PM2 and Nginx: 502 Bad Gateway

Question

I've been trying to deploy my Node project on a brand new DO droplet, but i'm having some problems with PM2.

My steps are a follows:

Node came installed on the Droplet image (Ubuntu, Node v4.4.4)
Installed PM2 globally
Setup Nginx to reverse proxy 127.0.0.1:3000
Cloned my project and did npm install

All i get is Nginx complaining about a 502 Bad Gateway.

If i look at the Nginx error.log i get this:

connect() failed (111: Connection refused) while connecting to upstream, client: client.ip, server: my.server, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:3000/", host: "my.server"

PM2 doesn't have much to say about anything. Nothing in pm2 logs and status is online.

I tried skipping PM2 and just doing npm start which worked perfectly. I also tried setting up a dummy hello world application instead, and using that with PM2 - it also worked.

So this is currently where i'm at:

My project + PM2: doesn't work.
My project without PM2: works.
Hello World app + PM2: works.

I'm not really sure where to go from here.. I could just skip PM2 and use node, but i do want the features of PM2.

Any ideas?

Well.. it's probably isn't as Nginx is complaining. I just have no idea how i can check. PM2 says that's everything is all good and online and the logs are clean. — Jacob K, May 24 '16 at 10:33
My problem actually turned out to so silly actually, I noticed that 502s were given only for POST requests that do modify the database, which was a sqllite file within the app directory which caused PM2 to restart the app before sending the response when that file was written because it was run with --watch flag. on other cases it can be the --kill-timeout that is too short for you response time, which also causes the app restart. — OsMinOsM, Aug 09 '20 at 06:33

Jacob K · Accepted Answer · 2018-05-08T10:39:40.740

14

I just had to start PM2 with bin/www instead of app.js. Express generator and everything...

edited May 08 '18 at 10:39

answered May 24 '16 at 12:51

Jacob K

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16

Have had an incredibly horrific afternoon trying to solve this problem. Would love to know why bin/www worked while app.js did not. – scoob Sep 09 '16 at 21:37
Thank you. Worked with my MEAN application. – Tom Ford Jul 05 '17 at 15:59
1

Also ensure NODE_ENV=production – Jul 09 '18 at 07:13
what is bin/www and where is it located ? – Peter Moses Nov 23 '20 at 02:29
@PeterMoses and anyone else interested: `bin/www` is relative your application directory. Example: my project is in `/var/www/my-project/`. From `my-project`, I ran `pm2 start node ./bin/www` and my application is now served as expected. – lobsterhands Sep 26 '21 at 16:37
work in 2022!!! – yanir midler May 17 '22 at 10:43

score 0 · Answer 2 · answered Jul 22 '20 at 03:49

0

Nginx has a directive called proxy_read_timeout which defaults to 60 secs. It determines how long nginx will wait to get the response to a request. In nginx. conf file, setting proxy_read_timeout to 120 secs solved our problem.

answered Jul 22 '20 at 03:49

Huáscar Méndez

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score 0 · Answer 3 · answered Feb 09 '22 at 20:38

0

In my case I renamed app.js to project.js or something and it works.

answered Feb 09 '22 at 20:38

Shahriyar

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worked for me too – xxkazunarixx Aug 07 '23 at 02:52

Deepa George · Answer 4 · 2021-07-11T02:43:33.930

-3

This is some issue with the node installation. Delete the node_modules folder, install again using npm and start the project using pm2.

pm2 kill

rm -rf node_modules

npm i

pm2 start bin/www

edited Jul 11 '21 at 02:43

answered Jul 11 '21 at 02:37

Deepa George

1
1

PM2 and Nginx: 502 Bad Gateway

4 Answers4

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