Meteor server crashes very frequently without any error - javascript

I am working with the Meteor application and I deployed the same over EC2 instance. It was working fine till a few days back.
But now the server process kill automatically without any error log or
console
I tried to get the error but unfortunately, as there are not any logs I am unable to find out why the server is crashing again and again.
I have a medium EC2 machine on which the application is running.
I am using nohup for running the application in the background.
Below is the command I used to start the server:-
nohup meteor --settings SETTINGS-PRODUCTION.JSON &
I am wondering to know about server crashes due to nohup or some other reason is there.
Please let me know how we can console uncaught exception in the meteor-like we do in express.
What should I use to auto restart the server if the process is killed
by any error or exception?
Any help would be much appreciated!
Thanks

Using nohup is quite a low-tech solution. Things like Phusion Passenger, PM2, or forever do a better job.
Also your docker container can be configured to automatically restart the process.
Even better is a tool called Meteor Up, which makes it really simple to deploy Meteor apps to EC2.
EASILY DEPLOY YOUR APP Meteor Up is a production quality Meteor app
deployment tool.
Install with one command:
$ npm install --global mup
http://meteor-up.com/

Related

How to restart a Node.js project?

I'm not a Node.js developer. So I have no idea how it works. I've been a PHP developer for over 8 years.
Because of some reason, I need to make a small change in a Node.js project which is live. All I have to do is changing a payment gateway token. I did it like this:
After pulling it on the server, users still go to the old payment gateway. So I guess I need to do a restart. (I'm saying so because, for PHP projects, when you change a config-related thing, you need to restart PHP).
Not sure should I restart what thing? Noted that, the server is Ubuntu 20.04 and uses Nginx to talk to Node.js. In other word, how can I see Node is running as what service on Linux?
Also, there are two files that I think I need to run the project again after restarting Node through one of them: index.js, server.js. Am I right?
And
Your Node.js script likely runs under a process that restarts the script in case it dies. There are several "run forever" wrappers, the most popular one is pm2. Find out which one is used in your project. Try pm2 list as the user your project executes under. If pm2 type pm2 restart app_name to restart your project.
Please check if it is a node.js project so you can write the command node index.js or node server.js with this command you can start your node server.

Bot shuts down when putty window is closed

I created a discord bot and am now attempting to run it off an Ubuntu Machine.
I installed the folders of the bot and NodeJs, here is what I used to install NodeJS:
sudo apt-get install -y nodejs
Then I used cd to select the directory, and started my bot using node index.js
The bot started, however when I went to close the putty and keep it running on the VPS the bot shutdown. Here is what the directory looks like.
I think the problem is that when you start the app in the putty window, that process is linked to the window and gets terminated when that is closed.
To avoid that you can use a host service like screen, tmux, nohup, bg and so on...
If you want to know which is the best, try looking at this question from the askUbuntu Stack Exchange.
The key concept is that you open a new window using the tmux command (or screen, ...), then run your bot like you always do. When you want to leave but keep the process runing, you can detach the session with a key combination, that changes from service to service.
If you want to access that window again, you can run a command that will "restore" your session, like
tmux list-sessions
tmux attach-session -t 0
The NodeJS instance is terminated when putty is closed. You need something to keep the instance alive. Try:
PM2: http://pm2.keymetrics.io/
or,
Forever: https://github.com/foreverjs/forever#readme
Recommended though is to run the node instance as a service that can reboot on startup. Try looking at this:
https://stackoverflow.com/a/29042953/7739392
The shell runs in the foreground. This means any scripts you start there will end once you end your session. A simple solution would be to run your script in the background by adding the & after the call:
node index.js &
A better solution would be to create a service you can ask the service daemon to run for you. However, adding the & should get you what you want for now.
I recommend using one of these two node modules - ForeverJS or PM2. I'll show you how to quickly get started with ForeverJS but PM2 would be very similar.
You can easily install ForeverJS by typing the following in your terminal:
$ npm install forever -g
You may need to use SUDO depending on your user's privileges to get this working properly. It is NOT recommended to use it in production due to the security risks.
Once installed CD to your projects file directory and like you typed 'node index.js' you will do something similar with ForeverJS.
$ forever start index.js
Now when you exit the terminal your NodeJS application will remain as a running process.

How to solve "Access-Control-Allow-Origin"-Issue in vue.js?

Im new to vue.js and webpack. I currently have a very big trouble to archive the next step: communicate with real-world-apis in a dev env.
what i currently do is:
npm run dev
my application calls an remote api to which i have no access.
then i run into the Access-Control-Allow-Origin-Issue.
If i build my application and run it with xampp everything works fine.
What can i do, to simply develope my application instead to hassle with that security thing?
I have tried to create a proxy, so i have already looked at:
npm cors (node-cors-client and node-cors-server) - but how does that apply to my vue app?
socket.io - but it seems to be overkill
http-server - but i got the same issues here
nuxt - could work, but then i need to refactor my vue.js app to nuxt and i dont know if this works then
any suggestions? Thanks!
Solved:
I ended up with a PHP-API
The PHP-API runs with xampp under port 80
The Vue.js-App runs with npm dev server under port 8080
The CORS-Hassle must solved then in the PHP-Script with:
https://stackoverflow.com/a/9866124/3918455

Connect to OpenVPN server through Node.js

I’m trying to create a GUI client for connecting to OpenVPN servers using electron and node but I’m struggling to figure out how to actually connect to the servers using the .ovpn files.
My question is what is the best way to connect to an OpenVPN server using node? Would it be best to Tun terminal commands like
“openvpn—config path to config”
Or is there another way applications like tunnelblick do it that might be easier or more efficient?
Hello I have been working with electron and ovpn on my last project, so here are a few tips.
VPNs require admin/root privilege in order to get setup, so running child_process.spawn on openvpn --config <path> will fail unless your electron app is being ran via sudo/admin privilege.
You can also use electron-sudo package, link here. This is basically a child process spawn with sudo/admin. Aka, app runs normally, but vpn command runs with sudo.
However, if your client is sketchy about giving you sudo/admin, the VPN must be ran separately prior to launching your app.
All in all its a admin/sudo thing.
Hope this helps.

How to use a browser on a remote server for an automated tests

I inherited a project where the person wrote tools to test our site's UI using JQuery and JS.
I don't know too much about it other than it requires a browser to be spawned and I think the tool uses JS to interact with iframes to see if it's the expected values.
My job is to get this tool to run on a remote server and post the results to Jenkins.
The remote test server and staging server is linux. From our staging server, I want to write a script to spawn a browser and run cmds from the tool to test our UI. I ran the following manually:
ssh -X user#remote_test_server /usr/bin/firefox
However, the remote server says:
Error: no display specified
Is there a way to spawn a browser for automated testing from one headless server to another? Thanks in advance for your help.
I faced a similar problem when I tried to automate a GUI installation program. While there are quite some different possibilities to choose from (e.g. Xnest, Xephyr?), I ended up using vncserver, because it's relatively easy to debug the GUI session this way.
You need to create a vncpassword file, I think:
mkdir -p $HOME/.vnc
chmod 0700 $HOME/.vnc
echo MyLittlePassword | vncpasswd -f > $HOME/.vnc/passwd
chmod 0600 $HOME/.vnc/passwd
Starting the server is then quite straightforward
vncserver
export DISPLAY=:1
/usr/bin/firefox&
...
Now it is possible to connect to the VNC server with a VNC viewer of your choice. But beware there may be no window manager, depending on the X startup scripts of your environment.
Shutting the server down
vncserver -kill :1
In the configuration of Jenkins project , specify the
Build Environment
Start Xvfb before the build, and shut it down after.
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