Unable to generate difference from liquibase gradle plugin

Question

I'm trying to implement liquibase in an existing SpringBoot project with MYSQL database. I want to be able to generate changesets which specify the differences when an entity is changed.

What I've done:

I've added liquibase dependencies and the gradle liquibase plugin in my build.gradle file. After making a domain change, I've run gradle generateChangeLog. The command executes successfully but nothing happens.

I read somewhere that this gradle plugin works only for the inmemory h2 database? Is that true? If yes then what alternative should I use to generate changelogs automatically.

I could not find a working SpringBoot gradle based example which uses MYSQL and has liquibase implemented WITH automatic change generation ability. It would be great if someone could provide that.

References:

https://github.com/stevesaliman/liquibase-workshop

https://github.com/liquibase/liquibase-gradle-plugin

Answer 1

The solutions is to write a gradle task which invokes liquibase diffChangeLog

Create a liquibase.gradle file in the project root directory, add liquibase-hibernate extension and write a gradle task that invokes the liquibase diffChangeLog command.

configurations {
  liquibase
}

dependencies {
  liquibase group: 'org.liquibase.ext', name: 'liquibase-hibernate4', version: 3.5
}

//loading properties file.
Properties liquibaseProps = new Properties()
liquibaseProps.load(new FileInputStream("src/main/resources/liquibase-task.properties"))

Properties applicationProps = new Properties()
applicationProps.load(new FileInputStream("src/main/resources/application.properties"))

task liquibaseDiffChangelog(type: JavaExec) {
  group = "liquibase"


  classpath sourceSets.main.runtimeClasspath
  classpath configurations.liquibase
  main = "liquibase.integration.commandline.Main"

  args "--changeLogFile=" + liquibaseProps.getProperty('liquibase.changelog.path')+ buildTimestamp() +"_changelog.xml"
  args "--referenceUrl=hibernate:spring:" + liquibaseProps.getProperty('liquibase.domain.package') + "?dialect=" + applicationProps.getProperty('spring.jpa.properties.hibernate.dialect')
  args "--username=" + applicationProps.getProperty('spring.datasource.username')
  args "--password=" + applicationProps.getProperty('spring.datasource.password')
  args "--url=" + applicationProps.getProperty('spring.datasource.url')
  args "--driver=com.mysql.jdbc.Driver"
  args "diffChangeLog"
}

def buildTimestamp() {
  def date = new Date()
  def formattedDate = date.format('yyyyMMddHHmmss')
  return formattedDate
}

NOTE: I have used properties files to pass arguments to the liquibase command, you could add the values directly, but that would not be a good practice.

Next, you would need to apply the liquibase.gradle file from within the project's build.gradle file. and add the liquibase dependency

apply from: 'liquibase.gradle'
//code omitted
dependencies {
    compile (group: 'org.liquibase', name: 'liquibase-core', version: "3.4.2")
}

After this step liquibase would be setup completely.

You can now use gradle liquibaseDiffChangeLog to generate changelogs.