在 NestJS 应用中设置环境变量

使用环境变量存储应用程序配置

1npm install @nestjs/config

1import { Module } from '@nestjs/common';
2import { AppController } from './app.controller';
3import { AppService } from './app.service';
4import { BooksModule } from './books/books.module';
5import { TypeOrmModule } from '@nestjs/typeorm';
6import { Book } from './books/entities/book.entity';
7import { Author } from './authors/entities/author.entity';
8import { AuthorsModule } from './authors/authors.module';
9import { ConfigModule } from "@nestjs/config";
10
11@Module({
12  imports: [
13    ConfigModule.forRoot(),
14    TypeOrmModule.forRoot({
15      type: 'postgres',
16      host: 'localhost',
17      port: 5432,
18      username: 'postgres',
19      password: 'pwd123',
20      database: 'book_database',
21      entities: [Book, Author],
22      synchronize: true
23    }),
24    BooksModule,
25    AuthorsModule
26  ],
27  controllers: [AppController],
28  providers: [AppService],
29})
30export class AppModule {}

使用 ConfigService 获取环境变量的值

1import { Module } from '@nestjs/common';
2import { AppController } from './app.controller';
3import { AppService } from './app.service';
4import { BooksModule } from './books/books.module';
5import { TypeOrmModule } from '@nestjs/typeorm';
6import { Book } from './books/entities/book.entity';
7import { Author } from './authors/entities/author.entity';
8import { AuthorsModule } from './authors/authors.module';
9import { ConfigModule } from "@nestjs/config";
10
11@Module({
12  imports: [
13    ConfigModule.forRoot({
14      envFilePath: `.dev.env`,
15    }),
16    TypeOrmModule.forRoot({
17      type: 'postgres',
18      host: 'localhost',
19      port: 5432,
20      username: 'postgres',
21      password: 'pwd123',
22      database: 'book_database',
23      entities: [Book, Author],
24      synchronize: true
25    }),
26    BooksModule,
27    AuthorsModule
28  ],
29  controllers: [AppController],
30  providers: [AppService],
31})
32export class AppModule {}

1import { Module } from '@nestjs/common';
2import { AppController } from './app.controller';
3import { AppService } from './app.service';
4import { BooksModule } from './books/books.module';
5import { TypeOrmModule } from '@nestjs/typeorm';
6import { Book } from './books/entities/book.entity';
7import { Author } from './authors/entities/author.entity';
8import { AuthorsModule } from './authors/authors.module';
9import { ConfigModule } from "@nestjs/config";
10
11@Module({
12  imports: [
13    ConfigModule.forRoot({
14      envFilePath: `.${process.env.NODE_ENV}.env`,
15    }),
16    TypeOrmModule.forRoot({
17      type: 'postgres',
18      host: 'localhost',
19      port: 5432,
20      username: 'postgres',
21      password: 'pwd123',
22      database: 'book_database',
23      entities: [Book, Author],
24      synchronize: true
25    }),
26    BooksModule,
27    AuthorsModule
28  ],
29  controllers: [AppController],
30  providers: [AppService],
31})
32export class AppModule {}

1{
2  "name": "books-api",
3  "version": "0.0.1",
4  "description": "",
5  "author": "",
6  "private": true,
7  "license": "UNLICENSED",
8  "scripts": {
9    "build": "nest build",
10    "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
11    "start": "NODE_ENV=dev nest start",
12    "start:dev": "NODE_ENV=dev nest start --watch",
13    "start:debug": "NODE_ENV=dev nest start --debug --watch",
14    "start:prod": "NODE_ENV=prod node dist/main",
15    "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
16    "test": "NODE_ENV=test jest",
17    "test:watch": "NODE_ENV=test jest --watch",
18    "test:cov": "NODE_ENV=test jest --coverage",
19    "test:debug": "NODE_ENV=test node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
20    "test:e2e": "NODE_ENV=test jest --config ./test/jest-e2e.json"
21  },
22  "dependencies": {
23    "@nestjs/common": "^9.0.0",
24    "@nestjs/core": "^9.0.0",
25    "@nestjs/mapped-types": "^1.2.2",
26    "@nestjs/platform-express": "^9.0.0",
27    "@nestjs/typeorm": "^9.0.1",
28    "class-transformer": "^0.5.1",
29    "class-validator": "^0.14.0",
30    "pg": "^8.11.0",
31    "reflect-metadata": "^0.1.13",
32    "rxjs": "^7.2.0",
33    "typeorm": "^0.3.16"
34  },
35  "devDependencies": {
36    "@nestjs/cli": "^9.0.0",
37    "@nestjs/schematics": "^9.0.0",
38    "@nestjs/testing": "^9.0.0",
39    "@types/express": "^4.17.13",
40    "@types/jest": "29.2.4",
41    "@types/node": "18.11.18",
42    "@types/supertest": "^2.0.11",
43    "@typescript-eslint/eslint-plugin": "^5.0.0",
44    "@typescript-eslint/parser": "^5.0.0",
45    "eslint": "^8.0.1",
46    "eslint-config-prettier": "^8.3.0",
47    "eslint-plugin-prettier": "^4.0.0",
48    "jest": "29.3.1",
49    "prettier": "^2.3.2",
50    "source-map-support": "^0.5.20",
51    "supertest": "^6.1.3",
52    "ts-jest": "29.0.3",
53    "ts-loader": "^9.2.3",
54    "ts-node": "^10.0.0",
55    "tsconfig-paths": "4.1.1",
56    "typescript": "^4.7.4"
57  },
58  "jest": {
59    "moduleFileExtensions": [
60      "js",
61      "json",
62      "ts"
63    ],
64    "rootDir": "src",
65    "testRegex": ".*\\.spec\\.ts$",
66    "transform": {
67      "^.+\\.(t|j)s$": "ts-jest"
68    },
69    "collectCoverageFrom": [
70      "**/*.(t|j)s"
71    ],
72    "coverageDirectory": "../coverage",
73    "testEnvironment": "node"
74  }
75}

1DATABASE_USER=postgres
2DATABASE_PASSWORD=pwd123
3DATABASE_NAME=book_database
4DATABASE_PORT=5432
5DATABASE_HOST=localhost

利用 TypeOrmModule.forRootAsync 通过环境变量和 ConfigService 配置数据库选项

TypeOrmModule.forRootAsync 模块使用配置对象异步初始化 TypeOrmModule。请查看以下配置项：

• imports: [ConfigModule]：将 ConfigModule 导入到 TypeOrmModule.forRootAsync 的配置上下文中，使得 ConfigModule 所导出的提供者（如 ConfigService）可以在该模块的其他部分被注入和使用。

• inject: [ConfigService]：指定将 ConfigService 注入工厂函数中。ConfigService 的作用是提供对 ConfigModule 管理的配置项的访问能力，我们用它来获取具体的数据库配置。

• useFactory: async (configService: ConfigService)：这是一个异步工厂函数，用于创建并返回 TypeORM 模块的配置。该工厂函数会设置必要的参数，并通过 configService 动态获取相应的配置值。