MutableContentMetadata.setContentType? But Jenkins has no API for detecting content type of files.

Ideally VirtualFile.toExternalURL would allow you to pass a “view mode” parameter requesting a content type…if S3 supports that.

RobustHttpClient.uploadFile also has no way of setting a content type, which is another blocker for this I think?

(this is actually a blocker for our team to use this plugin, "I can't see my test report when I click the link ")

I doubt RobustHttpClient is involved; the content type setting would be done on the master side using the AWS SDK. I think. Will not know for sure until a fix is implemented. Perhaps dcurrie wants to take a stab at it?

Unless I'm reading wrong, by https://github.com/jenkinsci/artifact-manager-s3-plugin/blob/master/src/main/java/io/jenkins/plugins/artifact_manager_jclouds/JCloudsArtifactManager.java#L115 and https://github.com/jenkinsci/artifact-manager-s3-plugin/blob/master/src/main/java/io/jenkins/plugins/artifact_manager_jclouds/JCloudsArtifactManager.java#L134, it works by getting a presigned S3 url and `uploadFile`ing to it with RobustHttpClient.

My reading is the same as akdor1154. The S3 API indicates that the default Content-Type on a PUT is binary/octet-stream unless you specify otherwise.

Right, the question is whether the URL itself can encode the desired content type or whether this needs to be handled as an HTTP header by the uploading code. In the latter case, RobustHttpClient.uploadFile would need to be amended to set a header.

(Then the next question is what content type to pick. Files.probeContentType seems like the right choice.)