Spring Boot + OpenShift + Auto-Reconfiguration

I wanted to know how easy it would be to get Spring-Boot auto-reconfiguration to work in OpenShift. It did not really work for me in Cloud Foundry without some massaging ( auto re-config blog ).

The proper way would be to extend https://github.com/spring-projects/spring-cloud/tree/master/spring-cloud-core for OpenShift Which is probably dead simple, too, but I wanted to do a quick 30 minute hack which become about a 90 minutes dirty hack.

In simple terms, the cartridge always sets -Dspring.profiles.active=cloud (unless this is overwritten by the app developer). And when it finds a ‘OPENSHIFT_MYSQL_DB_URL’ environment variable (which means the user added that service (cartridge) to the application, then the cartridge will add a the MariaDB (MySQL) information to ‘VCAP_SERVICES’ In addition I als set ‘VCAP_APPLICATION’ to some partially correct values, as well as VCAP_APP_HOST and VCAP_APP_PORT.

Then I deployed the jar generated from the unfamous-quotes cloud-foundry-autoreconfig-tests branch and it correctly picked up the MySQL DB and SUCCESS.

It was ridiculously easy to get that working in OpenShift. If I hadn’t put in a typo in one of my first attempts it would have been even easier.

What I did not mentioned in the last blog was that the version of the “unfamous quotes” code only works on Cloud Foundry if there is a data source supplied by Cloud Foundry. Otherwise you get:

org.springframework.cloud.CloudException: No unique service matching interface javax.sql.DataSource found. Expected 1, found 0

This happens due to the this code in DataSourceConfiguration:

return connectionFactory().dataSource();    

With the current version of the spring runner cartridge the same happens: You have to add a MariaDB or it wont work.

Since this was just a quick and dirty test, I did not add any other DB services. But I also would rather check out the spring-core-cloud and create an OpenShift Cloud Connector.