How to deploy spring boot web application with configurable properties - java

After researching i learned that the common way to deploy spring boot web applications is as a war file.However,i have a project i made for a company,now i need to send them the project to try it out and they need to be able to configure the application.properties or to be specific the database location and credentials.so my question is do i need to deploy the project in a different way or is there a way to make the war file application properties modifiable later ?

Did you consider Spring Cloud Config Server
https://cloud.spring.io/spring-cloud-config/multi/multi__spring_cloud_config_server.html.
This is the most elegant way to configure and externalize your properties. If not I would strongly suggest incorporating that component. Plug the config server with your spring boot app without much coding and your application will be much more manageable and extensible.

Spring Boot applications are actually typically packaged as Uber jars with Tomcat embedded. You can accomplish this using spring-boot maven plugin or a similar gradle plugin if need be.
Once in this state the jar can be started normally and you can override configuration properties when invoking it.
java $JAVA_OPTS -Dspring.service.name=my-service -jar /my-service.jar
EDIT: This is not the only way you can solve this problem, and #piy26's answer is an excellent solution for injecting external configuration into an enterprise ready spring boot application. However for the case that your are describing you would need the company to set up there own configuration server, and whats more they will still have to override the configuration server location property so the application will pull properties from their config-server. For your example it seems you need the simplest way to override application properties within the jar.

Related

Spring boot embedded container or war file in an external container for production

I'm complete able to configure spring boot in both cases, the question here is which of them are more robust and is the more recommended, because I didn't find in the spring boot documentation the recommended way to deploy it in a production environment, my concerns about use the embedded container are:
If I want to set it as a Windows or Linux service, is the jar file the best option?
If I use the jar file I'm not going to have access to restart the server.
Maybe in the future I need more applications in the same container.
If I restart the machine I have to execute again the java -jar.
The question in general is which is better use the jar file and execute it as java -jar jarname.jar in production or change the packaging to war set the tomcat as provided and set the generated war in an empty tomcat.
I hope you can help me.
---EDIT---
Many times the answer is depends, this is for a normal web application or REST web service.
jar packaging is perfectly suitable for production and you should rather fallback to war only if you really have to - which is often the case when you cannot control your deployment environment (which is often the case in large enterprises).
There is a chapter in Spring Boot Reference about setting up Spring Boot based application as a Unix/Linux/Windows service: Installing Spring Boot applications.
Regarding your concern:
Maybe in the future I need more applications in the same container.
With embedded containers if you need more applications running on the same machine, you should start two applications separately, each running on different port and effectively you will end up with two containers running - which is good, applications are better isolated from each other.
About a month ago I had the question like yours.
Let me share my conclusion:
1) JAR:
You can run independently every appliction with different ports (in linux, java -jar ... > app_logs.log &) and you can route it (e.g. nginx). Note that, restarting is not problem. You can write custom bash script (like this: ps aux | grep appname and kill by PID)
But there are some problems with configuring production app. Property files will archived into jar.
2) WAR
You can deploy into container and just run it. Easy managing at the server. If you want to re-configure app, open properties file from unarchived folder inside container, change it as need and restart container. So, managing and configuring will be easy.
But, if you want to run another app in this server with another port, then you must install another copy of container and config it.
So, in my practice, using war app easier than jar to manage and re-configure.
I don't know that much about Windows services but on Linux you can add the execution of a jar to a RC-Scripts (and thus make the application start at a certain run-level). For a spring boot app you just have to symlink to the jar and you can start/stop/etc like any other service, see: Spring Boot application as a Service
restart the machine or the JVM? A shutdown mechanism is built into spring boot, you just have to activate it (and you should enable security machanism so that not anybody can do that), see: How to shutdown a Spring Boot Application in a correct way?
Spring-Boot enables microservices - so the idea is to have one embedded webapp-container for each webapp/microservice. This reduces the risk of losing all services when only one is going down.
Yes. and you have to execute catalina.sh|bat start after every restart. Or you add an appropriate startup script (see 1.)
I sense that you'd rather do it the old-fashioned way. Despite the 'matter of taste' answer, there is one argument pro-jar: the only dependency is the JVM! The rest (the web-app-container, db-drivers, other libraries) is all part of the package you deliver. And if you decide to change the container for the next release, so will it be.
One more reason to use "war" file in production.
Springboot masked an error Jetty threw whereas WAR deployed in Jetty correctly caught it ( though issue below is still under review )
https://github.com/spring-projects/spring-boot/issues/8917#issuecomment-294673487
I don't know much about server kind of things, But my recommendation is
If you are using Monolithic application, better to use war with
external tomcat.
If you are using for Micro Service applications, use embedded
tomcat with different port. And each micro service applications are
independent from each other.

Spring boot basic

Just started exploring spring boot and trying to understand.....
In a normal project scenario, we create multiple projects / modules depending on functionality. Ultimately, package all different jars , wars in .ear and deploy it.
With spring boot, new project are deployed on a separate of instances of tomcat.
But if all these projects are related, it will need reconciliation of proprty files and any other resources differently utilized, before you create .ear.
While I understand the advantages of spring boot while development, is there any thought on how to make this process better when using spring boot?
Modern cloud architectures are moving away from using property files. Your Ops or DevOps teams should appreciate if your app would accept configurations via system properties. Spring Boot is perfectly suited for that.
Older fashioned orchestrators would replace placeholders in your properties files during deployment phase.

How to run multiple Spring Boot applications easily on Production

I am trying to figure out an easy way to manage many Spring Boot applications on my Production server. Right now I have many fat jars running on different folders where each one has its your own script to start/stop the application and there's an external folder for the configurations (logback, properties, xml). For record those configurations are loaded by command line -Dloader.path to Spring Boot execution.
So how can I avoid conflicts for the same http/https port already running on Production? Does exist any kind of application manager where system administrators could control it? One solution I found was to virtualize Spring Boot applications with Docker, but my environment is Unix Solaris.
Is there any java solution for this scenario?
You can have a look at Spring Cloud which will give you better control and management when running multiple boot applications. All components of Spring Cloud
might not be useful to you, but few of them will help in port resolution, service rerouting and property maintenance. Along with the above you can also try SBA.
Along with the above you can also try Nginx for UI load balancing and reverse proxy.

Spring Boot external configuration on another server

We are migrating applications to spring boot and we came to conclusion that it would be good to shift all configuration file to external server. I wonder if spring boot is capable of reading configuration file from another server during startup? If this is possible how can I achieve it? Now I read all config data from app-config.yml but in future I would like to get ride of this file from war. Thanks for any answers.
Of course spring has such stuff in the toolbox:
http://cloud.spring.io/spring-cloud-config/
This would give you a central configuration server backed e.g. by a git repository holding the configuration.
Hope this is what you are looking for.
You can user Spring Cloud Config Server, it allows to share a properties folder via rest services.
In your application client include Spring Cloud Config Client dependency to property sources read those values from server.

Adding spring mvc to a spring java "desktop" application

I have a Java desktop application which uses spring framework and I need to replace the Swing UI with a web front end. I understand that I will need to adapt many things to make things work with the MVC architecture.
My concrete question is the following:
Will my application now have to run entirely in the application server?
I would appreciate if anyone could point me to some documentation that goes through a similar process.
Thanks!
Technically yes, but Spring Boot makes it trivial to set up an embedded servlet container and package your entire application as a runnable jar. This is how we're deploying our applications to production; the only thing we need is a JRE on the server VM, and java -jar takes care of all of it.
I recommend using Maven with the Spring Boot plugin (there's also a Gradle plugin) with the repackage goal, and using the lightweight Undertow servlet engine instead of the default Tomcat.

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