Meteor: Debug on server side - debugging

Does anyone know a good method to debug server side code?
I tried enable Node.js debug then use node-inspector but it does not show any of my code.
I end up using console.log but this is very inefficient.
Update: I found the following procedure works on my Linux machine:
When you run Meteor, it will spawn two processes
process1: /usr/lib/meteor/bin/node /usr/lib/meteor/app/meteor/meteor.js
process2: /usr/lib/meteor/bin/node /home/paul/codes/bbtest_code/bbtest02/.meteor/local/build/main.js --keepalive
You need to send kill -s USR1 on process2
Run node-inspector and you can see your server code
On my first try, I modify the last line on meteor startup script in /usr/lib/meteor/bin/meteor to
exec "$DEV_BUNDLE/bin/node" $NODE_DEBUG "$METEOR" "$#"
and run NODE_DEBUG=--debug meteor on command prompt. This only put --debug flag on process1 so I only see meteor files on node-inspector and could not find my code.
Can someone check this on Windows and Mac machine?

In Meteor 0.5.4 this has become a lot easier:
First run the following commands from the terminal:
npm install -g node-inspector
node-inspector &
export NODE_OPTIONS='--debug-brk'
meteor
And then open http://localhost:8080 in your browser to view the node-inspector console.
Update
Since Meteor 1.0 you can just type
meteor debug
which is essentially a shortcut for the above commands, and then launch node inspector in your browser as mentioned.
Update
In Meteor 1.0.2 a console or shell has been added. It may come in handy to output variables and run commands on the server:
meteor shell

Meteor apps are Node.js apps. When running a Meteor app with the meteor [run] command, you can configure the NODE_OPTIONS environment variable to start node in debug mode.
Examples of NODE_OPTIONS environment variable values:
--debug
--debug=47977 - specify a port
--debug-brk - break on the first statement
--debug-brk=5858 - specify a port and break on the first statement
If you export NODE_OPTIONS=--debug, all meteor command run from the same shell will inherit the environment variable. Alternatively, you can enable debugging just for one run, with NODE_OPTIONS="--debug=47977" meteor.
To debug, run node-inspector in a different shell, then go to http://localhost:8080/debug?port=<the port you specified in NODE_OPTIONS>, regardless of what node-inspector tells you to run.

To start node.js in debug mode, I did it this way:
open /usr/lib/meteor/app/meteor/run.js
before
nodeOptions.push(path.join(options.bundlePath, 'main.js'));
add
nodeOptions.push('--debug');
Here are additional practical steps for your to attach debugger eclipse:
use '--debug-brk' instead of '--debug' here, because it's easier for me to attach node.js using eclipse as debugger.
add 'debugger;' in the code where you want to debug.(I prefer this way personally)
run meteor in console
attach to node.js in eclipse(V8 tools, attach to localhost:5858)
run, wait for debugger to be hit
when you start meteor in your meteor app folder, you'll see that "debugger listening on port 5858" in console.

On Meteor 1.0.3.1 (update to Sergey.Simonchik answer)
Start your server with meteor run --debug-port=<port-number>
Point browser to http://localhost:6222/debug?port=<port-number>
Where <port-number> is a port you specify.
In your code add a debugger; where you want to set your break point.
Depending on where debugger; is invoked, it will either break on your client or server browser window with inspector opened.

I like to set breakpoints via a GUI. This way I don't have to remember to remove any debugging code from my app.
This is how I managed to do it server side for my local meteor app:
meteor debug
start your app this way.
Open Chrome to the address it gives you. You MAY need to install https://github.com/node-inspector/node-inspector (it might come bundled with Meteor now? not sure)
You'll see some weird internal meteor code (not the app code you wrote). Press play to run the code. This code simply starts up your server to listen for connections.
Only after you press play you'll see a new directory in your debugger folder structure called "app". In there are your meteor project files. Set a breakpoint in there one the line you want.
Open the local address of your app. This will run your server side code and you you should be able to hit your breakpoint!
Note: you have to reopen the inspector and go through this process again each time your app restarts!

As of Meteor 1.0.2 probably the best way for server-side debugging is directly via the new built-in shell: with running server run meteor shell. More info here: https://www.meteor.com/blog/2014/12/19/meteor-102-meteor-shell

I am not sure why it was not working for you.
I am able to use it by following steps on console (Mac).
$ ps
$ kill -s USR1 *meteor_node_process_id*
$ node-inspector &
Above steps are mentioned on https://github.com/dannycoates/node-inspector. It is for attaching node-inspector to running node process.

I wrote a small meteor package called meteor-inspector which simplifies the use of node-inspector to debug meteor apps. It internally manages the lifecycle of node-inspector and hence, the user does not need to restart the debugger manually after some files have changed.
For more details and concrete usage instructions take a look at https://github.com/broth-eu/meteor-inspector.

for meteor 1.3.5.2, run
meteor debug --debug-port 5858+n
n is a non-zero number, this will cause node-inspector use 8080+n as web port.

WebStorm, the powerful IDE free for open source developers, makes it much easier to debug server-side.
I've tested it on Windows, and the configuration was painless - see my answer.

A inspector that solve my issues is meteor server console. Here is the process I followed to install it:
In your project folder, add the smart package server-eval:
mrt add server-eval
For Meteor 1.0:
meteor add gandev:server-eval
Restart meteor.
Download crx Chrome extension file from here.
Open extensions page in Chrome and drag crx file to extensions page.
Restart Chrome.
Check the web inspector out to eval server side code:
In comparison with node-inspector, I have a clearer output.

If you prefer to use nodeJS' official debugger you can call NODE_OPTIONS='--debug' meteor and then (on a different shell) node debug localhost:5858.

Related

Debug jHipster application

I'm new to jHipster, I've created APIs which are consumed by my application's front end. I want to debug my services but unable to attach debugger with IntelliJ.
My application starts by running command "mvnw" which is jHispter standard command when I opened this bat file in editor i found this :
#REM e.g. to debug Maven itself, use
#REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
I setup MAVEN_OPTS environment variable but still it was of no use. I also tried to make a remote connection from IDE on port 8000 but still, it didn't serve a purpose.
Any help will be appreciated, thanks.
you can just run (in debug mode) the main method in the JhipApp Class (the SpringBootApplication Class). It worked for me
My tested and proven solution for debugging and then dividing the front end with the back ends, works for OS Windows and Ubuntu with the use of the latest version of the Ide Intellij Community (2020.1.1 used in both OS), provides that after creating a jhipster app (created with Ubuntu), from the command promp or from the Ubuntu shell launch the command: mvn -DskipTests = true clean install to compile the back end first and then the front end (in Angular 8 in my case), at the end of this compilation run the following command: mvn spring-boot: run.
After launching the application, click Ctrl + C and stop the run. Now you can launch the npm commands and then the command: npm start from the same command prompt or from the shell, since your project has been built and already launched it will be restarted and now from the Ide you can launch your class configuration annotated with #SpringBootApplication from the debug icon, at the end of the compilation you will have front ends and back ends divided and debuggable easily as well as hot changes for the front end take place quickly, while for the back end you will always have to save recompile and restart in debug.
You can do it, if you connect remotely, as you suggested in your question
Start jhipster in the terminal, but pass in some debug params
$ ./mvnw -Dspring-boot.run.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"
Then you just connect to it using your IDE at port 5005.
For example, in Visual Studio Code
add a "launch.json" file
A "Add Configuration" button will be displayed when you have the launch.json as the active file in the editor. Click it.
Choose "Java: Attach by Process Id"
That will add a new configuration to the "Run and Debug" tab.
Click the "Attach by Process ID", button, and choose your process (port 5005 in this example)
Debugging will begin!

Flask debugger not appearing in browser

I'm trying to use the flash debugger, where I made a mistake on purpose to test out the debugger. Whenever the error is shown it is only shown in the terminal, and I can't access the localhost to test it.
I have
app.debug = True
But it only shows the stack trace in the terminal when I run.
flask run
when I run
python routes.py
I see the line where the error happened.
But how can I see the interactive debugger in the browser window?
Try setting the environment variable FLASK_ENV=development
This seems to be the suggested way to enable interactive debugging and other nice to have development features when using the flask run command.
Alternatively you can set FLASK_DEBUG=1 to just enable the interactive debugger

Nightwatch starts selenium and then hangs indefinitely

I'm running a simple nightwatch test on a Windows 10.1 machine. The tests starts up selenium server (e.g., selenium server... started - PID: 12784), but it never gets to the test code. I can use a browser to get to the localhost server page that is spawned from the "node nightwatch.js -t test.js" command, so I know the server is working properly. I've also tried running nightwatch with different browsers, e.g., -e chrome, firefox, IE, and phantomjs, and none of them work. Putting --verbose on the command doesn't provide any more console spew, so not sure how to debug this. I'm running with selenium-server-standalone v2.53.0.
Any suggestions?
Solved my own problem. Turns out the problem was with incompatible versions of node, nightwatch, and python. I figured it out by creating a totally separate clone of my repository and reinstalling all the node/nightwatch/selenium dependencies. Would be nice if there was a debug feature that could be enabled to indicate more details about where a node or nightwatch application is during application startup. I learned of node-inspector, so I'll check it out as a possible debug tool.

Debug meteorjs application with node-inspector

I am trying to debug a meteor application at server side.
I created an environment variable export NODE_OPTIONS='--debug'.
I run meteor (version 0.7.0.1) command. It tells the debugger listening on port 5858.
I start node-inspector (version v0.7.0-2) and point to 127.0.0.1:8080/debug?port=5858, but I can see only a couple of strings, Source, Console and a prompt > where I cannot write anything.
I have this error in the console:
“The connection to ws//127.0.0.1:8080/socket.io/1/websocket/Za… was interrupted while the page was loading”.
The same if I use 0.0.0.0:8080: I can see something more of the debugger on the right panel, as Watch expression, Call stack, but the Source list is still empty.
Node-inspector should be listening, because if I stop meteor says that the remote debugging has been terminated. I cannot figure out what I am doing wrong.
have a look at https://groups.google.com/forum/#!topic/meteor-talk/EG8pe7pF3f8
Just want to share some of my experience on using node-inspector to
debug server side codes:
1. When you run Meteor, it will spawn two processes on Linux machine
(Note: I have not checked this on Windows or Mac machine)
process1: /usr/lib/meteor/bin/node /usr/lib/meteor/app/meteor/
meteor.js
process2: /usr/lib/meteor/bin/node /home/paul/codes/bbtest_code/
bbtest02/.meteor/local/build/main.js --keepalive
You need to send kill -s USR1 on process2
Run node-inspector and you can see your server code
On my first try, I modify the last line on meteor startup script in /
usr/lib/meteor/bin/meteor to
exec "$DEV_BUNDLE/bin/node" $NODE_DEBUG "$METEOR" "$#"
and run NODE_DEBUG=--debug meteor on command prompt. This only put --
debug flag on process1 so I only see meteor files on node-inspector
and could not find my code.
Any suggestion on how to modify the script so we can use "--debug"
flag on the meteor script?
Cheers,
Paul

debugging a uwsgi python application using pycharm

Is it possible to debug a uwsgi application using an ide like PyCharm? I can debug flask based apps fine by running them directly from pycharm but cannot even run a uwsgi app from within pycharm.
Do I have to use remote debugging? Is it possible to start a uwsgi app from within pycharm using run?
You can still run your WSGI app outside of uWSGI for development and debugging purposes.
However sometimes this is not possible, for example if your app relies on uWSGI API features.
As far as I know you can't use "Attach to Process" from PyCharm because your WSGI app is running embedded into uWSGI, and there are no visible Python processes. Remote debugging however works like a charm.
Locate pycharm-debug*.egg files in your PyCharm distribution. For example, on OSX both can be found in /Applications/PyCharm.app/Contents
Copy pycharm-debug-py3k.egg next to your Flask app, or copy pycharm-debug.egg instead if you are using Python 2.7
In PyCharm, create a "Python Remote Debug" configuration from "Run/Debug Configurations" dialog. In this example I use localhost and port 4444. This dialog will show you the corresponding pydevd.settrace(...) line.
Add the following code to your app :
import sys
sys.path.append('pycharm-debug-py3k.egg') # replace by pycharm-debug.egg for Python 2.7
import pydevd
# the following line can be copied from "Run/Debug Configurations" dialog
pydevd.settrace('localhost', port=4444, stdoutToServer=True, stderrToServer=True)
In PyCharm, start the remote debugging session. PyCharm's console should display the following line :
Waiting for process connection...
Run your app from uWSGI as usual. It should attach to the debugger, and PyCharm's console should display :
Connected to pydev debugger (build 139.711)
Your app should break on the pydevd.settrace(...) line. You can then continue and use PyCharm debugger as usual (breakpoints and so on)
Not sure how to interpret your question, as you are mixing apples and oranges. Flask is a framework, uWSGI is an application server. I'll try to answer, though.
As far as I know, uWSGI is not pure python, so debugging it in PyCharm will not be trivial, if even it is possible.
However, since you are using uWSGI to run your application, I'm assuming it complies with the WSGI protocol. In that case, for debugging purposes, you can alternatively run it from a simple pure-python application engine like wsgiref.simple_server.WSGIServer.
There is now an official guide on how to do this:
https://www.jetbrains.com/help/pycharm/remote-debugging-with-product.html#
If your code already exists in remote, you only need to follow Create a run/debug configuration
You'll need the IP where the PyCharm is running. When you run the remote debugger from PyCharm, it'll create a debugging server. Your code will connect to this server.
In my case, I'm using Vagrant, with private IP of the guest 192.168.0.3, and the host's private IP is 192.168.0.1.
My code in the remote guests will connect to the debugging server through the host IP. So I need to use my host IP in the code that I want to debug.

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