How to Start a Server Via SSH and Leave it Running?

Development Software Development
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1

I have a node.js server and redis I need to start via ssh for a simple web app to start on a remote server I setup. I tried using tmux to connect to the server and start the two processes and then I detach the process. At this point I can still connect to the website. I then restart my local machine I was ssh'ing into my server and then I can no longer connect to my web app. Would anybody know how I can start the process on Ubunut server and disconnect and for the process not to stop?

2

Something like nohup command & should work. Where command is whatever command you use to start the service.

2 Likes
3

i use to have a little shell script in rc.local on ubuntu server that would execute screen commands to get things like MC servers up and running but also leave them detached so i could just come back later if needed. there are probably better ways of doing it but thats how i used to do it. for node.js too you can use something like PM2 and have it help you with handing what node.js apps need to be running on startup.

4

You can either:
- Daemonize node.js using Forever
- Use disown 

$ ./app > app.log 2>app.err &
[1] 1234
$ disown %%
  1. Use nohup ./app - but you won't be able to shut it down gracefully with kill.
5

my solution on my server is just to use screen though i have a separete user account for every server.

just run screen and then run whatever program you want to run. If you lose the ssh connection then just run "screen -d -r" will drop you right where you left off

EX:

ssh [email protected]
$ screen
$ sever-ssh.sh
SSH connection to host.com dropped
ssh [email protected]
$ screen -d -r

1 Like
6

you could write a .service file and use systemd to control it. you will need the program to change user to a nonprivileged account once started.

[Unit]
Description=your description here
After=network.target
[Service]
ExecStart=full path to your command here
[Install]
WantedBy=multi-user.target

next 

 systemctl enable your_name.service

this will run it on startup
then 

 systemctl start your_name


other options : stop restart

info taken from here
more info on systemd

run as another user:
change 

ExecStart=full path to your command here


to 

ExecStart=/bin/su user -c full path to your command here

note : /bin/su might be a different path on ubuntu than specified above

2 Likes
7

for node js stuff i like pm2

sudo npm install -g pm2
then
pm2 start "your app"

then just use
pm2 startup systemd
if you have any trouble here's a guide


scroll down to the pm2 part near the bottom

8

I have used this, and you can name screen sessions for easier re-attachment of different sessions later.

1 Like
9

Thanks your solution worked the best!!!

10

I'm not sure what your asking but you can create a permanent ssh tunnel between a web app and a remote database. You can use the following after setting up keys. With some debugging/modifying. 

  CreateTunnel() {
    /usr/bin/ssh -f -N -L13306:hostb:3306 -L19922:hostb:22 tunnel@hostb
    if [[ $? -eq 0 ]]; then
        echo Tunnel to hostb created successfully
    else
        echo An error occurred creating a tunnel to hostb RC was $?
    fi
}
## Run the 'ls' command remotely.  If it returns non-zero, then create a new connection
/usr/bin/ssh -p 19922 tunnel@localhost ls
if [[ $? -ne 0 ]]; then
    echo Creating new tunnel connection
    createTunnel
fi

Yes, I stole that from the internet, and no you don't need most of that crap, just check out the ssh command.

Hopefully that provides an option for you.

11

nano /etc/init.d/<> && ln -s /etc/init.d/<> /etc/rc5.d
put some script here, just make sure it includes the start/stop/etc cases, you can google examples of these easily.
This would start which ever scripting you put inside the start tag when ever the OS hits runlevel 5.
it may take a try or two but once you get the hang of it, it really makes sense.
also you can create your own status, restart, etc. cases.