CORSConfig is not representable as YAML

As seen during #4525 development, CORSConfig cannot be represented as YAML because we’d need the quarkus.http.cors key to be both the key of a key/value pair and the key of a dictionary, which is not possible.

A properties-based CORS filter configuration currently looks like this:

quarkus.http.cors=true
quarkus.http.cors.origins=http://foo.com,http://www.bar.io
quarkus.http.cors.methods=GET,PUT,POST
quarkus.http.cors.headers=X-Custom
quarkus.http.cors.exposed-headers=Content-Disposition
quarkus.http.cors.access-control-max-age=24H

We only need to change the quarkus.http.cors=true property to quarkus.http.cors.enabled=true to make it convertible to YAML.

[gwenneg]

Here’s the complete list of config keys that are currently not representable as YAML, based on the ALL CONFIGURATION OPTIONS doc page (I’m glad it existed to do this check!):

quarkus.hibernate-orm.database.generation
quarkus.hibernate-orm.database.generation.halt-on-error

^ quarkus.hibernate-orm.database.generation could be replaced with quarkus.hibernate-orm.database.generation.auto to match the original Hibernate property. @gsmet WDYT?

quarkus.hibernate-orm.dialect
quarkus.hibernate-orm.dialect.storage-engine

^ quarkus.hibernate-orm.dialect could be replaced with quarkus.hibernate-orm.dialect.name but it differs from the original Hibernate property. @gsmet WDYT?

quarkus.http.cors
quarkus.http.cors.origins
quarkus.http.cors.methods
quarkus.http.cors.headers
quarkus.http.cors.exposed-headers
quarkus.http.cors.access-control-max-age

^ quarkus.http.cors will become quarkus.http.cors.enabled

quarkus.log.console.async
quarkus.log.console.async.overflow
quarkus.log.console.async.queue-length

^ quarkus.log.console.async could be replaced with quarkus.log.console.async.enabled

quarkus.log.file.async
quarkus.log.file.async.overflow
quarkus.log.file.async.queue-length

^ quarkus.log.file.async could be replaced with quarkus.log.file.async.enabled

quarkus.log.syslog.async
quarkus.log.syslog.async.overflow
quarkus.log.syslog.async.queue-length

^ quarkus.log.syslog.async could be replaced with quarkus.log.syslog.async.enabled

I also noticed several configuration keys being used by quarkus-agroal, quarkus-reactive-mysql-client and quarkus-reactive-pg-client. I’m not sure that’s an issue though, but I’d like your opinion about it:

quarkus.datasource.max-size
quarkus.datasource.password
quarkus.datasource.url
quarkus.datasource.username

I’ll see if that kind of issue can be detected at build time, but I’m not sure it’ll be easy. Half of these cases were related to the use of @ConfigItem(name = ConfigItem.PARENT) and the other half was the consequence of hardcoded config keys names using @ConfigItem(name = "foo").

[gwenneg]

I like the idea. I guess this would have to be done in the YamlConfigSource that is currently being donated from micrprofile-extensions to smallrye-config, as discussed in #4525.

I’ll give empty YAML keys a try with #4525 as it is currently using the same YAML parser (snakeyaml) than the future smallrye-config version. It might already support empty keys.