MongoDB replica set 사용하기(with Docker Compose, Haproxy load balancer)

MongoDB replica set 사용하기(with Docker Compose, Haproxy load balancer)

MongoDB replica set

MongoDB replica set  설명

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production 환경을 위해

mongodb replica set을 사용합니다.

 

MongoDB replica set  사용 방법

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0. 환경 확인

저는 window 10 환경입니다.

일반적으로는 linux 계열의 OS에서 하시는 것을 추천합니다.

(윈도우는 LF나 권한 및 소유 문제 등이 발생합니다.)

 

 

1. docker desktop을 설치

Install Docker Desktop on Windows

 

 

2. docker-compose.yml 작성

# Use root/example as user/password credentials
version: "3.8"

services:
  mongo1:
    image: mongo
    container_name: mongo1
    restart: always
    ports:
      - "4001:27017"
    environment:
      - .env
    volumes:
      - ./mongo1:/data/db
      - ./key:/key
      - ./mongodb.conf:/etc/mongodb.conf
    networks:
      - mongo-net
    command: mongod --config /etc/mongodb.conf

  mongo2:
    image: mongo
    container_name: mongo2
    restart: always
    ports:
      - "4002:27017"
    environment:
      - .env
    volumes:
      - ./mongo2:/data/db
      - ./key:/key
      - ./mongodb.conf:/etc/mongodb.conf
    networks:
      - mongo-net
    command: mongod --config /etc/mongodb.conf

  mongo3:
    image: mongo
    container_name: mongo3
    restart: always
    ports:
      - "4003:27017"
    environment:
      - .env
    volumes:
      - ./mongo3:/data/db
      - ./key:/key
      - ./mongodb.conf:/etc/mongodb.conf
      - ./haproxy.cfg:/etc/haproxy.cfg
    networks:
      - mongo-net
    command: mongod --config /etc/mongodb.conf

  haproxy:
    image: haproxy:2.4
    restart: always
    container_name: haproxy
    ports:
      - 3015:27017
    volumes:
      - ./haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
    networks:
      - mongo-net

networks:
  mongo-net:
    driver: bridge

 

 

3. mongodb key file 생성

mkdir key
cd key
openssl rand -base64 756 > mongodb.key

만약 window라면 추후 에러가 날 수 있으니 다음 포스팅을 참조하시길 바랍니다.

mongod --keyFile 시 permissions on /etc/mongodb.key are too open 또는 /etc/mongodb.key: bad file

 

4. .env 작성

MONGO_HOST=0.0.0.0
MONGO_PORT=27017
MONGO_INITDB_ROOT_USERNAME=root
MONGO_INITDB_ROOT_PASSWORD=password # 본인이 원하는 비밀번호로 대체
MONGO_INITDB_DATABASE=koj

 

5. mongodb.conf 작성

systemLog:
  destination: file
  path: "/var/log/mongodb/mongod.log"
  logAppend: true

storage:
  dbPath: "/data/db"

net:
  port: 27017
  bindIp: "0.0.0.0"

replication:
  replSetName: "rs0"

security:
  keyFile: "/key/mongodb.key"
  authorization: "enabled"

 

 

6. haproxy.cfg 작성

global
  daemon
  maxconn 256

defaults
  mode http
  timeout connect 5000ms
  timeout client 50000ms
  timeout server 50000ms

frontend mongo_frontend
  bind *:27017
  mode tcp
  option tcplog
  default_backend mongo_backend

backend mongo_backend
  mode tcp
  balance roundrobin
  server mongo1 mongo1:27017 check
  server mongo2 mongo2:27017 check
  server mongo3 mongo3:27017 check

윈도우라면 LF 관련 문제가 있으니 따로 도커를 따서 작성하시기 바랍니다.

 

 

7. docker compose up -d

docker compose up -d

 

 

8. mongodb replica set init

docker exec -it mongo1 /bin/bash
mongosh
use admin
db.runCommand({replSetInitiate:{_id:"rs0",members:[{_id:0,host:"mongo1:27017"},{_id:1,host:"mongo2:27017"},{_id:2,host:"mongo3:27017"}]}})
db.createUser(
  {
    user: "root",
    pwd: "password",
    roles: [ { role: "root", db: "admin" } ]
  }
)
db.auth("root","password")
db.createUser({user:"myUser",pwd:"myPassword",roles:[{role:"readWrite",db:"myDB"}]})

 

MongoServerError: Authentication failed.

 

 

9. docker compose down && docker compose up -d

docker compose down
docker compose up -d

 

MongoDB replica set 결과

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로그 파일을 통해 정상적으로 haproxy load balancer, mongodb replica set이 동작함을 알 수 있습니다.

haproxy load balancer log

 

 

 

또한 이를 node에서 mongoose.connect를 통해 로그밸런서를 통해 db에 접근할 수 있음을 확인할 수 있습니다.

external node mongoose connect log

 

readPreference 설정도 해야한다.

MongoDB Compass Secondary node가 비었을 때

 

참조

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MongoDB Documentation

HAProxy - The Reliable, High Perf. TCP/HTTP Load Balancer

Docker Compose overview