aliceの技術ブログ

技術ブログ

WSL2上のDockerでAPIサーバを構築する(expressとMySQL)

はじめに

DockerでAPIサーバ構築する機会が増えたので、メモ代わりに。

なお、この記事は以下の記事の内容を含みます。

DockerでMySQLとNode.jsを動かす(雑) - aliceの技術ブログ

ハンズオン

WSL2 の インストール

以下のコマンドを実行することで、WSL2をインストールできる。

PS C:\Users\******>wsl --install

詳細は以下 learn.microsoft.com

WSL2 に yarn を入れる

この記事を参照 alice-tech.hatenablog.com

Docker のインストール

以下の記事を参考にDockerをインストールする learn.microsoft.com

WSL上でAPIサーバのディレクトリを作成し、エディタを開く

ディレクトリを作成

mkdir api

作成したディレクトリに移動

cd api

vscode を開く*1

code .

Docker で MySQL のイメージを取得

docker pull mysql

しばらく待つと以下のような表示が出て完了する

docker pull mysql
Using default tag: latest
latest: Pulling from library/mysql
fcbdc4090331: Pull complete
95eb5073c36f: Pull complete
5e5ba0e6412a: Pull complete
ee4654eb29b7: Pull complete
1d2218160b86: Pull complete
bbe712936412: Pull complete
4a6efa152609: Pull complete
0f7c3b67bb2b: Pull complete
7ccd17e83c8a: Pull complete
04bf2c116556: Pull complete
Digest: sha256:4a4e5e2a19aab7a67870588952e8f401e17a330466ecfc55c9acf51196da5bd0
Status: Downloaded newer image for mysql:latest
docker.io/library/mysql:latest

What's Next?
  View a summary of image vulnerabilities and recommendations → docker scout quickview mysql

うまくいかなければ公式ドキュメントを読む hub.docker.com

docker-compose.yml の作成

touch docker-compose.yml
version: "3"

services:
  db:
    image: mysql
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: "password"
      MYSQL_DATABASE: "test"
      MYSQL_USER: "alice"
      MYSQL_PASSWORD: "password"
      TZ: "Asia/Tokyo"
    ports:
      - 13306:3306
    volumes:
      - ./db/init:/docker-entrypoint-initdb.d
      - db-store:/var/lib/mysql
    networks:
      - my-network

  api:
    image: api-image
    container_name: api-sample
    build:
      context: .
    ports:
      - "3000:3000"
    env_file:
      - .env
    volumes:
      - /api/:/app
    networks:
      - my-network
    depends_on:
      - db

volumes:
  db-store:
networks:
  my-network:

express のディレクトリを作る

mkdir express-api

package.json の作成

cd express-api
yarn init
yarn init v1.22.22
question name (express-api): 
question version (1.0.0): 
question description: 
question entry point (index.js): index.ts
question repository url: 
question author: 
question license (MIT): 
question private: 
success Saved package.json
Done in 8.86s.

内容

{
  "name": "api",
  "version": "1.0.0",
  "main": "index.ts",
  "license": "MIT"
}

必要なライブラリをインストール

yarn add express mysql2 node-cron

開発時に使用するライブラリをインストール

yarn add -D typescript ts-node ts-node-dev npm-run-all @types/express @types/node @types/node-cron 

package.json はこのようになる。

{
  "name": "express-api",
  "version": "1.0.0",
  "main": "index.ts",
  "license": "MIT",
  "dependencies": {
    "express": "^4.19.2",
    "mysql2": "^3.9.7",
    "node-cron": "^3.0.3"
  },
  "devDependencies": {
    "@types/express": "^4.17.21",
    "@types/node": "^20.12.11",
    "@types/node-cron": "^3.0.11",
    "npm-run-all": "^4.1.5",
    "ts-node": "^10.9.2",
    "ts-node-dev": "^2.0.0",
    "typescript": "^5.4.5"
  }
}

以下を package.json に追加する

"scripts": {
    "dev": "ts-node-dev --respawn index.ts",
    "tsc": "tsc",
    "build": "npm-run-all clean tsc",
    "start": "node dist/index.js"
}

最終的に以下のようになる。

{
  "name": "express-api",
  "version": "1.0.0",
  "main": "index.ts",
  "license": "MIT",
  "scripts": {
    "dev": "ts-node-dev --respawn index.ts",
    "tsc": "tsc",
    "build": "npm-run-all clean tsc",
    "start": "node dist/index.js"
  },
  "dependencies": {
    "express": "^4.19.2",
    "mysql2": "^3.9.7",
    "node-cron": "^3.0.3"
  },
  "devDependencies": {
    "@types/express": "^4.17.21",
    "@types/node": "^20.12.11",
    "@types/node-cron": "^3.0.11",
    "npm-run-all": "^4.1.5",
    "ts-node": "^10.9.2",
    "ts-node-dev": "^2.0.0",
    "typescript": "^5.4.5"
  }
}

tsconfig.json の作成

npx tsc --init

適当にいじります。不要部分は削除でOK

{
  "compilerOptions": {
    /* Visit https://aka.ms/tsconfig to read more about this file */

    /* Projects */
    // "incremental": true,                              /* Save .tsbuildinfo files to allow for incremental compilation of projects. */
    // "composite": true,                                /* Enable constraints that allow a TypeScript project to be used with project references. */
    // "tsBuildInfoFile": "./.tsbuildinfo",              /* Specify the path to .tsbuildinfo incremental compilation file. */
    // "disableSourceOfProjectReferenceRedirect": true,  /* Disable preferring source files instead of declaration files when referencing composite projects. */
    // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */
    // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */

    /* Language and Environment */
    "target": "es2022",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
    // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
    // "jsx": "preserve",                                /* Specify what JSX code is generated. */
    // "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
    // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
    // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */
    // "jsxFragmentFactory": "",                         /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
    // "jsxImportSource": "",                            /* Specify module specifier used to import the JSX factory functions when using 'jsx: react-jsx*'. */
    // "reactNamespace": "",                             /* Specify the object invoked for 'createElement'. This only applies when targeting 'react' JSX emit. */
    // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
    // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
    // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */

    /* Modules */
    "module": "commonjs",                                /* Specify what module code is generated. */
    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
    "moduleResolution": "node",                     /* Specify how TypeScript looks up a file from a given module specifier. */
    // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
    // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
    // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
    // "typeRoots": [],                                  /* Specify multiple folders that act like './node_modules/@types'. */
    // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
    // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
    // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
    // "resolveJsonModule": true,                        /* Enable importing .json files. */
    // "allowArbitraryExtensions": true,                 /* Enable importing files with any extension, provided a declaration file is present. */
    // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */

    /* JavaScript Support */
    // "allowJs": true,                                  /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
    // "checkJs": true,                                  /* Enable error reporting in type-checked JavaScript files. */
    // "maxNodeModuleJsDepth": 1,                        /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */

    /* Emit */
    // "declaration": true,                              /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
    // "declarationMap": true,                           /* Create sourcemaps for d.ts files. */
    // "emitDeclarationOnly": true,                      /* Only output d.ts files and not JavaScript files. */
    "sourceMap": true,                                /* Create source map files for emitted JavaScript files. */
    // "inlineSourceMap": true,                          /* Include sourcemap files inside the emitted JavaScript. */
    // "outFile": "./",                                  /* Specify a file that bundles all outputs into one JavaScript file. If 'declaration' is true, also designates a file that bundles all .d.ts output. */
    "outDir": "./dist",                                   /* Specify an output folder for all emitted files. */
    // "removeComments": true,                           /* Disable emitting comments. */
    // "noEmit": true,                                   /* Disable emitting files from a compilation. */
    // "importHelpers": true,                            /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
    // "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types. */
    // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
    // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
    // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSources": true,                            /* Include source code in the sourcemaps inside the emitted JavaScript. */
    // "emitBOM": true,                                  /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
    // "newLine": "crlf",                                /* Set the newline character for emitting files. */
    // "stripInternal": true,                            /* Disable emitting declarations that have '@internal' in their JSDoc comments. */
    // "noEmitHelpers": true,                            /* Disable generating custom helper functions like '__extends' in compiled output. */
    // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
    // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
    // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */

    /* Interop Constraints */
    // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
    // "verbatimModuleSyntax": true,                     /* Do not transform or elide any imports or exports not marked as type-only, ensuring they are written in the output file's format based on the 'module' setting. */
    // "allowSyntheticDefaultImports": true,             /* Allow 'import x from y' when a module doesn't have a default export. */
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
    // "preserveSymlinks": true,                         /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */

    /* Type Checking */
    "strict": true,                                      /* Enable all strict type-checking options. */
    // "noImplicitAny": true,                            /* Enable error reporting for expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,                         /* When type checking, take into account 'null' and 'undefined'. */
    // "strictFunctionTypes": true,                      /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
    // "strictBindCallApply": true,                      /* Check that the arguments for 'bind', 'call', and 'apply' methods match the original function. */
    // "strictPropertyInitialization": true,             /* Check for class properties that are declared but not set in the constructor. */
    // "noImplicitThis": true,                           /* Enable error reporting when 'this' is given the type 'any'. */
    // "useUnknownInCatchVariables": true,               /* Default catch clause variables as 'unknown' instead of 'any'. */
    // "alwaysStrict": true,                             /* Ensure 'use strict' is always emitted. */
    // "noUnusedLocals": true,                           /* Enable error reporting when local variables aren't read. */
    // "noUnusedParameters": true,                       /* Raise an error when a function parameter isn't read. */
    // "exactOptionalPropertyTypes": true,               /* Interpret optional property types as written, rather than adding 'undefined'. */
    // "noImplicitReturns": true,                        /* Enable error reporting for codepaths that do not explicitly return in a function. */
    // "noFallthroughCasesInSwitch": true,               /* Enable error reporting for fallthrough cases in switch statements. */
    // "noUncheckedIndexedAccess": true,                 /* Add 'undefined' to a type when accessed using an index. */
    // "noImplicitOverride": true,                       /* Ensure overriding members in derived classes are marked with an override modifier. */
    // "noPropertyAccessFromIndexSignature": true,       /* Enforces using indexed accessors for keys declared using an indexed type. */
    // "allowUnusedLabels": true,                        /* Disable error reporting for unused labels. */
    // "allowUnreachableCode": true,                     /* Disable error reporting for unreachable code. */

    /* Completeness */
    // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  },
  "include": [
    "./**/*"
  ]
}

config.tsindex.ts , db.ts を作成

touch config.ts index.ts db.ts

config.ts

export const config = {
    PORT: Number(process.env.PORT) ?? 3000,
    db: {
        host: process.env.DB_HOST ?? "127.0.0.1",
        port: Number(process.env.DB_PORT) ?? 3306,
        user: process.env.DB_USER ?? "alice",
        password: process.env.DB_PASSWORD ?? "password",
        database: process.env.DB_NAME ?? "test"
    }
};

db.ts

import { createPool, Pool } from "mysql2";
import { config } from "./config";

export const pool: Pool = createPool(config.db);

index.ts

import express from "express";
import { config } from "./config";
import { pool } from "./db";

const app: express.Express = express();
const PORT = config.PORT;

app.use(express.json());
app.use(express.urlencoded({ extended: true }));

app.use((req: express.Request, res: express.Response, next: express.NextFunction) => {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", "*");
    res.header("Access-Control-Allow-Headers", "*");
    next();
});

app.listen(PORT, () => {
    console.log(`start server on port ${PORT}.`)
})

app.get("/test", (async (req: express.Request, res: express.Response) => {
    res.send("Hello, World!");
}));

MySQLの準備をする

api ディレクトリに移動する

cd ../

MySQLの初期化ファイルを置くディレクトリを作成

mkdir -p db/init
touch db/init/create_table.sql

内容

CREATE TABLE IF NOT EXISTS mytable(
    id integer auto_increment not null primary key,
    username text not null
);

.env ファイルを作成

PORT=3000
DB_HOST=db
DB_PORT=3306
DB_USER=alice
DB_PASSWORD=password
DB_NAME=test

MySQLとexpressの接続の準備

Dockerfile を作成する

touch Dockerfile

内容

FROM node
ENV NODE_ENV=dev
WORKDIR /usr/src/app
COPY ./express-api/ .
EXPOSE 3000
CMD [ "yarn", "dev" ]

Dockerをバックグラウンドで起動する 以下のコマンドでビルドもされる

docker-compose up -d

問題なければこのような表示が出て完了する

 ✔ Network api_my-network  Created                                          0.0s 
 ✔ Volume "api_db-store"   Created                                          0.0s 
 ✔ Container api-db-1      Started                                          0.0s 
 ✔ Container api-sample    Started                                          0.0s 

すでにDockerが立ち上がっており、http://localhost:3000/test にアクセスすると、Hello, World! が表示される

また、Docker Desktopの Containers > api > mysql > execmysql -ualice -pを入力すると、mysqlに接続できる

sh-5.1# mysql -ualice -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 8.4.0 MySQL Community Server - GPL

Copyright (c) 2000, 2024, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

また、データベースとテーブルの確認もでき、作成されていることがわかる。

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| performance_schema |
| test               |
+--------------------+
3 rows in set (0.00 sec)

mysql> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| mytable        |
+----------------+
1 row in set (0.00 sec)

Postmanのインストール

APIのテストのため、postman をインストールしておきましょう。 curlなどでも大丈夫ですが、あると便利です。 www.postman.com

MySQLに読み書きするAPIを作成する

APIのエンドポイントは以下の通りです

  • POST /api/v1/users 新規ユーザの作成
  • GET /api/v1/users 登録済みユーザリストの取得

index.ts に追記します

...

app.post("/api/v1/users", (async (req: express.Request, res: express.Response) => {
    await pool.promise().query(
        `insert into mytable set ?`,
        [
            {
                id: new Date().getTime(),
                username: String(req.body.username ?? "Alice"),
            }
        ]
    )
    res.status(201).send();
}));
app.get("/api/v1/users", (async (req: express.Request, res: express.Response) => {
    interface User extends RowDataPacket {
        id: number,
        username: string,
    };
    const [users] = await pool.promise().query<User[]>(
        `select * from mytable`
    );
    res.json(users.map(it => {
        return {
            id: it.id,
            username: it.username,
        }
    }));
}));

docker-composeを再ビルドします。 Docker desktop > Containers から api を削除し、その後 Images の api-images を削除します。 その後下のコマンドを打ちます。

docker-compose up -d

APIからデータの読み書きをする

先ほどインストールしたPostmanで collectionを作ります。

POSTのほうは、以下の画像のように body > rawjson形式でリクエストボディを書きます。

GETリクエストをSend, なにもデータがないため、空配列が返る

POSTリクエストをSend, データが登録された。(レスポンスコード201)

再度、GETリクエストをSend, データが増えている!

おわりに

これで、一通り実装できるようになったかと思います。 長かったですが、慣れればほかの言語やライブラリ使ってもできそうですね。 今回はORM等使ってないですが、組み合わせるとより良いコードになると思います。

*1:好きなエディタでOK