flowable-event-registry dependency on liquibase causes Spring Boot startup errors

[ilgrosso]

Due to this dependency https://github.com/flowable/flowable-engine/blob/master/modules/flowable-event-registry/pom.xml#L72-L75 I am receiving startup exceptions from my Spring Boot application:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'liquibase' defined in class path resource [org/springframework/boot/autoconfigure/liquibase/LiquibaseAutoConfiguration$LiquibaseConfiguration.class]: Invocation of init method failed; nested exception is liquibase.exception.ChangeLogParseException: Error parsing classpath:/db/changelog/db.changelog-master.yaml
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.3.RELEASE.jar:5.2.3.RELEASE]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:339) ~[spring-context-5.2.3.RELEASE.jar:5.2.3.RELEASE]

[filiphr]

We have the FlowableLiquibaseEnvironmentPostProcessor.

So if you are using our starters you should not be seeing this problem. Are you using our autoconfiguration or not? If you are, then which Spring Boot version are you using?

How are you configuring your Spring Boot Application?

If you are not using our starters or autoconfiguration then you will need to manually disable the Spring Boot Liquibase property:

• spring.liquibase.enabled on Spring Boot 2.x
• liquibase.enabled on Spring Boot 1.x

[ilgrosso]

Thanks for your answer.

Since Flowable is an optional module of Apache Syncope (the Spring Boot 2.2 application I am mentioning above) I would like to avoid "polluting" the main application.properties with specific properties as spring.liquibase.enabled, hence I decided to add the following bean definition to https://github.com/apache/syncope/blob/master/ext/flowable/flowable-bpmn/src/main/java/org/apache/syncope/core/flowable/WorkflowFlowableContext.java:

    @Bean
    public SpringLiquibase liquibase() {
        SpringLiquibase liquibase = new SpringLiquibase();
        liquibase.setShouldRun(false);
        return liquibase;
    }

For the moment, it seems to work.

[filiphr]

That's one option of doing it (this overrides the SpringLiquibase bean from Spring Boot).

You can also do something like the FlowableLiquibaseEnvironmentPostProcessor and set the property like we are doing. You can register that in the spring.factories of your flowable-bpmn module.

I am closing this issue now. If you think that there is something that we can do about it, please let us know.

[filiphr]

One other thing I forgot to add. If you are adding a bean then you would have to also add @AutoConfigureBefore(LiquibaseAutoConfiguration.class) in order to make sure that the bean from your WorkflowFlowableContext is scanned before the one from Spring Boot

[ilgrosso]

Understood, thanks.
Not sure if you can add somewhere in the docs / upgrade guide the need of disabling Liquibase.

[ilgrosso]

At the end I went through the FlowableLiquibaseEnvironmentPostProcessor path: apache/syncope@74f539b