In a previous question i asked about how to run index.js at an specific time, at first I thought all my project files would go to the web host, but i was told the index.js should be run on a server.
I googled and found it. i installed node-schedule, i wrapped my async puppeteer in a function then set schedule.scheduleJob( '44 02 * * *', myFunction) and put my index.html with js/css on a xampp and used ngrok. all right, im very happy my app is live.
now i need to know if i have to leave my prompt live so the scheduler will run always.
i mean, is there a better way to do it?
You have a few options:
systemd timers (.timer files), a modern version of cron / at
cron jobs (for repeated jobs)
at jobs (for once-off jobs)
screen. SSH into the host, run screen, run your command (node index.js), press Ctrl D to disconnect. You can then log out of the host and the command keeps running. Log back in and run screen -r to reconnect and see the output of the command.
I want to run a node application from my raspberry pi. The application is supposed to start on boot.
I have included the following lines in /etc/rc.local (before exit 0) :
cd /home/pi/PPBot
node bot.js > dev/null &
I first navigate to the correct folder and then run the bot from there. However the node application is not running when I reboot my raspberry pi. So it seems that rc.local is not executed or unable to execute the lines I provided.
I am looking for a solution so that the application will run at boot.
save this
[Unit]
Description=Node JS Script Service
After=network.target
[Service]
Type=simple
ExecStart=/usr/bin/node /path/to/hello_env.js
Restart=on-failure
[Install]
WantedBy=multi-user.target
to /etc/systemd/system/ as nodescript.service
sudo systemctl daemon-reload
sudo systemctl start nodescript
if it worked, make it startup on boot
sudo systemctl enable nodescript
The examples I 've seen (like this one) used
cd /home/pi/PPBot
node bot.js < dev/null &
instead of
cd /home/pi/PPBot
node bot.js > dev/null &
Note the < instead of the >. As you can see here, the < redirects the Standard In (stdin), while the > redirects the Standard Output (stdout). And as described here,
< /dev/null is used to instantly send EOF to the program, so that it doesn't wait for input (/dev/null, the null device, is a special file that discards all data written to it, but reports that the write operation succeeded, and provides no data to any process that reads from it, yielding EOF immediately). & is a special type of command separator used to background the preceding process.
Since you havent used < dev/null, maybe your program is stuck and waits for some input. The & at the end makes your program run in the background. Try to not include it and see if your Rasberry Pi is still booting. If not, you know that your programs runs continously and blocks further booting; when you used the & sign, your program just failed in a separate process. In this case changing the > to < should help because your programs doesn't wait for input.
If the above doesn't work, update your question with the specific error message. You can view the boot log by using the command dmesg (display message).
In this case when you
cd /home/pi/PPBot
you are no longer in the root directory so when you run
node bot.js > dev/null &
it is looking for the dev folder at /home/pi/PPBot/dev
You will need to add a leading / to ensure it is accessing /dev
change
node bot.js > dev/null &
to
node bot.js > /dev/null &
I'm trying to run this Node script on a couple of Raspberry Pis. It runs smoothly on the Pi3 but on a Pi Zero I get this error:
thread '<unnamed>' panicked at 'destination and source slices have different lengths', libcore/slice/mod.rs:695:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.
I tried to run with RUST_BACKTRACE=1 node script.js but the error output is the same.
I've searched for hours how to run with RUST_BACKTRACE=1 to get some debug information but I find only discussions where is not specified how to use the command.
Both Raspberry boards have the last Raspbian Lite version installed and on the Pi Zero I have a fresh installation.
When I start my server with node app.js in the command line (using Git Bash), I can stop it using ctrl + C.
In my package.json file i got this start-script that allows me to use the command npm start to start the server:
"scripts": {
"start": "node app"
},
When I do this, the server starts as normal:
$ npm start
> nodekb#1.0.0 start C:\Projects\nodekb
> node app.js
Server started on port 3000...
But when i ctrl + C now, the server does not get stopped (the node process still remains in task manager). This means that I get an error when I try to do npm start again, because port 3000 is still being used.
I'm following a tutorial on youtube (video with timestamp), and when this guy ctrl + C and then runs npm start again, it works as normal.
Any ideas why my server process is not stopped when I use ctrl + C?
My app.js file if needed:
var express = require("express");
var path = require("path");
//Init app
var app = express();
//Load View Engine
app.set("views", path.join(__dirname, "views"));
app.set("view engine", "pug");
//Home Route
app.get("/", function(req, res) {
res.render("index", {
title: "Hello"
});
});
//Add route
app.get("/articles/add", function (req, res) {
res.render("add_article", {
title: "Add Article"
});
});
//Start server
app.listen(3000, function() {
console.log("Server started on port 3000...");
});
Thanks!
Ctrl + C does not kill the server. The resolution to the issue was using following code snippet in server.js:
process.on('SIGINT', function() {
console.log( "\nGracefully shutting down from SIGINT (Ctrl-C)" );
// some other closing procedures go here
process.exit(0);
});
This worked for me.
You can also check for other solutions mentioned at Graceful shutdown in NodeJS
I tried it on normal windows cmd, and it worked as it should there. Looks like it's a problem with git bash.
I encountered this problem in MSYS2 proper, even in latest build (x64 2018-05-31).
Luckily, Git for Windows maintain a customized MSYS2 runtime. They have patches that have not been sent upstream, including a patch that fixes emulation of SIGINT, SIGTERM and SIGKILL.
Discussion: https://github.com/nodejs/node/issues/16103
I was able to make my "MSYS2 proper" platform use Git for Windows' MSYS2 runtime, by following these instructions.
Repeated here for posterity:
Install inside MSYS2 proper
This guide assumes that you want the 64-bit version of Git for Windows.
Git for Windows being based on MSYS2, it's possible to install the git package into an existing MSYS2 installation. That means that if you are already using MSYS2 on your computer, you can use Git for Windows without running the full installer or using the portable version.
Note however that there are some caveats for going this way. Git for Windows created some patches for msys2-runtime that have not been sent upstream. (This had been planned, but it was determined in issue #284 that it would probably not be happening.) This means that you have to install Git for Windows customized msys2-runtime to have a fully working git inside MSYS2.
Here the steps to take:
Open an MSYS2 terminal.
Edit /etc/pacman.conf and just before [mingw32] (line #71 on my machine), add the git-for-windows packages repository:
[git-for-windows]
Server = https://wingit.blob.core.windows.net/x86-64
and optionally also the MINGW-only repository for the opposite architecture (i.e. MINGW32 for 64-bit SDK):
[git-for-windows-mingw32]
Server = https://wingit.blob.core.windows.net/i686
Authorize signing key (this step may have to be repeated occasionally until https://github.com/msys2/msys2/issues/62 is fixed)
curl -L https://raw.githubusercontent.com/git-for-windows/build-extra/master/git-for-windows-keyring/git-for-windows.gpg |
pacman-key --add - &&
pacman-key --lsign-key 1A9F3986
Then synchronize new repository
pacboy update
This updates msys2-runtime and therefore will ask you to close the window (not just exit the pacman process). Don't panic, simply close all currently open MSYS2 shells and MSYS2 programs. Once all are closed, start a new terminal again.
Then synchronize again (updating the non-core part of the packages):
pacboy update
And finally install the Git/cURL packages:
pacboy sync git:x git-doc-html:x git-doc-man:x git-extra: curl:x
Finally, check that everything went well by doing git --version in a MINGW64 shell and it should output something like git version 2.14.1.windows.1 (or newer).
Note: I found that the git-extra package installed by step 7 was quite intrusive (it adds a message "Welcome to the Git for Windows SDK!" to every terminal you open), so I removed it with pacman -R git-extra.
Note 2: I also found that Git for Windows' MSYS2 runtime opens in a different home directory than did MSYS2 proper's. This also means it reads in the wrong bash profile. I fixed this by adding an environment variable to Windows in the Control Panel: HOME=/C/msys64/home/myusername
I use git bash on my Windows machine and have run into this issue in the last month or so.
I still do not know what's causing it but I've found another way to stop it.
Open Task Manager
Go into the Processes tab
Look for node.exe and then press End Process
This has allowed me to stop the server quickly.
I had the same problem working with npm. But finally, I knew it was a problem with git itself.
There was a comment by dscho on GitHub 15 days ago. He said that they're working to fix this problem in the next release. He also shared the exact msys-2.0.dll file that can fix the problem for the people who can't wait.
Personally, I couldn't wait :p. So, I gave it a try, downloaded the file, and throw it in the git folder as he said. And the problem gone! It was awesome!
But please be sure to take a backup before you replace the file.
I also tried to kill it after running express as I used to; using taskkill /im node.exe on the cmd but there was no process to be found.
Check out this issue on GitHub,and search for the name of the file msys-2.0.dll to get to the comment faster.
Sometimes the node process hangs.
Check for the process ID using ps You may want to grep for node and then kill the process using kill -9 [PID]
Use Ctrl+\ to send the SIGQUIT signal. It will close the server.
Reference - https://en.wikipedia.org/wiki/Signal_(IPC)
I was able to fix this by switching to nodemon to run the server.
npm install --save-dev nodemon
package.json:
"scripts": {
"start": "nodemon app"
},
I was trying to get json-server to quit a custom server script, but it always left a child process running on Windows. It seems to be a specific problem running express via npm on Windows. If you run the server directly via the c:>node server.js then it seems to quit correctly.
I was able to debug this issue by checking the ports using TCP View, and realizing that my Node server was running even though I had pressed ctrl-C to stop it. I suggest killing the terminal you are running node from entirely.
Use Ctrl + C, then input: >pm2 stop all
This will stop all server or when you get stack with nodejs.
Inside package.json under scripts I had this line react-scripts start&. Notice it ends with an & which would send the process to the background and ctrl+c will not work. Somehow trying to bring this to the foreground with fg also did not work. Solved the problem by removing the &.
if you use Node.js Exec Extention to run your project from f8,
you can use also f9 to cancel running..
This is more than likely just a problem with your console not accurately sending the command to the process. This is pretty common, especially when using third party consoles like cmdr / conemu.
The solution?
Just hit ctrl+c several times until it closes :P
I am running Node.js and Socket.io for online chat.
I have created a file in:
/etc/init/example.conf
it has two lines:
start on startup
exec forever start /var/www/example.com/html/server.js //location of server file.
Whenever I start file upload in chat application, it crashes but instantly restarts.
Whenever I kill node process though, and start it manually - it works fine.
I also can't get any logs or anything from terminal as when it's auto started - it doesn't print me anything to terminal.
I am still new to Node.js and Linux in general.
Node.js is running on Express + Jade.
How do I determine specific cause?
I managed to solve my problem, after a bit of searching around I found out about tail command.
My issue was a bit harder to trace because Node.js was a process started by autostart so when I launched terminal and connected to server, process was just running in background basically and I wouldn't get any output (including exception messages).
Anyway, solution that worked for me was:
I typed
ps aux | grep node //to find PID of node process
then I went to following directory
cd /proc/[pid of running node service]/fd
In fd directory there are few objects you can get output from but if you want to attach and listen to servers output including uncaught exceptions, you need 1.
So:
tail -f 1
that way I was able to cause website to crash and see the output.