group-documents
        printf("4 bp = %d\n", i_bp_index++);
        }

        b_rc = true;
    }
    /*
    catch(mongocxx::exception& ex) {
        printf("mongocxx::exception& ex = %s\n", ex.what());
        b_rc = false;
    }
    */

    catch(std::exception& ex) {
        errmsg = ex.what();
        printf("exception : %s\n", errmsg.c_str());
        b_rc = false;       
    }

    catch(...) {
        printf("catch...\n");
        b_rc = false;       
    }
    return b_rc;
}