Support credentialhelper in remotetool

[daniel-sudz]

I'm trying to use remotetool and would like to auth with a credentialhelper in the same way that bootstrap/reclient auths using experimentalCredentialHelper: https://github.com/bazelbuild/reclient/blob/8594b39e9e3cff540a8c615716c4ad7d8a7b326b/cmd/bootstrap/main.go#L82. It is my current understanding that this is not possible to achieve. I'm looking for guidance around whether this is something being considered and/or if upstream would accept a PR for such a change.

[daniel-sudz]

@banikharbanda @gkousik I see some recent changes in #562 so was looking to tag for comments

[gkousik]

Thanks for the bug! There's two options here:

1. All of the remotetool functionality has also been added to reproxytool in re-client repository - https://github.com/bazelbuild/reclient/tree/main/cmd/reproxytool. The goal with adding it there was to improve the user-experience of finding and re-running actions directly from an RPL (reproxy-log-file) file that reproxy generates and prototype some options for a Web-based UI for doing the same (remotetool in this repository does NOT understand the RPL file format and we don't intend to make it understand that format either).

A side-effect of this is that with one more change to just add the credshelper flags to reproxytool, you can just use your own creds helper for authentication. I'll get this done in the next couple of days.

2. We are also implementing credshelper support directly in the SDK. So when that implementation is completed, remotetool would support credshelper auth mechanism as well.