Customer's Requirement:
1. Their aim to avoid maintaining a single ImageSetConfiguration.
2. They want to ensure that the generated operator index does not include the entire catalogs.
3. They want the generated operator index to include only the catalogs of mirrored operators, even if these operators are mirrored by different ImageSetConfigurations at different times.
 

There should be a mechanism where if we use new imagesetconfig.yaml then oc-mirror should be smart enough to analyse already mirrored operators from index image available in private registry and mirror new operators with those.

For ex.,

When we mirror 100 operator's using oc-mirror it generates an index image which consist those 100 operator's details.  Now We want to mirror more 50 operators and Now I want to mention only  new 50 operators in Imageset file not the old 100 operators. And I want existing index image should be appended with new 50 operators.

How oc-mirror currently works:

If we mirrored operator-0 and operator-1 and now I want to mirror operator-3. So, if I mirror that operator without mentioning the operator-0 and operator-1 entries it will replace/prune the old entries with new one.

What feature needs to be added:

If oc-mirror is storing the metadata in registry then they should just mention the operator-3 in imageset file and after mirroring they should see operator-1, operator-2 and operator-3  all three operators are available.