docker-composeでのnode(loopback)とmysqlの疎通エラー

Question

やりたいこと

node(フレームワーク: loopback4)での環境をapp, データベースをdbとしてdocker-composeで構築し疎通したい

現状

docker-compose up時にappがエラーで停止する（ローカルからdbへの接続は確認済み）

エラー内容

Error: connect ECONNREFUSED 127.0.0.1:3306 at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1146:16)

app_1         |   errno: -111,
app_1         |   code: 'ECONNREFUSED',
app_1         |   syscall: 'connect',
app_1         |   address: '127.0.0.1',
app_1         |   port: 3306,
app_1         |   fatal: true

やったこと

• dbとの接続のために指定するhostをdocker-composeのサービス名（db）へ変更
• my.cnfの外部ホストからの接続設定をbind-address=127.0.0.1からbind-address=0.0.0.0へ変更
• デバッグ方法などご教授いただけるととても嬉しいです。

現在のDockerfile, docker-compose.yml

version: "3.8"
volumes:
  mydata:
  db-store:
services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    volumes:
      - type: volume
        source: mydata
        target: /data
        volume:
          nocopy: true
      - type: bind
        source: ./src
        target: /work/src
    environment:
      - DB_CONNECTION=mysql
      - DB_HOST=db
      - DB_PORT=3306
      - DB_DATABASE=${DB_NAME}
      - DB_USERNAME=${DB_USER}
      - DB_PASSWORD=${DB_PASS}
    depends_on:
      - db
      - db-testing
    ports:
      - "3000:3000"
  db:
    image: mysql:8.0
    volumes:
      - db-store:/var/lib/mysql
      - ./logs:/var/log/mysql
      - ./docker/mysql/my.cnf:/etc/mysql/conf.d/my.cnf
    environment:
      - MYSQL_DATABASE=${DB_NAME}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASS}
      - MYSQL_ROOT_PASSWORD=${DB_PASS}
      - TZ=${TZ}
    ports:
      - ${DB_PORT}:3306

  db-testing:
    image: mysql:8.0
    volumes:
      - ./docker/mysql/my.cnf:/etc/mysql/conf.d/my.cnf
    tmpfs:
      - /var/lib/mysql
      - /var/log/mysql
    environment:
      - MYSQL_DATABASE=${DB_NAME}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASS}
      - MYSQL_ROOT_PASSWORD=${DB_PASS}
      - TZ=${TZ}

• dockerfile

# Check out https://hub.docker.com/_/node to select a new base image
FROM node:16-slim

# Set to a non-root built-in user `node`
USER node

# Create app directory (with user `node`)
RUN mkdir -p /home/node/app

WORKDIR /home/node/app

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY --chown=node package*.json ./

RUN npm install

# Bundle app source code
COPY --chown=node . .

RUN npm run build

# Bind to all network interfaces so that it can be mapped to the host OS
ENV HOST=0.0.0.0 PORT=3000

EXPOSE ${PORT}
CMD [ "node", "." ]

mysql起動時に読み込ませるmy.cnf

[client]
default-character-set=utf8mb4

[mysql]
default-character-set=utf8mb4

[mysqldump]
default-character-set=utf8mb4

[mysqld]
character-set-server=utf8mb4
collation-server=utf8mb4_bin
lower_case_table_names=1

# Enable access from the host machine.
bind-address=0.0.0.0

mysqlとの疎通のためにapp側へ入れているライブラリ

"loopback-connector-mysql": "^6.0.2",

• package.json全体

{
  "name": "mysql-tutorial",
  "version": "0.0.1",
  "description": "sample",
  "keywords": [
    "loopback-application",
    "loopback"
  ],
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "engines": {
    "node": ">=10.16"
  },
  "scripts": {
    "build": "lb-tsc",
    "build:watch": "lb-tsc --watch",
    "lint": "yarn run eslint && yarn run prettier:check",
    "lint:fix": "yarn run eslint:fix && yarn run prettier:fix",
    "prettier:cli": "lb-prettier \"**/*.ts\" \"**/*.js\"",
    "prettier:check": "yarn run prettier:cli -l",
    "prettier:fix": "yarn run prettier:cli --write",
    "eslint": "lb-eslint --report-unused-disable-directives .",
    "eslint:fix": "yarn run eslint --fix",
    "pretest": "yarn run rebuild",
    "test": "lb-mocha --allow-console-logs \"dist/__tests__\"",
    "posttest": "yarn run lint",
    "test:dev": "lb-mocha --allow-console-logs dist/__tests__/**/*.js && yarn run posttest",
    "docker:build": "docker build -t mysql-tutorial .",
    "docker:run": "docker run -p 3000:3000 -d mysql-tutorial",
    "premigrate": "yarn run build",
    "migrate": "node ./dist/migrate",
    "preopenapi-spec": "yarn run build",
    "openapi-spec": "node ./dist/openapi-spec",
    "prestart": "yarn run rebuild",
    "start": "node -r source-map-support/register .",
    "clean": "lb-clean dist *.tsbuildinfo .eslintcache",
    "rebuild": "yarn run clean && yarn run build"
  },
  "repository": {
    "type": "git",
    "url": ""
  },
  "author": "yosuke0517 <[e-mail]>",
  "license": "",
  "files": [
    "README.md",
    "dist",
    "src",
    "!*/__tests__"
  ],
  "dependencies": {
    "@loopback/boot": "^3.4.3",
    "@loopback/core": "^2.17.0",
    "@loopback/repository": "^3.7.2",
    "@loopback/rest": "^10.0.1",
    "@loopback/rest-explorer": "^3.3.3",
    "@loopback/service-proxy": "^3.2.3",
    "loopback-connector-mysql": "^6.0.2",
    "tslib": "^2.0.0"
  },
  "devDependencies": {
    "@loopback/build": "^7.0.1",
    "@loopback/eslint-config": "^11.0.1",
    "@loopback/testlab": "^3.4.3",
    "@types/node": "^10.17.60",
    "eslint": "^7.32.0",
    "source-map-support": "^0.5.20",
    "typescript": "~4.3.5"
  }
}

DB接続の設定ファイル（db.datasource.ts)

const config = {
  name: 'db',
  connector: 'mysql',
  url: '',
  host: 'db',
  port: 3306,
  user: 'loopback',
  password: 'password',
  database: 'demo'
};

Comments

[hentaiman]

ログの内容はdb.datasource.tsの設定が使われてないように見えますね
作ったdb.datasource.tsが使われてない可能性はないですか

[sanezane]

ご指摘のおかげで調査が進み、解決しました（自己解決として記載）。大変助かりました！

Answer 1

自己解決

何をやったか

• 1. まず、image,volumeの削除をしてビルドし直し。するとエラーが以下のように変化

Error: connect ECONNREFUSED 192.xxx.xxx.x:3306


app_1         |   errno: -111,
app_1         |   code: 'ECONNREFUSED',
app_1         |   syscall: 'connect',
app_1         |   address: '192.xxx.xxx.x',
app_1         |   port: 3306,
app_1         |   fatal: true

これでホストは合ってそう

• 1. app側の起動を遅らせた

docker-compose.ymlのapp側にentrypoint: "/bin/sh -c 'sleep 10 && node .'"みたいな感じで追加（dbが起動した後にappを起動する的なやり方もあるはず）

上記までやってマイグレーションを試みたら別のエラーが発生

ER_NOT_SUPPORTED_AUTH_MODE: Client does not support authentication protocol requested by server; consider upgrading MySQL client

• MySQL8.0でパスワードの認証形式が変更されているが、Node.jsの「mysql」にはまだ実装されていないようなのでMySQL: 5.7へ変更（コチラの対応をすれば8系でもいけるようだが他にも８系ではダメなことがあると嫌なので５．７にした）

上記対応で一旦疎通完了