Postgres connection failure when running node app using supervisor - node.js

Question

I have nodejs webapp with postresql. I am running this using supervisord on the server. The problem is that the postgresql login from nodejs is failing. The error message is:
no PostgreSQL user name specified in startup packet
which basically means no user name is being passed from the webapp while connecting to the db.
Note that I am using unix socket for connecting to postgres from my webapp.
My webapp1.conf looks like:
[program:webapp1]
user=webapp1
command = node /home/webapp1/projects/webapp1/app.js
directory = /home/webapp1/projects/webapp1
autostart = true
autorestart = true
stdout_logfile = /var/log/supervisor/webapp1.log
stderr_logfile = /var/log/supervisor/webapp1_err.log
I have confirmed that supervisor is running the webapp is running under user webapp1.
One more thing - if I start my webapp by logging in as user webapp1, it works.

Answer 1

It sounds like you've got your server set up to use password-less logins to PostgreSQL-- i.e. you have local logins in your pg_hba.conf set to peer or trust so that as long as there's a user configured in postgres with the same name as your linux user, you don't have to do any further configuration to get Postgres working in your apps-- it effectively grants access to the db based on your Linux user account.
I had the same problem when running a simple nodejs script via cron. It worked fine from the shell, but complained of missing username when running via cron. Setting the username explicitly in code wasn't an option because I'd built my config to be as automatic as possible-- I needed it to figure out privileges by which user the script was running as.
It turns out that either the connector library or postgres itself infers the username from an environment variable. I was able to fix it by setting USER=<cron user name> at the top of my crontab (since this was set explicitly in the env of an interactive shell, which is why this works at all).
It looks like the proper syntax to add to your webapp1.conf would be:
environment=USER="<user name here>"