Automatically starting Celery from within Django app - linux

I am getting a Django 1.6 set up started on a Linux (Debian Whiskey) server on Google Compute Engine. I've got Celery 3.1 running in the background to help with some processes. When I start a new instance (using a snapshot I've created), I always need to start Celery. I am looking for a way to start Celery automatically on server-load. This is particularly helpful if the server decides to restart, as they seem to do now and then. To achieve this, I've edited the rc.local file:
$ sudo nano /etc/rc.local
It used to contain the following:
exit 0
[ -x /sbin/initctl ] && initctl emit --no-wait google-rc-local-has-run || true
I've edited the file such that it now reads:
cd /home/user/gce_app celery -A myapp.tasks --concurrency=1 --loglevel=info worker > output.log 2> errors.log &
exit 0
[ -x /sbin/initctl ] && initctl emit --no-wait google-rc-local-has-run || true
The directory:
/home/user/gce_app
is where my Django project resides and the directory I need to be in to start Celery. However, after restarting the instance, when I type in:
$ celery status
Error: No nodes replied within time constraint.
Opening the errors.log file, I see:
/etc/rc.local: 14: /etc/rc.local: celery: not found
Surely the cd at the start of that code string should address this? Is there a way (within the Django project itself) to start the Celery instance when the project is started to make the code more platform-independent and immune to inevitable OS updates?

I think you're missing a semicolon between your 'cd' and celery invocations. Also, I suspect rc.local may not be searching your path, so you may need to give an absolute path to celery. e.g.
cd /home/user/gce_app; /usr/bin/celery ...
Alternatively, you might look at using a startup script from the GCE metadata to avoid needing to modify rc.local.

Since you seem to be using upstart this might help you:
description "runs celery"
start on runlevel [2345]
stop on runlevel [!2345]
console log
env VENV='/srv/myvirtualenv'
env PROJECT='/srv/run/mydjangoproject'
exec su -s /bin/sh -c 'exec "$0" "$#"' www-data -- /usr/bin/env PATH=$VENV:$PATH $VENV/python $PROJECT/manage.py celeryd
respawn
respawn limit 10 5

Related

Ubuntu upstart gets incorrect PID from Play 1.3

The Upstart script using the start-stop-daemon we've been using for Play 1.2.7 is now unable to stop/restart Play since Play 1.3 due to it having an incorrect PID.
Framework version: 1.3.0 on Ubuntu 12.04.5 LTS
Reproduction steps:
Setup an upstart script (playframework.conf) for a Play application
Play application starts successfully on server reboot Run 'sudo
status playframework' will return playframework start/running,
process 28912 - At this point process 28912 doesn't exist
vi {playapplicationfolder}/server.pid shows 28927
'stop playframework'
then fails due to unknown pid 28912 'status playframework' results in
playframework stop/killed, process 28912
Only way to restart play framework after this point is to either find the actual process and kill it then start play using the usual 'play start' command manually. Or restart the server.
This has broken our deployments scripts now as we used to install the new version of our app, then do play restart before reconnecting to the load balancer.
Upstart Script:
#Upstart script for a play application that binds to an unprivileged user.
# put this into a file like /etc/init/playframework
# you can then start/stop it using either initctl or start/stop/restart
# e.g.
# start playframework
description "PlayApp"
author "-----"
version "1.0"
env PLAY_BINARY=/opt/play/play
env JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
env HOME=/opt/myapp/latest
env USER=ubuntu
env GROUP=admin
env PROFILE=prod
start on (filesystem and net-device-up IFACE=lo) or runlevel [2345]
stop on runlevel [!2345]
limit nofile 65536 65536
respawn
respawn limit 10 5
umask 022
expect fork
pre-start script
test -x $PLAY_BINARY || { stop; exit 0; }
test -c /dev/null || { stop; exit 0; }
chdir ${HOME}
rm ${HOME}/server.pid || true
/opt/configurer.sh
end script
pre-stop script
exec $PLAY_BINARY stop $HOME
end script
post-stop script
rm ${HOME}/server.pid || true
end script
script
exec start-stop-daemon --start --exec $PLAY_BINARY --chuid $USER:$GROUP --chdir $HOME -- start $HOME -javaagent:/opt/newrelic/newrelic.jar --%$PROFILE -Dprecompiled=true --http.port=8080 --https.port=4443
end script
We've tried specifying the PID file in the start-stop-daemon as per: http://man.he.net/man8/start-stop-daemon however this also didnt seem to have any effect.
I have found some threads on similar issues https://askubuntu.com/questions/319199/upstart-tracking-wrong-pid-of-process-not-respawning but have been unable to find a way round this so far. I have tried changing fork to daemon but the same issue remains. I also can't see what has changed between Play 1.2.7 and 1.3 to cause this.
Another SO post has also asked a similar question but not had an answer as yet: https://stackoverflow.com/questions/23117345/upstart-gets-wrong-pid-after-launching-celery-with-start-stop-daemon
This is because getJavaVersion() spawns a subprocess, which bumps the PID count, which breaks Upstart, the latter which expects Play to fork exactly none, once or twice, depending on which expect stanza you use.
I've fixed this in a pull request.

UPSTART script non root not working

I'm trying to run a nodejs application using upstart as a non root user.
But somehow parts of the script will not run : for instance:
if I run it like a root user(below example) NODE_ENV never gets called/set
the only way to called is with "sudo initctl stop pdcapp"
sudo nameofApp start|stop would not work
When called sudo initctl stop nameofApp the pre-stop script will not echo to the log file
if I try to runit like a non root user it would not even start
isn't a more cleaner easier way of doing this (systemd) I've looked a various tutorials around and apparently this is how they've doneit. so what am I missing here?
This is the .conf file under /etc/init/
env FULL_PATH="/srv/pd/sept011100/dev"
env NODE_PATH="/usr/local/nodeJS/bin/node"
env NODE_ENV=production
start on filesystem or runlevel [2345]
stop on [!2345]
script
export NODE_ENV #this variable is never set
echo $$ > /var/run/PD.pid
cd $FULL_PATH
# the command below will not work
#exec sudo -u nginx "$NODE_PATH server.js >> /var/log/PD/pdapp.log 2>&1"
exec $NODE_PATH server.js >> /var/log/PD/pdapp.log 2>&1
end script
pre-start script
echo "[`date`] (sys) Starting" >> /var/log/PD/pdapp.log
end script
pre-stop script
rm /var/run/pdapp.pid
echo "[`date`] (sys) Stopping" >> /var/log/PDC/pdapp.log
end script
in /var/log/messages I get this when I stop the application, otherwise I get nothing in the logfile
Sep 2 18:23:14 547610-redhat-dev2 init: pdcapp pre-stop process (6903) terminated with status 1
Sep 2 18:23:14 547610-redhat-dev2 init: pdcapp main process (6899) terminated with status 143
any Ideas why is this not working I'm running redhat 6.5
Red Hat has a super old version of Upstart that is probably full of bugs because they never contributed to Upstart, despite using it (Fedora switched to systemd right after RHEL 6 was released, before they even really tried it out well).

Script not starting on boot with start-stop-daemon

My script (located in /etc/init.d) is creating a pid file ($PIDFILE), but there is no process running. My daemon script includes:
start-stop-daemon --start --quiet --pidfile $PIDFILE -m -b --startas $DAEMON --test > /dev/null || return 1
The script works fine when executing it manually.
You need to create startup links.
sudo update-rc.d SCRIPT_NAME defaults
then reboot. SCRIPT_NAME is the name of the script in /etc/init.d (Without the path)
Was able to get it working, but tried so many things, don't know exactly what fixed it (probably an error in script or config). However, learned a lot and wanted to share since I can't find much of the same in the internet abyss.
It seems Ubuntu (and many other distros based on Ubuntu, including Mint) has migrated to Upstart for job and service management. Upstart includes SysVinit (using /etc/init.d daemons) compatibility that still can use update-rc.d to manage daemons (so if you are familiar with that usage, you can keep on using it). The Upstart method is to use a single .conf file in the /etc/init folder. My SCRIPT.conf file is very simple (I'm using a python script):
start on filesystem or runlevel [2345]
stop on runlevel [016]
exec python /usr/share/python-support/SCRIPT/SCRIPT.py
This simple file completely replaces the standard script in /etc/init.d with the case statement to provide [start|stop|restart|reload] functions and the pointer to /usr/bin/SCRIPT. You can see that it includes runlevel control that would normally be found in the /etc/rc*.d files (thus eliminating several files).
I tried update-rc.d to create the necessary /etc/rc*.d/ files for my daemon. My daemon bash script is located in /etc/init.d and includes the start-stop-daemon command as in my original question. (That command also works fine from terminal.)
I had /etc/rc*.d/ files, the bash script in /etc/init.d and /etc/init/SCRIPT.conf file during boot and it seems that Upstart likely first looks for the .conf file for its direction because the SysVinit command service SCRIPT [start|stop|restart|reload] returns Unknown Instance, however you can find the process is running with ps -elf | grep SCRIPT_FILE.
One interesting thing to note is the forking of your daemon when using .conf. The script as written above only spawns one fork of the daemon. However, total independence of the original script is possible by using expect fork or expect daemon and respawn (see the Upstart Cookbook for reference). Using these will ensure that your daemon will never be killed (at least by using the kill command).
I continued to test both my daemon and the boot process by utilizing the sudo initctl reload-configuration command. This reloads the conf files where you can test your daemon by the sudo [start|stop|restart] SCRIPT command. The result of the start command is:
$ sudo start SCRIPT
SCRIPT start/running, process xxxx
$ sudo restart SCRIPT
SCRIPT start/running, process xxxx
$ sudo stop SCRIPT
SCRIPT stop/waiting
Also, there is a nice log in /var/log/upstart/SCRIPT.log that gives you useful information for your daemon during boot. Mine still has a very annoying bug that prevents root from displaying osd messages with notify-send from my daemon. My log file includes a gtk warning (I will open another question to solicit help).
Hope this helps others in developing their daemons.

Automatically start forever (node) on system restart

I am using node's forever module to keep my node server running. Forever however terminates when there is a system restart. Is there any way I can automatically start the node server (with forever) when the system restarts?
I would suggest using crontab. It's easy to use.
How to
To start editing run the following replacing the "testuser" with your desired runtime user for the node process. If you choose a different user other than yourself, you will have to run this with sudo.
$ crontab -u testuser -e
If you have never done this before, it will ask you which editor you wish to edit with. I like vim, but will recommend nano for ease of use.
Once in the editor add the following line:
#reboot /usr/local/bin/forever start /your/path/to/your/app.js
Save the file. You should get some feedback that the cron has been installed.
For further confirmation of the installation of the cron, execute the following (again replacing "testuser" with your target username) to list the currently installed crons:
$ crontab -u testuser -l
Note that in my opinion, you should always use full paths when executing binaries in cron.
Also, if the path to your forever script is not correct, run which forever to get the full path.
Given that forever calls node, you may also want to provide the full path to node:
#reboot /usr/local/bin/forever start -c /usr/local/bin/node /your/path/to/your/app.js
Further Reading
crontab Man Page
Ubuntu Cron HowTo
You can use forever-service for doing this.
npm install -g forever-service
forever-service install test
This will provision app.js in the current directory as a service via forever. The service will automatically restart every time system is restarted. Also when stopped it will attempt a graceful stop. This script provisions the logrotate script as well.
Github url: https://github.com/zapty/forever-service
NOTE: I am the author of forever-service.
Install PM2 globally using NPM
npm install pm2 -g
Start your script with pm2
pm2 start app.js
generate an active startup script
pm2 startup
NOTE: pm2 startup is for startting the PM2 when the system reboots. PM2 once started, restarts all the processes it had been managing before the system went down.
In case you want to disable the automatic startup, simply use pm2 unstartup
If you want the startup script to be executed under another user, just use the -u <username> option and the --hp <user_home>:
This case is valid for Debian.
Add the following to /etc/rc.local
/usr/bin/sudo -u {{user}} /usr/local/bin/forever start {{app path}}
{{user}} replaces your username.
{{app path}} replaces your app path. For example, /var/www/test/app.js
An alternative crontab method inspired by this answer and this blog post.
1. Create a bash script file (change bob to desired user).
vi /home/bob/node_server_init.sh
2. Copy and paste this inside the file you've just created.
#!/bin/sh
export NODE_ENV=production
export PATH=/usr/local/bin:$PATH
forever start /node/server/path/server.js > /dev/null
Make sure to edit the paths above according to your config!
3. Make sure the bash script can be executed.
chmod 700 /home/bob/node_server_init.sh
4. Test the bash script.
sh /home/bob/node_server_init.sh
5. Replace "bob" with the runtime user for node.
crontab -u bob -e
6. Copy and paste (change bob to desired user).
#reboot /bin/sh /home/bob/node_server_init.sh
Save the crontab.
You've made it to the end, your prize is a reboot (to test) :)
Copied answer from the attached question.
You can use PM2, it's a production process manager for Node.js applications with a built-in load balancer.
Install PM2
$ npm install pm2 -g
Start an application
$ pm2 start app.js
If you using express then you can start your app like
pm2 start ./bin/www --name="app"
Listing all running processes:
$ pm2 list
It will list all process. You can then stop / restart your service by using ID or Name of the app with following command.
$ pm2 stop all
$ pm2 stop 0
$ pm2 restart all
To display logs
$ pm2 logs ['all'|app_name|app_id]
You need to create a shell script in the /etc/init.d folder for that. It's sort of complicated if you never have done it but there is plenty of information on the web on init.d scripts.
Here is a sample a script that I created to run a CoffeeScript site with forever:
#!/bin/bash
#
# initd-example Node init.d
#
# chkconfig: 345
# description: Script to start a coffee script application through forever
# processname: forever/coffeescript/node
# pidfile: /var/run/forever-initd-hectorcorrea.pid
# logfile: /var/run/forever-initd-hectorcorrea.log
#
# Based on a script posted by https://gist.github.com/jinze at https://gist.github.com/3748766
#
# Source function library.
. /lib/lsb/init-functions
pidFile=/var/run/forever-initd-hectorcorrea.pid
logFile=/var/run/forever-initd-hectorcorrea.log
sourceDir=/home/hectorlinux/website
coffeeFile=app.coffee
scriptId=$sourceDir/$coffeeFile
start() {
echo "Starting $scriptId"
# This is found in the library referenced at the top of the script
start_daemon
# Start our CoffeeScript app through forever
# Notice that we change the PATH because on reboot
# the PATH does not include the path to node.
# Launching forever or coffee with a full path
# does not work unless we set the PATH.
cd $sourceDir
PATH=/usr/local/bin:$PATH
NODE_ENV=production PORT=80 forever start --pidFile $pidFile -l $logFile -a -d --sourceDir $sourceDir/ -c coffee $coffeeFile
RETVAL=$?
}
restart() {
echo -n "Restarting $scriptId"
/usr/local/bin/forever restart $scriptId
RETVAL=$?
}
stop() {
echo -n "Shutting down $scriptId"
/usr/local/bin/forever stop $scriptId
RETVAL=$?
}
status() {
echo -n "Status $scriptId"
/usr/local/bin/forever list
RETVAL=$?
}
case "$1" in
start)
start
;;
stop)
stop
;;
status)
status
;;
restart)
restart
;;
*)
echo "Usage: {start|stop|status|restart}"
exit 1
;;
esac
exit $RETVAL
I had to make sure the folder and PATHs were explicitly set or available to the root user since init.d scripts are ran as root.
Use the PM2
Which is the best option to run the server production server
What are the advantages of running your application this way?
PM2 will automatically restart your application if it crashes.
PM2 will keep a log of your unhandled exceptions - in this case, in a file at /home/safeuser/.pm2/logs/app-err.log.
With one command, PM2 can ensure that any applications it manages restart when the server reboots. Basically, your node application will start as a service.
ref: https://www.digitalocean.com/community/tutorials/how-to-use-pm2-to-setup-a-node-js-production-environment-on-an-ubuntu-vps
Forever was not made to get node applications running as services. The right approach is to either create an /etc/inittab entry (old linux systems) or an upstart (newer linux systems).
Here's some documentation on how to set this up as an upstart:
https://github.com/cvee/node-upstart
crontab does not work for me on CentOS x86 6.5. #reboot seems to be not working.
Finally I got this solution:
Edit: /etc/rc.local
sudo vi /etc/rc.local
Add this line to the end of the file. Change USER_NAME and PATH_TO_PROJECT to your own. NODE_ENV=production means the app runs in production mode. You can add more lines if you need to run more than one node.js app.
su - USER_NAME -c "NODE_ENV=production /usr/local/bin/forever start /PATH_TO_PROJECT/app.js"
Don't set NODE_ENV in a separate line, your app will still run in development mode, because forever does not get NODE_ENV.
# WRONG!
su - USER_NAME -c "export NODE_ENV=production"
Save and quit vi (press ESC : w q return). You can try rebooting your server. After your server reboots, your node.js app should run automatically, even if you don't log into any account remotely via ssh.
You'd better set NODE_ENV environment in your shell. NODE_ENV will be set automatically when your account USER_NAME logs in.
echo export NODE_ENV=production >> ~/.bash_profile
So you can run commands like forever stop/start /PATH_TO_PROJECT/app.js via ssh without setting NODE_ENV again.
I wrote a script that does exactly this:
https://github.com/chovy/node-startup
I have not tried with forever, but you can customize the command it runs, so it should be straight forward:
/etc/init.d/node-app start
/etc/init.d/node-app restart
/etc/init.d/node-app stop
The problem with rc.local is that the commands are accessed as root which is different than logging to as a user and using sudo.
I solved this problem by adding a .sh script with the startup commands i want to etc/profile.d. Any .sh file in profile.d will load automatically and any command will be treated as if you used the regular sudo.
The only downside to this is the specified user needs to loggin for things to start which in my situation was always the case.
I tried lots of the above answers. None of them worked for me. My app is installed in /home and as user, not as root. This probably means that when the above mentioned start scripts run, /home is not mounted yet, so the app is not started.
Then I found these instructions by Digital Ocean:
https://www.digitalocean.com/community/tutorials/how-to-use-pm2-to-setup-a-node-js-production-environment-on-an-ubuntu-vps
Using PM2 as explained was very simple and works perfectly: My virtual servers had two physical crashes since - downtime was only about a minute.
complete example crontab (located at /etc/crontab) ..
#!/bin/bash
# edit this file with .. crontab -u root -e
# view this file with .. crontab -u root -l
# put your path here if it differs
PATH=/root/bin:/root/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin
# * * * * * echo "executes once every minute" > /root/deleteme
#reboot cd /root/bible-api-dbt-server; npm run forever;
#reboot cd /root/database-api-server; npm run forever;
#reboot cd /root/mailer-api-server; npm run forever;
I have found my own solution by using serve & npm as follows:
Install serve package: npm install -g serve
Then have the command serve -s /var/www/sitename to execute on reboot.
This is what works for me on my VPS.
You can use the following command in your shell to start your node forever:
forever app.js //my node script
You need to keep in mind that the server on which your app is running should always be kept on.

How to run Node.js as a background process and never die?

I connect to the linux server via putty SSH. I tried to run it as a background process like this:
$ node server.js &
However, after 2.5 hrs the terminal becomes inactive and the process dies. Is there anyway I can keep the process alive even with the terminal disconnected?
Edit 1
Actually, I tried nohup, but as soon as I close the Putty SSH terminal or unplug my internet, the server process stops right away.
Is there anything I have to do in Putty?
Edit 2 (on Feb, 2012)
There is a node.js module, forever. It will run node.js server as daemon service.
nohup node server.js > /dev/null 2>&1 &
nohup means: Do not terminate this process even when the stty is cut
off.
> /dev/null means: stdout goes to /dev/null (which is a dummy
device that does not record any output).
2>&1 means: stderr also goes to the stdout (which is already redirected to /dev/null). You may replace &1 with a file path to keep a log of errors, e.g.: 2>/tmp/myLog
& at the end means: run this command as a background task.
Simple solution (if you are not interested in coming back to the process, just want it to keep running):
nohup node server.js &
There's also the jobs command to see an indexed list of those backgrounded processes. And you can kill a backgrounded process by running kill %1 or kill %2 with the number being the index of the process.
Powerful solution (allows you to reconnect to the process if it is interactive):
screen
You can then detach by pressing Ctrl+a+d and then attach back by running screen -r
Also consider the newer alternative to screen, tmux.
You really should try to use screen. It is a bit more complicated than just doing nohup long_running &, but understanding screen once you never come back again.
Start your screen session at first:
user#host:~$ screen
Run anything you want:
wget http://mirror.yandex.ru/centos/4.6/isos/i386/CentOS-4.6-i386-binDVD.iso
Press ctrl+A and then d. Done. Your session keeps going on in background.
You can list all sessions by screen -ls, and attach to some by screen -r 20673.pts-0.srv command, where 0673.pts-0.srv is an entry list.
This is an old question, but is high ranked on Google. I almost can't believe on the highest voted answers, because running a node.js process inside a screen session, with the & or even with the nohup flag -- all of them -- are just workarounds.
Specially the screen/tmux solution, which should really be considered an amateur solution. Screen and Tmux are not meant to keep processes running, but for multiplexing terminal sessions. It's fine, when you are running a script on your server and want to disconnect. But for a node.js server your don't want your process to be attached to a terminal session. This is too fragile. To keep things running you need to daemonize the process!
There are plenty of good tools to do that.
PM2: http://pm2.keymetrics.io/
# basic usage
$ npm install pm2 -g
$ pm2 start server.js
# you can even define how many processes you want in cluster mode:
$ pm2 start server.js -i 4
# you can start various processes, with complex startup settings
# using an ecosystem.json file (with env variables, custom args, etc):
$ pm2 start ecosystem.json
One big advantage I see in favor of PM2 is that it can generate the system startup script to make the process persist between restarts:
$ pm2 startup [platform]
Where platform can be ubuntu|centos|redhat|gentoo|systemd|darwin|amazon.
forever.js: https://github.com/foreverjs/forever
# basic usage
$ npm install forever -g
$ forever start app.js
# you can run from a json configuration as well, for
# more complex environments or multi-apps
$ forever start development.json
Init scripts:
I'm not go into detail about how to write a init script, because I'm not an expert in this subject and it'd be too long for this answer, but basically they are simple shell scripts, triggered by OS events. You can read more about this here
Docker:
Just run your server in a Docker container with -d option and, voilá, you have a daemonized node.js server!
Here is a sample Dockerfile (from node.js official guide):
FROM node:argon
# Create app directory
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
# Install app dependencies
COPY package.json /usr/src/app/
RUN npm install
# Bundle app source
COPY . /usr/src/app
EXPOSE 8080
CMD [ "npm", "start" ]
Then build your image and run your container:
$ docker build -t <your username>/node-web-app .
$ docker run -p 49160:8080 -d <your username>/node-web-app
Always use the proper tool for the job. It'll save you a lot of headaches and over hours!
another solution disown the job
$ nohup node server.js &
[1] 1711
$ disown -h %1
nohup will allow the program to continue even after the terminal dies. I have actually had situations where nohup prevents the SSH session from terminating correctly, so you should redirect input as well:
$ nohup node server.js </dev/null &
Depending on how nohup is configured, you may also need to redirect standard output and standard error to files.
Nohup and screen offer great light solutions to running Node.js in the background. Node.js process manager (PM2) is a handy tool for deployment. Install it with npm globally on your system:
npm install pm2 -g
to run a Node.js app as a daemon:
pm2 start app.js
You can optionally link it to Keymetrics.io a monitoring SAAS made by Unitech.
$ disown node server.js &
It will remove command from active task list and send the command to background
I have this function in my shell rc file, based on #Yoichi's answer:
nohup-template () {
[[ "$1" = "" ]] && echo "Example usage:\nnohup-template urxvtd" && return 0
nohup "$1" > /dev/null 2>&1 &
}
You can use it this way:
nohup-template "command you would execute here"
Have you read about the nohup command?
To run command as a system service on debian with sysv init:
Copy skeleton script and adapt it for your needs, probably all you have to do is to set some variables. Your script will inherit fine defaults from /lib/init/init-d-script, if something does not fits your needs - override it in your script. If something goes wrong you can see details in source /lib/init/init-d-script. Mandatory vars are DAEMON and NAME. Script will use start-stop-daemon to run your command, in START_ARGS you can define additional parameters of start-stop-daemon to use.
cp /etc/init.d/skeleton /etc/init.d/myservice
chmod +x /etc/init.d/myservice
nano /etc/init.d/myservice
/etc/init.d/myservice start
/etc/init.d/myservice stop
That is how I run some python stuff for my wikimedia wiki:
...
DESC="mediawiki articles converter"
DAEMON='/home/mss/pp/bin/nslave'
DAEMON_ARGS='--cachedir /home/mss/cache/'
NAME='nslave'
PIDFILE='/var/run/nslave.pid'
START_ARGS='--background --make-pidfile --remove-pidfile --chuid mss --chdir /home/mss/pp/bin'
export PATH="/home/mss/pp/bin:$PATH"
do_stop_cmd() {
start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 \
$STOP_ARGS \
${PIDFILE:+--pidfile ${PIDFILE}} --name $NAME
RETVAL="$?"
[ "$RETVAL" = 2 ] && return 2
rm -f $PIDFILE
return $RETVAL
}
Besides setting vars I had to override do_stop_cmd because of python substitutes the executable, so service did not stop properly.
Apart from cool solutions above I'd mention also about supervisord and monit tools which allow to start process, monitor its presence and start it if it died. With 'monit' you can also run some active checks like check if process responds for http request
For Ubuntu i use this:
(exec PROG_SH &> /dev/null &)
regards
Try this for a simple solution
cmd & exit

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