Nodejs gotcha on heroku

Use environment variable process.env.PORT instead of requesting for fixed port. Heroku will assign random port everytime the application bootup. This lead to some misleading error like strange Redis too many connection error and error H10.

app.listen(process.env.PORT || 5000);

Another gotcha when we upgrade the PostgreSQL to the bigger plan, yet another misleading error

error: no pg_hba.conf entry for host 

The paid plan (standard-0) only accept ssl connection:

postgres://user:seckrit@pghost:5432/dbname?ssl=true