[SONiC] SONiC Container Upgrade - Query

[Keerthi kumar thovi]

Hi Team,
   Please help to get the clarification on the below query regarding "SONiC container upgrade facility".
   
Query:
   1. As per general understanding of a docker-container concept, a user can upgrade/re-install any installed container and is permitted.
   2. SONiC Architecture is based on docker-containers concept.
   Then, a user should be allowed to upgrade/re-install any of the SONiC docker/container. But, in practice it is not permitted in SONiC for containers having their state as "Built-In" i.e. while using 'sonic-package-manager'.
   (Reference: https://github.com/sonic-net/sonic-utilities/blob/master/doc/Command-Reference.md#sonic-package-manager)

   Why do we have this restriction at container upgrade facility based on the state in SONiC NOS and what is the procedure to selectively upgrade any particular container instead of creating a new SONiC image. Please help.

Thanks and Regards,

T. Keerthi Kumar