Support `rollForward` value

[siewers]

Are there any plans to support the rollForward property in global.json?

If I set the version to 8.0.202 and rollForward to latestPatch, I would expect the script to install the (current) latest patch version 8.0.205, but that doesn't happen.

The same with the other values of the rollForward property.

[f-alizada]

Hello @siewers, thank you for raising the ticket!
@baronfel Could you please take a look at the suggestion?

[baronfel]

As a feature this makes sense, but I'm not sure that the existing redirect setup gives us the ability to actually handle all of the kinds of rollForward that exists today. I think to do this feature correctly we'd need to move to the releases json manifests as described in #463, but that involves a lot of json parsing that I'm loathe to do at the terminal.

[js6pak]

@baronfel

As a feature this makes sense, but I'm not sure that the existing redirect setup gives us the ability to actually handle all of the kinds of rollForward that exists today. I think to do this feature correctly we'd need to move to the releases json manifests as described in #463, but that involves a lot of json parsing that I'm loathe to do at the terminal.

As you can see in #472, the only two new redirects we would need is <major>.x for latestMinor and actually working latest regardless of STS/LTS for latestMajor.

[baronfel]

I think these requests all make sense, but we'd need to tag in @rbhanda and @leecow to make any changes to the redirect scheme. So we'd need to start with a public accounting of the current redirect scheme and document the new additions.

[leecow]

The idea seems sound. The redirect scheme was documented a while back by the former dev owner, so I expect @baronfel and @YuliiaKovalova would tackle that. With respect to releases.json size implications on #472, we're in the process of implementing improvements to the release notes json files to help with the file size issue (dotnet/core#9417).