Handle tags in ASG correctly

[shrinandj]

Is this a BUG REPORT or FEATURE REQUEST?: BUG REPORT

What happened: Upgrade-manager currently only checks whether an Instance's launchconfig or launch template matches with the one in the ASG. It does not check if the tags on the ASG match the tags on the instance.

If the user updated tags on the ASG, there may be no update to the launch config. However, if the tags have to be propagated to all instances in the ASG, it will require a rolling upgrade.

What you expected to happen: RollingUpgrade should check for launch-config/launch-template or tags in deciding whether an instance should be terminated or not. This will handle the case where changes to an ASGs tags will result in nodes being restacked with the correct tags.

Note that this should only be for tags which are supposed to be propagated to the nodes.

How to reproduce it (as minimally and precisely as possible):

• Create an ASG
• Ensure that nodes are up and running in the ASG
• Add a new tag to the ASG
• Create a RollingUpgrade CR for the ASG

It can be noticed that the RollingUpgrade today does not terminate the nodes. Once this feature is implemented, the nodes will be terminated.

[uthark]

If launchconfiguration and launchtemplate are the same and only tags are changed, shouldn't then upgrade manager just update the tags?