When setting up a server, I noticed that the environment variable process.env.PORT is used. Are there any other variables like this? Where can I see all of them?
heroku config
does not show PORT. So, it's incomplete if you need everything. This will create a one-off dyno and show everything.
From here: https://devcenter.heroku.com/articles/getting-started-with-nodejs#console
Run a console in a one-off dyno, then at the > prompt, type "console.log(process.env)":
$ heroku run node
Running `node` attached to terminal... up, run.4778
> console.log(process.env
... )
{ BUILDPACK_URL: 'https://github.com/MichaelJCole/heroku-buildpack-nodejs.git#wintersmith',
TERM: 'xterm',
SENDGRID_USERNAME: 'unicorns@heroku.com',
COLUMNS: '80',
DYNO: 'run.4778',
PATH: '/app/bin:/app/node_modules/.bin:bin:node_modules/.bin:/usr/local/bin:/usr/bin:/bin',
PWD: '/app',
PS1: 'fairydust',
LINES: '22',
SHLVL: '1',
HOME: '/app',
SENDGRID_PASSWORD: 'ponies',
PORT: '52031',
_: '/app/bin/node' }
undefined