B4J Question Linux web-app autostart

[peacemaker]

Hi, All

How to make sure that app is autostarted undex Linux ?

Tried to use crontab - does not start after reboot.

crontab -e
@reboot nohup /var/www/project/data/www/project/jdk-14.0.1/bin/java -jar /var/www/project/data/www/project/result.jar > nohup.out &

App is started with nohup by this above command only if to start manually from the app folder.
Ubuntu 22.04 server VPS (not desktop), if important.
SUDO before command does not help also.

Any suggestions ?

 

[aeric]

I created a script in home directory and call in crontab

#!/bin/bash
cd /home/aeric
nohup /usr/bin/java -jar myapp.jar > nohup.out &

$ sudo crontab -e

@reboot sudo /home/aeric/startup.sh

 

[peacemaker]

Thanks, Aeric, but if to start...

startup.sh: command not found

Rights are 755.

Script is re-typed anew on LInux:

manually started, but not from startup.sh

 

[aeric]

I store the file inside home

 

[Jones Hone]

The following is my practice, for your reference.
Not sure it's also suitable for your environment.
*.Please pay attention to whether the firewall has opened the port you want to use.
0. my environment:
Oracle Cloud Free Tier VPS: Ubuntu 20.04.3 LTS
My web-app in /home/ubuntu/b4jwebhook/WebHook.jar
1.create mywebhook.service file:
sudo vim /etc/systemd/system/mywebhook.service <Enter>
2. The content of mywebhook.service is as follows:
[Unit]
Description=This is my webhook
After=network.target
[Service]
# User=user
# Group=group
WorkingDirectory=/home/ubuntu/b4jwebhook
ExecStart=sh /home/ubuntu/b4jwebhook/webhookrun.sh
Restart=always
RestartSec=3s
RemainAfterExit=yes
[Install]
WantedBy=multi-user.target
3.After the file is created, execute the following command:
sudo chmod 755 /etc/systemd/system/mywebhook.service <Enter>
sudo systemctl daemon-reload<Enter>
sudo systemctl enable mywebhook.service<Enter>
4.create webhookrun.sh file:
sudo vim /home/ubuntu/b4jwebhook/webhookrun.sh <Enter>
5. The content of webhookrun.sh is as follows:
nohup sudo java -jar WebHook.jar &
6.After the file is created, execute the following command:
sudo chmod 755 /home/ubuntu/b4jwebhook/webhookrun.sh <Enter>

7.Ok. Now reboot the VPS, The web server is autostart.

 

[aeric]

Ya, sometimes we need to take care of file permission issue if something not work.

 

[aeric]

I remember I read somewhere that /home directory is mounted earlier when system booted than other directory so it is a better place to store the sh file.

 

[peacemaker]

I store the file inside home

Thanks. What is rights of this home/user folder ?
I re-installed the server, installed FTP, created a user, connected by FTP, but files are not saved into /home/user...

 

[aeric]

Thanks. What is rights of this home/user folder ?
I re-installed the server, installed FTP, created a user, connected by FTP, but files are not saved into /home/user...

Not sure but if you are logged in as root then should be no issue with access rights.

 

[aminoacid]

Use systemd as specified in Post#5. I use this all the time to autostart my JAR files reliably.

 

[teddybear]

I don't know which linux you use.
Try add startup script in /etc/rc.local file, or do it by Post#5

 

[OliverA]

Technically, you don't need a separate script to run your non-ui app via systemd. See Thread '[GCE] For Noobs, Part 10 - Running Your B4J App As A Service and Automatically Starting At Boot' https://www.b4x.com/android/forum/t...ice-and-automatically-starting-at-boot.85739/

 

[aeric]

but using a script, I can run multiple instances like:

#!/bin/bash
cd /home/b4j/app1
nohup /usr/bin/java -jar app1.jar > app1.out &
cd /home/b4j/app2
nohup /usr/bin/java -jar app2.jar > app2.out &
cd /home/b4j/app3
nohup /usr/bin/java -jar app3.jar > app3.out &

 

[peacemaker]

using a script

Just for ref: strange, but i still cannot use Bash script, always error "command not found"

 

[aeric]

startup.sh: command not found

by the way, if you are not using crontab but to manuallly run, then I think the command is :

$ sh startup.sh

or

$ ./startup.sh

 

[peacemaker]

$ sh startup.sh

Yes, it works, but again strange that 2 instances of Java (excepting auto-java process), after run the .sh script:

If to kill any of these processes - all are killed.

 

[teddybear]

Yes, it works, but again strange that 2 instances of Java (excepting auto-java process), after run the .sh script:
View attachment 133553
If to kill any of these processes - all are killed.

I don't know how you write handler(webserver). that 2 instances are child processes forked by result.jar(pid is 25886, ppid is 1) you can see pid and ppid, usually, that's because there are clients connected to the webserver.
also you can use ps -ef|grep java|grep -v grep to filter the auto java

 

[OliverA]

but using a script, I can run multiple instances

Yes, as long as you're ok of not using systemd commands to control (start / stop / restart / etc) the individual instances.

 

[peacemaker]

https://www.b4x.com/android/forum/t...ice-and-automatically-starting-at-boot.85739/

SOLVED: at last helped this https://www.b4x.com/android/forum/threads/linux-web-app-autostart.142854/post-905176, but with WorkingDirectory=/work/www/myunit

[Unit]
Description=sc4 Service
After=network.target

[Service]
Type=simple
WorkingDirectory=/home/vlad/web/scat.team
ExecStart=/home/vlad/web/scat.team/jdk-14.0.1/bin/java -jar /home/vlad/web/scat.team/result.jar
SuccessExitStatus=143

Restart=on-abort

[Install]
WantedBy=multi-user.target