How to deploy SpringBoot Maven application with Jenkins ? - maven

Question

I have a Spring Boot application which runs on embedded Tomcat servlet container mvn spring-boot:run . And I don’t want to deploy the project as separate war to standalone Tomcat.
Whenever I push code to BitBucket/Github, a hook runs and triggers Jenkins job (runs on Amazon EC2) to deploy the application.
The Jenkins job has a post build action: mvn spring-boot:run, the problem is that the job hangs when post build action finished.
There should be another way to do this. Any help would be appreciated.

Answer 1

The problem is that Jenkins doesn't handle spawning child process from builds very well. Workaround suggested by #Steve in the comment (nohuping) didn't change the behaviour in my case, but a simple workaround was to schedule app's start by using the at unix command:
> echo "mvn spring-boot:run" | at now + 1 minutes
This way Jenkins successfully completes the job without timing out.
If you end up running your application from a .jar file via java -jar app.jar be aware that Boot breaks if the .jar file is overwritten, you'll need to make sure the application is stopped before copying the artifact. If you're using ApplicationPidListener you can verify that the application is running (and stop it if it is) by adding execution of this command:
> test -f application.pid && xargs kill < application.pid || echo 'App was not running, nothing to stop'

Answer 2

I find very useful to first copy the artifacts to a specified area on the server to keep track of the deployed artifacts and not to start the app from the jenkins job folder. Then create a server log file there and start to listening to it on the jenkins window until the server started.
To do that I developed a small shell script that you can find here
You will also find a small article explaining how to configure the project on jenkins.
Please let me know if worked for you. Thnaks

Answer 3

The nohup and the at now + 1 minutes didn't work for me.
Since Jenkins was killing the process spun in the background, I ensured the process to not be killed by setting a fake BUILD_ID to that Jenkins task. This is what the Jenkins Execute shell task looks like:
BUILD_ID=do_not_kill_me
java -jar -Dserver.port=8053 /root/Deployments/my_application.war &
exit
As discussed here.

Answer 4

I assume you have a Jenkins-user on the server and this user is the owner of the Jenkins-service:
log in on the server as root.
run sudo visudo
add "jenkins ALL=(ALL) NOPASSWD:ALL" at the end (jenkins=your Jenkins-user)
Sign In in Jenkins and choose your jobs and click to configure
Choose "Execute Shell" in the "Post build step"
Copy and paste this:
service=myapp
if ps ax | grep -v grep | grep -v $0 | grep $service > /dev/null
then
sudo service myapp stop
sudo unlink /etc/init.d/myapp
sudo chmod +x /path/to/your/myapp.jar
sudo ln -s /path/to/your/myapp.jar /etc/init.d/myapp
sudo service myapp start
else
sudo chmod +x /path/to/your/myapp.jar
sudo ln -s /path/to/your/myapp.jar /etc/init.d/myapp
sudo service myapp start
fi
Save and run your job, the service should start automatically.

Answer 5

This worked for me on jenkins on a linux machine
kill -9 $(lsof -t -i:8080) || echo "Process was not running."
mvn clean compile
echo "mvn spring-boot:run" | at now + 1 minutes
In case no process on 8080 it will print the message and will continue.
Make sure that at is installed on your linux machine. You can use
sudo apt-get install at
to install at