基于golang官方mongo-driver操作总结

有如下json格式字符串，需要使用golang-mongo-driver，操作入库。
(该告警字符串来自WiseAPM告警中心)
写入过程是，将json格式字符串转化为字节类型，使用bson提供的UnmarshalExtJSON方法，构造一个bson.D数据结构，就可以使用Insert系列方法写入mongodb.

{
    "_id" : ObjectId("5fedf5c834879b193cc0a649"),
    "startTime" : NumberLong(1609430455),
    "alertList" : [ 
        {
            "setId" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b",
            "groupId" : "1",
            "time" : NumberLong(1609430455),
            "status" : "alert",
            "setName" : "[ARGUS]ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
            "alertLevel" : "2",
            "source" : "EMP-ALERT-ARGUS-INSTANCE",
            "text" : "[P3 #1/3] pg_cpu_used all(#2) 95.23148>90",
            "tags" : {
                "alertDesc" : "pg_cpu_used",
                "opcmObjType" : "Instance",
                "note" : "",
                "mail_s" : "",
                "alertGrade" : "P3",
                "OS" : "DB_POSTGRESQL_ADMIN",
                "ip" : "",
                "memo" : "",
                "objName" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
                "alertDepartment" : "",
                "entity3" : "pg_cpu_used",
                "mailFormatText" : "【告 警 状  态】告警
【告 警 级  别】P3
【告 警 对  象】ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw
【告   警   IP】
【监   控   项】pg_cpu_used
【监控 项 描述】pg_cpu_used
【标        签】
【备        注】
【表   达   式】all(#2) >90
【接收 人 分组】
【最大告警次数】3
【当前告警次数】1
【事件触发时间】2021-01-01 00:00:55 +0800 GMT-8
",
                "entity1" : "0",
                "maxAlertCount" : "3",
                "mail_c" : "",
                "opcmObjName" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
                "currentAlertCount" : "1",
                "linkUrl" : "",
                "tag" : "",
                "ukey" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b",
                "objType" : "MiddleWare",
                "alertDetailUrl" : "",
                "environment" : "UNKNOW",
                "status" : "UNKNOW"
            },
            "contact" : {},
            "tagSet" : [ 
                {
                    "tagk" : "alertDesc",
                    "tagv" : "pg_cpu_used"
                }, 
                {
                    "tagk" : "note",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "mail_s",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "alertGrade",
                    "tagv" : "P3"
                }, 
                {
                    "tagk" : "OS",
                    "tagv" : "DB_POSTGRESQL_ADMIN"
                }, 
                {
                    "tagk" : "ip",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "memo",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "objName",
                    "tagv" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
                }, 
                {
                    "tagk" : "alertDepartment",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "entity3",
                    "tagv" : "pg_cpu_used"
                }, 
                {
                    "tagk" : "mailFormatText",
                    "tagv" : "【告 警 状  态】告警
【告 警 级  别】P3
【告 警 对  象】ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw
【告   警   IP】
【监   控   项】pg_cpu_used
【监控 项 描述】pg_cpu_used
【标        签】
【备        注】
【表   达   式】all(#2) >90
【接收 人 分组】
【最大告警次数】3
【当前告警次数】1
【事件触发时间】2021-01-01 00:00:55 +0800 GMT-8
"
                }, 
                {
                    "tagk" : "entity1",
                    "tagv" : "0"
                }, 
                {
                    "tagk" : "maxAlertCount",
                    "tagv" : "3"
                }, 
                {
                    "tagk" : "mail_c",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "currentAlertCount",
                    "tagv" : "1"
                }, 
                {
                    "tagk" : "linkUrl",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "tag",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "ukey",
                    "tagv" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b"
                }, 
                {
                    "tagk" : "objType",
                    "tagv" : "MiddleWare"
                }, 
                {
                    "tagk" : "alertDetailUrl",
                    "tagv" : ""
                }, 
                {
                    "tagk" : "opcmObjName",
                    "tagv" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
                }, 
                {
                    "tagk" : "opcmObjType",
                    "tagv" : "Instance"
                }, 
                {
                    "tagk" : "name",
                    "tagv" : "[ARGUS]ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
                }, 
                {
                    "tagk" : "source",
                    "tagv" : "EMP-ALERT-ARGUS-INSTANCE"
                }
            ],
            "alertIdSet" : [],
            "metric" : "pg_cpu_used",
            "lcd" : NumberLong(1609430456889),
            "frequency" : 0.0,
            "isCloseFlag" : "N",
            "anom" : 0.0,
            "step" : 0.0,
            "argusClsoeTime" : 0.0
        }
    ],
    "endTime" : NumberLong(1609430485),
    "preTime" : NumberLong(1606838455),
    "eventName" : "[ARGUS]ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
    "nextTime" : NumberLong(1612022455),
    "tags" : {
        "alertDesc" : "pg_cpu_used",
        "opcmObjType" : "Instance",
        "note" : "",
        "mail_s" : "",
        "alertGrade" : "P3",
        "OS" : "DB_POSTGRESQL_ADMIN",
        "ip" : "",
        "memo" : "",
        "objName" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
        "alertDepartment" : "",
        "entity3" : "pg_cpu_used",
        "mailFormatText" : "【告 警 状  态】告警
【告 警 级  别】P3
【告 警 对  象】ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw
【告   警   IP】
【监   控   项】pg_cpu_used
【监控 项 描述】pg_cpu_used
【标        签】
【备        注】
【表   达   式】all(#2) >90
【接收 人 分组】
【最大告警次数】3
【当前告警次数】1
【事件触发时间】2021-01-01 00:00:55 +0800 GMT-8
",
        "entity1" : "0",
        "maxAlertCount" : "3",
        "mail_c" : "",
        "opcmObjName" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
        "currentAlertCount" : "1",
        "linkUrl" : "",
        "tag" : "",
        "ukey" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b",
        "objType" : "MiddleWare",
        "alertDetailUrl" : "",
        "environment" : "UNKNOW",
        "status" : "UNKNOW"
    },
    "source" : "EMP-ALERT-ARGUS-INSTANCE",
    "toolSource" : null,
    "status" : "关闭",
    "objName" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw",
    "appName" : "",
    "serviceName" : "",
    "subsystemName" : "",
    "buName" : "",
    "group" : null,
    "text" : "[P3 #1/3] pg_cpu_used all(#2) 95.23148>90",
    "lcd" : NumberLong(1609430523522),
    "metric" : "pg_cpu_used",
    "step" : 0.0,
    "department" : "",
    "lastUpdateTime" : NumberLong(1609430523522),
    "lastMergeTime" : NumberLong(1609430472034),
    "mark" : false,
    "setId" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b_1",
    "tagSet" : [ 
        {
            "tagk" : "alertDesc",
            "tagv" : "pg_cpu_used"
        }, 
        {
            "tagk" : "note",
            "tagv" : ""
        }, 
        {
            "tagk" : "mail_s",
            "tagv" : ""
        }, 
        {
            "tagk" : "alertGrade",
            "tagv" : "P3"
        }, 
        {
            "tagk" : "OS",
            "tagv" : "DB_POSTGRESQL_ADMIN"
        }, 
        {
            "tagk" : "ip",
            "tagv" : ""
        }, 
        {
            "tagk" : "memo",
            "tagv" : ""
        }, 
        {
            "tagk" : "objName",
            "tagv" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
        }, 
        {
            "tagk" : "alertDepartment",
            "tagv" : ""
        }, 
        {
            "tagk" : "entity3",
            "tagv" : "pg_cpu_used"
        }, 
        {
            "tagk" : "mailFormatText",
            "tagv" : "【告 警 状  态】告警
【告 警 级  别】P3
【告 警 对  象】ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw
【告   警   IP】
【监   控   项】pg_cpu_used
【监控 项 描述】pg_cpu_used
【标        签】
【备        注】
【表   达   式】all(#2) >90
【接收 人 分组】
【最大告警次数】3
【当前告警次数】1
【事件触发时间】2021-01-01 00:00:55 +0800 GMT-8
"
        }, 
        {
            "tagk" : "entity1",
            "tagv" : "0"
        }, 
        {
            "tagk" : "maxAlertCount",
            "tagv" : "3"
        }, 
        {
            "tagk" : "mail_c",
            "tagv" : ""
        }, 
        {
            "tagk" : "currentAlertCount",
            "tagv" : "1"
        }, 
        {
            "tagk" : "linkUrl",
            "tagv" : ""
        }, 
        {
            "tagk" : "tag",
            "tagv" : ""
        }, 
        {
            "tagk" : "ukey",
            "tagv" : "s_548807257_2972083_56e5d1e6c60d6d4404f83bc61f312c8b"
        }, 
        {
            "tagk" : "objType",
            "tagv" : "MiddleWare"
        }, 
        {
            "tagk" : "alertDetailUrl",
            "tagv" : ""
        }, 
        {
            "tagk" : "opcmObjName",
            "tagv" : "ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
        }, 
        {
            "tagk" : "opcmObjType",
            "tagv" : "Instance"
        }, 
        {
            "tagk" : "name",
            "tagv" : "[ARGUS]ac82b78a-24df-43b7-85c4-6d49b6d6ee98::[DB_PG]SHE_primary_6262_pg6799yw"
        }, 
        {
            "tagk" : "source",
            "tagv" : "EMP-ALERT-ARGUS-INSTANCE"
        }
    ],
    "level" : "2",
    "duration" : 30.0,
    "num" : 1.0,
    "createTime" : NumberLong(1609430472034),
    "isArgus" : 1.0,
    "alertInfo" : null,
    "configType" : null,
    "batchId" : null,
    "eventHandleTime" : 30.0
}

首先，初始化mongodb连接池的代码：

common/mgo.go 
package common
import (
 "context"
 "fmt"
 "log"
 "go.mongodb.org/mongo-driver/mongo"
 "go.mongodb.org/mongo-driver/mongo/options"
)
type MongoDrivers struct {
 Client   *mongo.Client
 Database string
}
type MongoCfg struct {
 Host     string `yaml:"host"`
 Port     int    `yaml:"port"`
 Database string `yaml:"database"`
 User     string `yaml:"user"`
 Password string `yaml:"password"`
}
var mongoClient *mongo.Client
var MgoDbName string
func GetMongoClient() *mongo.Client {
 return mongoClient
}
func GetMongoDB() string {
 return MgoDbName
}
// 初始化
func InitMongoDriver(m *MongoCfg) (err error) {
 //设置客户端参数
 //dsn := fmt.Sprintf("mongodb://%s:%s@%s:%d/%s", m.User, m.Password, m.Host, m.Port, m.Database)
 dsn := fmt.Sprintf("mongodb://%s:%d", m.Host, m.Port)
 clientOptions := options.Client().ApplyURI(dsn).
 SetAuth(options.Credential{
 AuthSource: m.Database,
 Username:   m.User,
 Password:   m.Password,
 })
 //连接到MongoDB
 mongoClient, err = mongo.Connect(context.TODO(), clientOptions)
 //defer client.Disconnect(context.TODO())
 if err != nil {
 log.Fatal(err)
 return
 }
 //检查链接
 err = mongoClient.Ping(context.TODO(), nil)
 if err != nil {
 log.Fatal(err)
 return
 }
 log.Println("[MongoDB] Connected to base MongoDB!")
 return
}
// 关闭
func Close() {
 err := mongoClient.Disconnect(context.TODO())
 if err != nil {
 log.Fatal(err)
 }
 log.Println("Connection to MongoDB closed.")
}

下入过程：
main.go:

import (
 "go.mongodb.org/mongo-driver/bson"
 "go.mongodb.org/mongo-driver/mongo/options"
)
//mongoClient
mongoClient := common.GetMongoClient()
jsonBytes := []byte(jsonString)
var insert_bson_d = bson.D{}
err = bson.UnmarshalExtJSON(jsonBytes, true, &insert_bson_d)
_, err = mongoClient.Database(from_mongodb).Collection(to_collection).InsertOne(context.Background(), insert_bson_d)

同理，如果要将mongodb中复杂的数据结构，读出为json或map[string]interface{}格式，即可进行相反的操作过程（代码片段）：

mongoClient := common.GetMongoClient()
findOptions := options.Find()

findOptions.SetSort(bson.D{{"_id", 1}})
filter := bson.D{{}}

cur, err := mongoClient.Database(from_mongodb).Collection(from_collection).Find(context.Background(), filter, findOptions)
var jsonMaps []map[string]interface{}
for cur.Next(context.Background()) {
 var bsonDoc bson.D
 var tmpBytes []byte
 var jsonMap map[string]interface{}
 err = cur.Decode(&bsonDoc)
 if err != nil {
 log.Fatal(err)
 continue
 }
 tmpBytes, err = bson.MarshalExtJSON(bsonDoc, true, true)
 if err != nil {
 log.Fatal(err)
 continue
 }
 err = json.Unmarshal(tmpBytes, &jsonMap)
 if err != nil {
 log.Fatal(err)
 continue
 }
 jsonMaps = append(jsonMaps, jsonMap)
}