Add artefact browser

[michaelsauter]

Currently it is tricky to see artifacts as one has to login to Nexus to be able to access them.

To simplify this, we could add an endpoint to the pipeline manager which would allow users to browse artefacts.

It would work something like the following:

• Bitbucket build status / insight would link to an endpoint on the pipeline manager
• OpenShift OAuth proxy is deployed as a sidecar, protecting the endpoint
• User following the link needs to authenticate via the OAuth proxy (using OpenShift)
• When the endpoint receives a request, it searches for all assets in Nexus and displays them on screen
• When a request to one of the files is made, the endpoint proxies the request to Nexus, using the Nexus credentials stored in the K8s secret for access

The feature should be optional as the OpenShift proxy would not work in plain K8s clusters.

FYI @oalyman

[oalyman]

As a first step it maybe even sufficient to just provide the artifacts as is for proxied download.
Later ofc it would be nice if for instances zipped html test reports (e.g the gradle report) would be provided as an html page.
A link in the build log to the respective endpoint would be good.

[michaelsauter]

When the endpoint receives a request, it searches for all assets in Nexus and displays them on screen

This is not going to be so easy, as there is no easy way to know in which repository artifacts are stored. The repository depends on the finish task parameters.