What environment variables should we use for database configuration?

[ri8ika]

After following medium blog, I set the following variables:

DATABASE_URL
DB_DATABASE
DB_HOST
DB_PASSWORD
DB_PORT
DB_USER

But this is not working.

After some research I found this issue:

strongloop/loopback-boot#4

But I am still not sure what database environment variables are available to use in loopback 4.

---

For further information, I have used the followings inside application.ts inside the constructor:

this.bind('datasources.config.db').to({
      name: 'postgres',
      connector: 'postgres',
      hostname: process.env.DB_HOST,
      port: process.env.DB_PORT,
      user: process.env.DB_USER,
      password: process.env.DB_PASSWORD,
      database: process.env.DB_DATABASE,
    });
    this.bind('datasources.db').toClass(PostgresDataSource);

I think this is not getting bound, because when try to run migrate on heroku, I get the following error:

Connection fails: Error: connect ECONNREFUSED 127.0.0.1:5432

[dhmlau]

@ri8ika , I think the error occurred because the IP is not correct. I haven't tried it on Heroku but I think you need to modify the index.js. Please see https://loopback.io/doc/en/lb4/deploying_to_ibm_cloud_kubernetes.html#step-2-modify-deploy-testindexjs.

[dhmlau]

I'm transferring your issue to loopback-next repo. That's where it should be anyway.

[dhmlau]

You might also wanna see:
#2176

Hope it helps.

[ri8ika]

Hmm, I'm still getting the error even after using Procfile to run index.js when I try to migrate:

Error: connect ECONNREFUSED 127.0.0.1:5432

I also tried setting up url which was missing, but it still didn't help me.

[dhmlau]

Sorry, i misunderstood your issue and it's actually complaining about cannot connect to the Postgresql. Looking at the code snippet in the original comment, should hostname be host instead? It's because in the datasource.json, it's in the form of:

{
  "name": "ds",
  "connector": "postgresql",
  "url": "",
  "host": "localhost", <---- HERE
  "port": 5432,
  "user": "root",
  "password": "pass",
  "database": "testdb"
}

[ri8ika]

Good catch. But I'm still having same issue.

[dhmlau]

@ri8ika, one last thing I can think of. In this tutorial https://loopback.io/doc/en/lb4/Deploying-to-IBM-Cloud.html#updating-application, it binds the new value in src/index.ts:

app.bind('datasources.config.db').to(updatedDatasourceDb);

I'm not sure what's the difference between setting it here vs in application.ts, perhaps @hacksparrow might be able to answer.
There are users in the above mentioned issue who were able to deploy to Heroku, they might have some more insight.

[ri8ika]

Still no luck.

[dhmlau]

@ri8ika, I wasn't able to reproduce this issue. Since this issue was opened more than a year ago, I'd like to close this issue as non-reproducible. If you still encounter this issue, please feel free to ping here or open a new issue. Thanks.