Usage of source path attribute for bestpath calculation for imported paths

[soumyar-roy]

When a BGP route is leaked from source VRF foo to destination VRF bar, a route-map can be configured to strip off AS path attributes during the import process. Consider a scenario, a route in VRF foo has an AS path length of 5 hops. After the route-map strips certain ASes during the leak to VRF bar, the resulting route/path has an AS path length of 1 hop. The problem occurs during bestpath selection in VRF bar when comparing this leaked route/path against a remote route/path (also imported into VRF bar) with an AS path length of 3 hops. Instead of using the current AS path length of 1 hop from the leaked route's attributes in VRF bar, the bestpath algorithm traverses back to the parent route in source VRF foo and uses its original AS path length of 5 hops for comparison. The comparison becomes 5 hops versus 3 hops, causing the leaked route to lose even though its actual AS path in VRF bar is only 1 hop. This results in suboptimal routing .

Using attribute from source path, was introduced via following commit:
Behavior was introduced via commit da0c0ef
Author: Kantesh Mundaragi <kmundaragi@vmware.com>
Date: Mon Jun 8 14:40:17 2020 -0700

Need help to clarify following points:

1. Rather than unconditionally using source path attribute during best path calculation in destination VRF(bar), can we do it under a configuration?

2)If we agree to introduce a new configuration, say under BGP, then what should the behavior of the config
a) the configuration enables usage of source path attribute, rather than local/imported path's attributes, in destination vrf(bar) and name the config something like "bgp bestpath use src attrs" (so default behavior is to use local/imported path's attributes)
or
b) the configuration enables usage of destination/current path(imported path) attribute in destination vrf(bar) and name the config something like "bgp bestpath use dst attrs" (so default behavior is to use source path's attributes)

Note: current default behavior is to use source path's attributes, which aligns with 2.b. But In my opinion, 2.a is the right way, i.e. if the changes for "da0c0ef70cfb413450539581de2508fb6a385fc3" is done today, it should be done in line with 2.a

3)Based upon 2 what should be default data center profile.

Note:
impact after da0c0ef:
Attributes not Impacted (always use destination VRF):
Weight
LOCAL_PREF
ACCEPT_OWN community
AIGP
IGP Metric
LOCAL_ROUTE type
Path flags (SELECTED, STALE)

Attributes Impacted ((always use source VRF):
AS_PATH (the main problem!)
Origin
MED
Peer Type
CLUSTER_LIST
Router-ID/ORIGINATOR_ID
All peer-related comparisons