To Docker or to Vagrant, an eternal struggle for a dev-ops / smart people (like me!) who wants to automate stuff is a big life and death question! No seriously, I mean there are just 2 camps of people, one is hardcore docker supporters who want docker everywhere (without realizing that docker is not a full virtualization solution but uses Linux kernel’s namespaces and cgroups functionality. So what does it mean? Well for starters, anything that requires mounting operations inside the docker container, for instance, requires special privileged access and these have the possibility to change your actual host filesystem (eg: mounting filesystems inside the container will mount it indirectly on your host as well and rest is history. It is not just mount operations, simple things like socket access, changes to locale or local-gen will not work inside docker containers without passing special access privilege flags while running the docker container.