CODEWITHSUNDEEP
tomcatgrailsgrails-3.0
Robin M
Robin M

Reputation: 664

Unable to remove Embedded Tomcat from Grails 3.0.7 Application war

I tried following the notes in the grails documentation and attempted to remove the embedded tomcat server when creating a war file for deployment.

However, even though in build.gradle I have :

...
dependencies {
compile "org.springframework.boot:spring-boot-starter-logging"
compile "org.springframework.boot:spring-boot-starter-actuator"
compile "org.springframework.boot:spring-boot-autoconfigure"
provided "org.springframework.boot:spring-boot-starter-tomcat"
compile "org.grails:grails-dependencies"
compile "org.grails:grails-web-boot"
...

The generated WAR file is of the same size as before amending compile to provided for org.springframework.boot:spring-boot-starter-tomcat.

While exploring the WAR file I am still seeing the following files:

spring-boot-starter-tomcat-1.2.5.RELEASE.jar tomcat-embed-core-8.0.23.jar tomcat-embed-el-8.0.23.jar tomcat-embed-logging-juli-8.0.23.jar tomcat-embed-websocket-8.0.23.jar

The question is, why is this happening?

Upvotes: 2

Views: 1608

Answers (2)

Robin M
Robin M

Reputation: 664

OK, it seems to work like this and it would be great if the Grails documentation was a little clearer on what's happening behind the scenes.

Scenario 1 : When creating a (production) war using grails war and compile "org.springframework.boot:spring-boot-starter-tomcat" ...

Unzipping/exploding the war file, I see Tomcat is embedded within WEB-INF lib folder (5 or more jars) with all the other required application jars and there is also a folder org/springframework containing what looks to be the class files required to launch the embedded Tomcat server.

Scenario 2 : When creating a (production) war using grails war and provided "org.springframework.boot:spring-boot-starter-tomcat" ...

The 5 or more Tomcat embedded jars are moved out of WEB-INF/lib and placed in WEB-INF/lib-provided. The org/springframework folder and it's contents are not included either.

Testing on a local installation, you can drop this 'scenario 2' version of the war file into the Tomcat web apps directory and the application deploys without a hitch (the lib-provided folder and it's tomcat embed jars presumably being ignored).

Finally, there is a another version of the war file created : appname.war.original

This war doesn't have the WEB-INF/lib-provided nor the org/springframework folder and is smaller in size (of course).

This war also deploys correctly.

Why the tomcat embed jars are included in scenario 2 at all baffles me but there you go....

There is a discussion on it here too :

https://jira.grails.org/browse/GRAILS-12078

In a way, the grails documentation is correct. You remove the embedded tomcat server by adding provided

It just still bundles the jars into a folder named lib-provided for some reason.

Hope this helps any else pondering the same problem.

Upvotes: 2

Michael B
Michael B

Reputation: 431

In build.gradle, add the following:

springBoot {
    providedConfiguration = "provided"
}

Honestly, I don't understand the inner workings, but I had the very same problem and this is what provided (no pun intended) the solution.

Upvotes: 1

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