How to log the active configuration in a Spring Boot application?

Question

I would really like to use YAML config for Spring Boot, as I find it quite readable and useful to have a single file showing what properties are active in my different profi

Answer 1

In case you want to get the active profiles before initializing the beans/application, the only way I found is registering a custom Banner in your SpringBootServletInitializer/SpringApplication (i.e. ApplicationWebXml in a JHipster application).

e.g.

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder)
{
    // set a default to use when no profile is configured.
    DefaultProfileUtil.addDefaultProfile(builder.application());
    return builder.sources(MyApp.class).banner(this::printBanner);
}

/** Custom 'banner' to obtain early access to the Spring configuration to validate and debug it. */
private void printBanner(Environment env, Class sourceClass, PrintStream out)
{
    if (env.getProperty("spring.datasource.url") == null)
    {
        throw new RuntimeException(
            "'spring.datasource.url' is not configured! Check your configuration files and the value of 'spring.profiles.active' in your launcher.");
    }
    ...
}