Environment variables behaving differently within Quarkus extensions?

[Tomnivore]

It seems there's a disparency with how different extension in Quarkus read ENV file variables.
My examples are examples are quarkus-rest, quarkus-rest-client-oidc-filter and quarkus-logging-gelf.

If I do a service with @RegisterRestClient("my-client") QUARKUS_REST_CLIENT_MY_CLIENT_URL works directly (as long as there are no capital letters). This is how I expect it to work

However if put a @OidcClientFilter("my-oauth") QUARKUS_OIDC_CLIENT_MY_OAUTH_CLIENT_ID does not connect to the config without also declaring it in application.properties as quarkus.oidc-client.my-oauth.client-id.

Likewise QUARKUS_LOG_HANDLER_GELF_ADDITIONAL_FIELD_CUSTOM_FIELD_VALUE won't work without declaring quarkus.log.handler.gelf.additional-field.custom-field.value.

Is there a reason or is it an oversight? If it's an oversight is it something that could and would be fixed?

[phillip-kruger]

/cc @radcortez

[radcortez]

When you have something like QUARKUS_REST_CLIENT_MY_CLIENT_URL, where MY_CLIENT is a dynamic name, we cannot reliably determine only with this information if MY_CLIENT should be my-client (dash), my.client (dot), or even my_client (underscore): https://quarkus.io/guides/config-reference#environment-variables

Now, the REST Client config did work without having to declare the dotted version because it was just querying all possible combinations, which is not a desired behavior. See:

• Move REST Client configuration to use @ConfigMapping #42106
• Improve compatibility of the REST Client configuration #42932

Because we didn't want to remove that behaviour, we added some proper support for it with:

• Support a fixed list of Map keys statically @WithKeys smallrye/smallrye-config#1220
• Strict config lookup for the REST Client #43345

Such extensions like quarkus-rest-client-oidc-filter or quarks-logging-gelf must discover the names during build time and feed them to the config so we know which keys to look for. If not, the configuration would still need additional help by adding the exact name to a non-environment variable source to match it with its environment variable name.

[Tomnivore]

Thank you for the answer. Although it could be cool to be able to do all the stuff with ENVs, I understand your answer and it's reasonable. I will mark this question answered.