How to test, debug and view console log message of Node js app on production server

Question

I have a ubuntu server, on which node js app is running. That app is developed from Sails mvc framework. I am asked to fix some server side js code. But the problem is I don't how to test, and debug those code.

First of all, it's linux server without UI, I can't test from browser by localhost, since the program is triggered from HTTP request.

Secondly, it is also unlikely to debug from build-in debugger command line client, for the same reason as the first one. Maybe I just don't know how...

Third, I saw there is some console.log('...') codes, but I don't know where to find the log file.

Hopefully someone could provide some opinions. Thanks very much.

Answer 1

You don't need the browser - you can do fake requests with curl :

curl -v -XPOST localhost/path -d 'variable=test'

Probbably your app has some logging (logs are saved to a file), so search for it:

• search for the node process PID:

   ps aux | grep node 

  or

   ps aux | grep <your application name> 

• view open files of the node process and find your logs

   ls -l /proc/<node_app_pid>/fd 

Resources:

• List Open Files for Process

Answer 2

Sails has it's own built in test suite, using mocha .

See the Sails documentation on how to test and debug your application.

Answer 3

NodeJS exists outside your browser, as a standalone runtime, so it does not log to your chrome dev console. A node app is started from the terminal using the command node <filename.js> or nodejs <filename.js> . Since you mentioned sails, maybe you are running it as a forever process

To check if you are running it as forever process:

1. Open linux terminal on the server that the app is running on.
2. type forever list
3. Find the entry containing the name of your main file
4. Then get the name of the .log file associated with it
5. To see the logs do tail -f <log file path>