How to run application in background in shell script - linux

I have a dotnet application and I want to publish it in the container. I have one requirement, when the application is started I have to push some data in my application.
To do that I created a shell script and put it in the entry point command. Now I am running my application using a shell script.
The problem is when the application is started the script is not running the commands below it.
This is my shell script:
cd /app/WebAPI
dotnet WebAPI.dll
cd /app/data
for f in `ls *.txt`; do
// some other command
done
I want to run this for loop after the application is started.

Summarizing the comments above:
cd /app/WebAPI
dotnet WebAPI.dll &
cd /app/data
for f in *.txt; do
# some other command
done

Related

How to run another serve after node server has started using shell script?

I want to write a script which basically runs my node server first and after only node server has started I want to run another script. How can I implement this using shell script?
Right now I have done this so far
echo "Going inside NodeServer folder";
cd ./../Server-Node
echo "Starting Node Server";
npm start
echo 'Going inside Project Folder';
cd ./../ionicApp
ionic serve
A simple hack is to use npm start & add a sleep 15 on the line after it (or adjust accordingly to the avg time the start takes).
Note: to terminate the node process you might have to run a command to kill it stop all instances of node.js server
Otherwise you'll want to look at some stuff here NPM run parallel task, but wait until resource is available to run second task
I found out this later. adding modified script
echo "Going inside Server-Node";
cd ./../Server-Node
echo "Starting Node Server";
npm start & echo OK
echo 'Going inside ionic-Project';
cd ./../learn-ionic
echo 'Starting ionic server';
ionic serve

Jenkins : bash script ran with nohup is neither working nor writing anything to log

BACKGROUND
I would like to explain the scenario properly here.
I am running jenkins_2.73.3 in my cloud server with ubuntu 16.04.
Currently, there are 3 users in the server:
root
develop-user (which I had created for many reasons such as test,deploy etc)
jenkins (which was created by jenkins ofcourse, I also added this jenkins user to sudoers group)
PROBLEM
I have a bash script that I am calling from a build step in Jenkins. Within this bash script,there is a nohup command for calling a separate deployScript in the background such as:
#!/bin/bash
nohup deployScript.sh > $WORKSPACE/app.log 2>&1 & echo $! > save_pid.txt
After the build step is completed, I see that a id is generated inside save_pid.txt but app.log is surprisingly empty. I can't kill any processes with this generated pid. So, that means there isn't any process created in the first place here. Also, the deployScript.sh does not seem to have any effect at all. It's just not working. This happens everytime I run the build in Jenkins. I can assure that there is nothing wrong with the deployScript.sh.
I have tried running this bash script with the develop-user manually without Jenkins and it works perfectly. Contents are written to the log file and also I can use the generated pid to kill the process. I have also tested this in my local environment and it works.
QUESTION
I have been looking at this for days. What might be the root cause here ?Where can I look into to see some logs or other info ? How is the pid generated whereas the log file is empty ? Is it a permission issue with the jenkins user ? Please help.
You can use below line inside the execute shell in jenkins to run it in background without the process being killed.
BUILD_ID=dontKillMe <command> &
So, it turned out to be a permission issue and also the script wasn't executable I guess as pointed out in the comments above.
So, now the bash script looks like below:
#!/bin/bash
sudo chmod a+x deployScript.sh
sudo nohup deployScript.sh > $WORKSPACE/app.log 2>&1 & echo $! > save_pid.txt
This works.

how to start the tomcat server in linux?

i tried to install
1.yum install -zxvf apache-tomcat-6.0.47.tar.gz then
2. export TOMCAT_HOME=/home/mpatil/softwares/apache-tomcat-6.0.37
3. [root#localhost mpatil]# echo $TOMCAT_HOME
/home/mpatil/softwares/apache-tomcat-7.0.47
while starting tomcat by using this command
4.[root#localhost mpatil]# /startup.sh
bash: /startup.sh: No such file or directory
i don't know why it showing like this.
my file in
5.[root#localhost mpatil]# find /home -type f -name apache-tomcat-6.0.37.tar.gz
/home/mpatil/Downloads/apache-tomcat-6.0.37.tar.gz
what i tried before this is is correct or not? --please tell me
my question is how to start a tomcat server in linux.Please tell me..
The command you have typed is /startup.sh, if you have to start a shell script you have to fire the command as shown below:
$ cd /home/mpatil/softwares/apache-tomcat-7.0.47/bin
$ sh startup.sh
or
$ ./startup.sh
Please try that, you also have to go to your tomcat's bin-folder (by using the cd-command) to execute this shell script. In your case this is /home/mpatil/softwares/apache-tomcat-7.0.47/bin.
Use ./catalina.sh start to start Tomcat. Do ./catalina.sh to get the usage.
I am using apache-tomcat-6.0.36.
if you are a sudo user i mean if you got sudo access:
sudo sh startup.sh
otherwise:
sh startup.sh
But things is that you have to be on the bin directory of your server like
cd /home/nanofaroque/servers/apache-tomcat-7.0.47/bin
I know this is old question, but this command helped me!
Go to your Tomcat Directory
Just type this command in your terminal:
./catalina.sh start
cd apache-tomcat-6.0.43 ====: Go to Tomcat Directory
sh bin/startup.sh =====: Start the tomcat on Linux
sh bin/shutdown.sh ======:Shut Down the tomcat on Linux
tail -f logs/catelina.out ====: Check the logs
Go to your Tomcat Directory with : cd/home/user/apache-tomcat6.0
sh bin/startup.sh.>> tail -f logs/catelina.out.>>
Go to the appropriate subdirectory of the EDQP Tomcat installation directory. The default directories are:
On Linux: /opt/server/tomcat/bin
On Windows: c:\server\tomcat\bin
Run the startup command:
On Linux: ./startup.sh
On Windows: % startup.bat
Run the shutdown command:
On Linux: ./shutdown.sh
On Windows: % shutdown.bat
To run Apache Tomcat server in Linux following ways can be used. Let me share the difference as well since I see some got confusions with the multiple ways Apache Tomcat Server can be started.
The catalina.sh is the main control script for Tomcat. Following are the multiple ways of running tomcat:
./catalina.sh run
Passing "run" argument for catalina.sh --> starts the Tomcat in the foreground and displays the running logs in the same console. when the console terminal is closed it will terminate the tomcat.
./catalina.sh start
Passing "start" argument for catalina.sh --> starts the Tomcat in the background. Since in background no issues closing down the terminal. The logs need to be viewed as below: tail -f $CATALINA_HOME/logs/catalina.out
./startup.sh
The last way is firing the startup.sh to start your Tomcat server. If you Vi the script you can see it calls catalina.sh script passing start as the argument. This will be running in background as well.

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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