Question

How do I cleanly separate tasks that might require two different configuration tasks in Gradle? I’m attempting to separate the actual tasks that I want to execute in a buildSrc/dbhelpertasks.gradle file from the parent build.gradle file. build.gradle will contain partially configured tasks that are used in dbhelpertasks.gradle.

I have a number of different databases that I want to connect and execute SQL on so I created a SQLServerTask that takes a database name and URL.

Custom SQLServerTask.groovy

import org.gradle.api.DefaultTask
import org.gradle.api.tasks.TaskAction
import groovy.sql.Sql


class SQLServerTask extends DefaultTask {
    def hostname
    def database
    def port = 1433
    def username
    def password
    def sql
    def sqlServerDriver = 'net.sourceforge.jtds.jdbc.Driver'

    @TaskAction
    def executeSql() {
        url = hostname + ":" + port + "/" + database
        databaseConnProps = [user: username, password: password]
        def sqlInstance = Sql.newInstance(url, databaseConnProps, sqlServerDriver)
        println "I would execute " + sql
    }

}

I then created a task in my build.gradle that would configure the SQLServerTask with some of the properties.

build.gradle

import groovy.sql.Sql
apply from: 'buildSrc/dbhelpertasks.gradle'
repositories { 
    mavenCentral()
}

configurations {
    driver
}

dependencies {
    driver group: 'net.sourceforge.jtds', name: "jtds", version: "1.2.4"
}

//Load up all the drivers for use in this project
URLClassLoader loader = GroovyObject.class.classLoader
configurations.driver.each {File file ->
    loader.addURL(file.toURL())
}

task contentDbTask(type: SQLServerTask) {
    println "Configuring content db task"
    hostname = contentDbUrl
    database = contentDbName
    username = contentDbUserName
    password = contentDbPassword
}

The dbhelpertasks.gradle file contains the final configuration (SQL Statement) of the actual tasks that I want to execute.

buildSrc/dbhelpertasks.gradle

task getSiteParams(type: contentDbTask) {
    println "Configuring Site Params Task"
    sql = "SELECT * FROM CMS_SITE_PARAM"
}

When I execute gradle getSiteParams it ends up failing

* What went wrong:
A problem occurred evaluating script.
> Could not find property 'contentDbTask' on root project 'shipyard'.

Answer 1

There are a number of misconceptions here.

First, only class SQLServerTask should be in buildSrc, as the only purpose of buildSrc is to produce classes which are then used by the main build.

dbhelpertasks.grovvy would typically go into a top-level gradle directory (sibling of buildSrc) and end in .gradle. Preconfiguration of a task, like contentDbTask does, would typically be done by a plugin (like the dbhelpertasks.gradle script plugin) rather than a task.

A task’s type is always a class, so task getSiteParams(type: contentDbTask) won’t work. Also, dbhelpertasks.groovy can’t see tasks added (or any other configuraion done) by build.gradle, only the other way around. This is because the latter applies the former at the very top (which is fine).