ability to update request data upon successful deploy

[ssalinas]

Currently, if you want to change the scale of a service (or any other request-level setting) as well as deploy new code, you need to do this in two separate steps. This PR adds an optional newRequestData field to the SingularityDeployRequest. If present, it will be added to the pending deploy so that the scheduler and deploy checker will use this new request data for the new deploy. If the deploy succeeds the request is then updated. No other updates to request data are allowed if there is currently a pending deploy that also updates request data.

@tpetr @wsorenson

[tpetr]

naming seems a little awkward in my opinion -- updatedRequest might make more sense

[ssalinas]

yeah, went back and forth on the name like 10 times already. Open to changing for sure, updatedRequest sounds good

[ssalinas]

@tpetr updated the field names and such here. Took another look and I didn't see any more places where we would get conflicts between the two sources of request data.

• deploy checker -> uses the new request data if it is set when checking the deploy
• scheduler -> uses the pending deploy request data if it is set and if the pending request has a matching deploy id
• cleaner -> relevant cases only deal with the active deploy, so it always should use the current request data not pending deploy one

Would like to get @wsorenson 's thoughts as well to make sure I'm not missing anything.

[tpetr]

What are your thoughts on moving the updatedRequest field from SingularityDeployParent to SingularityDeploy? I'm trying to debug a possible issue with this PR and it's a pain to not be able to get the updated request data over the API.

[ssalinas]

My initial concern was that we then have possibly stale request data that hangs around and isn't correct. The deploy data is saved in history, but if the request is updated, we have out of date data hanging around. The deploy parent data is only around during the time the deploy is actually running as part of the pending deploy.

[ssalinas]

@tpetr after the update we made back in April this has been stable, good to merge?

[tpetr]

LGTM