I am not vagrant user... but what role can it play when my dev laptop is ubuntu for eg? Does it become redundant layer if all my virtualization,configuration and deployment needs are met by docker and dockerfile?
It depends on your perspective. Vagrant is billed as a manager of development environments. It has a well known and easy to use workflow for creating/modifying/destroying those environments (vagrant up/provision/destroy). With its Docker integration, it provides you with a nice management layer for managing those Docker development environments. You could achieve the same thing with Docker directly, but there would be some non-zero amount of work required to create your workflow commands and share that development environment with others (whereas with Vagrant you just need to share a Vagrantfile).
Here's an interesting Stack Overflow question related to this topic, http://stackoverflow.com/questions/16647069/should-i-use-vag.... Also, it looks like Docker is working to build out its own development environment tools using Fig, but that seems a bit nascent right now.
Here's an interesting Stack Overflow question related to this topic, http://stackoverflow.com/questions/16647069/should-i-use-vag.... Also, it looks like Docker is working to build out its own development environment tools using Fig, but that seems a bit nascent right now.