Support for main class detection in "gradle installApp"

[sukrit007]

Given : A Spring boot project (v1.1.1) integrated with gradle

When: I run

./gradlew clean build install

Then: My build fails with exception :

:startScripts FAILED
FAILURE: Build failed with an exception.
* What went wrong:
A problem was found with the configuration of task ':startScripts'.
> No value has been specified for property 'mainClassName'.

When: I change version of spring boot to 1.0.2 and run the same command

Then: My build passes and installs my application in build/install folder.

[dsyer]

It's a nasty failure I agree (so maybe we can work out why it is coming out that way), but the "install" task needs some configuration AFAIK anyway. This works for me

buildscript {
    repositories {
        mavenLocal()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${project.bootVersion}")
    }
}

apply plugin: 'java'
apply plugin: 'maven'
apply plugin: 'spring-boot'

group = 'installer'
version = '0.0.0'

install {
    repositories.mavenInstaller {
        pom.project {
          parent { 
            groupId 'org.springframework.boot'
            artifactId 'spring-boot-starter-parent'
            version "${project.bootVersion}"
          }
        }
    }
}

jar {
    baseName =  'installer'
}

repositories {
    mavenLocal()
    mavenCentral()
}

dependencies {
    compile "org.springframework.boot:spring-boot-starter"
}

What were you using?

[sukrit007]

Actually I was not using maven installer.

There was a install task available as part of boot . When I ran it in 1.0.2, it created a folder structure

build/install/{my_app}/bin : Shell File that started spring boot
build/install/{my_app}/lib : All depedencies present here

When I ran same logic in 1.1.1 , this did not work. After applying maven plugin , it only publishes artifact to maven repo but I am not seeing the same behavior has 1.1.1 .

[sukrit007]

Here is my boot config

buildscript {
    ext {
        springBootVersion = '1.1.1.RELEASE'
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath 'org.kt3k.gradle.plugin:coveralls-gradle-plugin:0.4.0'
        classpath 'org.springframework:springloaded:1.2.0.RELEASE'
    }

    repositories {
        mavenLocal()
        mavenCentral()
    }

}
apply plugin: 'jacoco'
apply plugin: 'coveralls'
apply plugin: 'groovy'
apply plugin: 'spring-boot'
apply plugin: 'eclipse'
apply plugin: 'idea'

project.with {
    sourceCompatibility = '1.8'
    targetCompatibility = '1.8'
    group = 'com.xyz.abc'
}

jar {
    baseName = 'xyz-server'
    version =  rootProject.version
}
jacoco {
    toolVersion = "0.7.1.201405082137"
}

jacocoTestReport {
    reports {
        xml.enabled = true // coveralls plugin depends on xml format report
        html.enabled = true
    }
}
task wrapper(type: Wrapper) {
    gradleVersion = '1.12'
}

repositories {
    mavenCentral()
}

configurations {
    providedRuntime
}



dependencies {
    //Groovy
    compile("org.codehaus.groovy:groovy-all:2.3.2")

    // tag::jetty[]
    compile("org.springframework.boot:spring-boot-starter-web") {
        exclude module: "spring-boot-starter-tomcat"
    }
    compile "org.springframework.boot:spring-boot-starter-jetty"
    compile "org.eclipse.jetty:jetty-webapp:9.+"
    compile "org.eclipse.jetty:jetty-jsp:9.+"

    compile "org.springframework.boot:spring-boot-starter-security"
    compile "org.springframework.security.oauth:spring-security-oauth2:2.0.1.RELEASE"
    compile "org.springframework.security:spring-security-jwt:1.0.+"

.....Other dependencies.......
}

[dsyer]

Hmm. I don't know how that "install" task gets added (nothing to do with Boot), but it looks like a synonym for the application plugin's "installApp" (it was renamed from "install" to "installApp" in Gradle 1.0 I believe, but apparently still works if the Maven plugin is not present). I'm not sure I want to know how that happens. I'll add a test and see if we can get it to work.

Update: I conclude that you must be using a really old version of gradle because "installApp" is the only thing that works for me without the Maven plugin. We can try and alert the application plugin that we know the mainClass (we already compute it in FindMainTask so I'll probably put it there).

P.S. a "workaround" is to specify the main class in the application plugin tasks that you use, e.g. like this:

startScripts {
  mainClassName = 'demo.Application'
}

[sukrit007]

Update:

1. Look like install was simply calling installApp (Gradle 1.12) w/o maven plugin.
2. I tried installApp using 1.0.2 (works) and 1.1.1 (Fails) and got similar behavior (As described earlier).
3. I tried with workaround posted :
   startScripts {
   mainClassName = 'demo.Application'
   }
   and it worked this time.

Thanks for all your help on this. The only thing that remains a mystery is why it worked on 1.0.2 and breaks in 1.1.1 (w/o the workaround)