REST Client not sending headers from shared configKey

[jburkal]

Describe the bug

When multiple REST Client classes uses the same value for configKey in their @RegisterRestClient annotation, headers specified in application.properties (using the quarkus.rest-client."client".headers."header-name" format) are no longer sent for all of the clients.

Expected behavior

Headers specified in the configuration of a specific REST client, e.g.:

quarkus.rest-client."testClient".headers."My-Header"=Test Header

should be sent on requests from all classes annotated with @RegisterRestClient(configKey = "testClient")

Actual behavior

Since Quarkus 3.17.0, the headers are only sent for one of the REST client classes.

It works as expected in both Quarkus 3.15.2 and 3.16.4.

How to Reproduce?

Reproducer: https://github.com/jburkal/quarkus-rest-header-test

Running the application (./mvnw quarkus:dev) with Quarkus 3.15.2 or 3.16.4 produces log lines such as:

DEBUG [org.jbo.res.rea.cli.log.DefaultClientLogger] Request: GET https://stage.code.quarkus.io/api/extensions?id=quarkus-rest-client Headers[My-Header=Test Header User-Agent=Test User Agent], Empty body
DEBUG [org.jbo.res.rea.cli.log.DefaultClientLogger] Request: GET https://stage.code.quarkus.io/api/streams Headers[My-Header=Test Header User-Agent=Test User Agent], Empty body

whereas with Quarkus 3.17.0 and newer, it looks like this:

DEBUG [org.jbo.res.rea.cli.log.DefaultClientLogger] Request: GET https://stage.code.quarkus.io/api/extensions?id=quarkus-rest-client Headers[My-Header=Test Header User-Agent=Test User Agent], Empty body
DEBUG [org.jbo.res.rea.cli.log.DefaultClientLogger] Request: GET https://stage.code.quarkus.io/api/streams Headers[User-Agent=Test User Agent], Empty body

Note that the second request no longer contains the "My-Header" header.

Output of uname -a or ver

No response

Output of java -version

No response

Quarkus version or git rev

3.17.0

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

No response

[quarkus-bot]

/cc @cescoffier (rest-client), @geoand (rest-client), @radcortez (config)

[radcortez]

For now, please use the FQN of the REST Client to set up the configuration.