I am working on my first NestJS application, which was working fine with hardcoded database connecting string in app.module.ts.
But then as per our requirements, I had to pick the database config values from environment files. For that, I followed the configuration documentation on the nestjs documentation website - https://docs.nestjs.com/techniques/configuration
But the issue is that I need to use the .env variables inside the same file for database connection, which is failing.
Here is my original code that was working fine:
@Module({
imports: [
MongooseModule.forRoot(`mongodb+srv://myusername:mypassword@myhost.net?retryWrites=true&w=majority&db=dbname`, { useNewUrlParser: true, dbName: 'dbname' }),
ProductModule,
CategoryModule,
],
controllers: [
AppController,
HealthCheckController,
],
providers: [AppService, CustomLogger],
})
Now, I wanted to pick those DB values from .env files which are like local.env, dev.env etc. depending on the environment. Now, my this code is not working:
@Module({
imports: [
ConfigModule.forRoot({ envFilePath: `${process.env.NODE_ENV}.env` }),
MongooseModule.forRoot(`mongodb+srv://${ConfigModule.get('DB_USER')}:${ConfigModule.get('DB_PASS')}@myhost.net?retryWrites=true&w=majority&db=dbname`, { useNewUrlParser: true, dbName: 'dbname' }),
ProductModule,
CategoryModule,
],
controllers: [
AppController,
HealthCheckController,
],
providers: [AppService, CustomLogger],
})
MongooseModule.forRootAsync({
imports: [ConfigModule],
useFactory: async (configService: ConfigService) => ({
uri: configService.get<string>('MONGODB_URI'),
}),
inject: [ConfigService],
});
From Nestjs docs here - https://docs.nestjs.com/techniques/configuration
These steps worked for me with MySQL and TypeORM.
Install Nestjs config module - npm i --save @nestjs/config. It relies on dotenv
Create a .env file in your root folder and add your key/value pairs e.g. DATABASE_USER=myusername
Open app.module.ts and import the config module
import { ConfigModule } from '@nestjs/config';
app.module.ts. I added it a the first import. It will load the contents of the .env file automatically. ConfigModule.forRoot(),
process.env.DATABASE_USER
For more configuration of the ConfigModule, see the link above. You can use a custom file/path and set the module visible globally.
You need to use the MongooseModule.forRootAsync(() => {...}) instead of MongooseModule.forRoot(...)
This makes MongooseModule wait for its IOC dependencies.
See: https://docs.nestjs.com/techniques/mongodb#async-configuration
1. Keeping using ConfigModule
You need to set NODE_ENV in npm scripts so that it can be used to load an env file based on the env.
"scripts": {
"start:local": "NODE_ENV=local npm run start"
"start:dev": "NODE_ENV=dev npm run start"
}
Now you can just use the ConfigModule:
@Module({
imports: [
ConfigModule.forRoot({ envFilePath: `${process.env.NODE_ENV}.env` }),
MongooseModule.forRoot(`mongodb+srv://${process.env.DB_USER}:${process.env.DB_PASS}@myhost.net?retryWrites=true&w=majority&db=dbname`, { useNewUrlParser: true, dbName: 'dbname' })
...
})
2. Using dotenv
npm install dotenv
Add some scripts to your package.json to set what env you are in.
"scripts": {
...
"start:local": "NODE_ENV=local npm run start"
"start:dev": "NODE_ENV=dev npm run start"
}
Import dotenv in main.ts file. Make sure you do it at the top of the file.
require('dotenv').config({ path: `../${process.env.NODE_ENV}.env` });
3. Using env-cmd
You can use env-cmd npm package.
npm install env-cmd
And add some commands for different envs in package.json, for example:
"scripts": {
...
"start:local": "env-cmd -f local.env npm run start"
"start:dev": "env-cmd -f dev.env npm run start"
}
...
Now you can use the env variables, for example:
MongooseModule.forRoot(`mongodb+srv://${process.env.DB_USER}:${process.env.DB_PASS}@myhost.net?retryWrites=true&w=majority&db=dbname`, { useNewUrlParser: true, dbName: 'dbname' })
process.env.MONGO_CONNECTION_STRING
By using nestjs/config package:
npm install @nestjs/config
After installing the package, in the app module (app.module.ts file):
import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';
@Module({
imports: [ConfigModule.forRoot()],
})
export class AppModule {}
After that .env files can be accessed all over the app. Suppose your .env file looks like this.
DB_USER=mohit
to access DB_USER variable use process.env.DB_USER