Store application build metadata artifact for use by the status API

[mcduffie]

Make it easier to use the Gitlab API to know the source repo for a given Gitlab build

Create some sort of artifact from the build process that allows querying builds through the Gitlab API to allow determination of which build is associated with which APG request through that API.

Maybe simplistic implementation is writing all the inputs from the APG API request into a JSON or YAML file that can be access through the Gitlab API. Maybe also the Gitlab clone endpoint generates a unique identifier that it return with that request that gets passed along to the build process and written into the artifact. Could use system time and a hash function to generate the key.

[GodwinShen]

@mcduffie and @edwinsarkissian ping for status.

[edwinsarkissian]

No work done on this yet.