Upgrade 2 Ghost blogs on same server, 1 quits immediately when run as a service

I have 2 Ghost blogs on a Digital Ocean server running:

• Ubuntu 14.04.3 LTS
• Nginx 1.4.6 (Ubuntu)
• Node v0.12.7

I used the instructions provided by Digital Ocean to set up the blogs, and they have worked fine and survived upgrades before.

On Saturday, I upgraded blog #1 from Ghost v0.6.0 to 0.7.0 and experienced no problems. After upgrading I ran service ghost-{blog1} restart and it came online with pomp and triumph.

I immediately attempted to upgrade blog #2 following the same steps, but when I opened it in my browser after restarting the service, I got the “502 Bad Gateway” error.

I found that npm failed to install SQLite3 correctly, and fixed that. Now, I can start the blog successfully by running npm start --production. The terminal shows that Ghost is running and intercepting requests, and I can use the site and blogging app in my browser.

But when I run service ghost-{blog2} start, it continues to fail without presenting a terminal error. I get the following message:

ghost-{blog2} start/running, process 1693

But I still see the “502 Bad Gateway” error in my browser.

<hr>

I changed my startup script to run npm start --production > ghost-{blog2}.log instead of npm start --production, and I can see that Ghost starts up, and then quits immediately without error:

> ghost@0.7.0 start /var/www/{blog2}/ghost
> node index

That’s all that is in the log, even after hitting the page a few times. Nginx logs the requests, but Ghost doesn’t.

By contrast, when I start the blog by running npm start --production > ghost-{blog2}.log from the terminal, the log continues thus:

> ghost@0.7.0 start /var/www/allder.org/ghost
> node index

Migrations: Up to date at version 004
Ghost is running in production...
Your blog is now available on http://allder.org
Ctrl+C to shut down
{{Requests}}

Can anyone suggest steps I can take to troubleshoot this?