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dockervagrantboot2dockerdocker-machine

If docker uses virtual machine to run on a mac then what is its advantage over vagrant?

So I have read this in many places that docker is faster and more efficient because it uses containers over VMs but when I downloaded docker on my mac I realized that it uses virtual box to run the containers. I believe on a linux machine docker doesn't need virtual box and can run on Linux Kernel. Is this correct ?

Back to original question. Is docker still faster/efficient because it uses a single VM to run multiple containers as opposed to Vargrant's new VM for every environment ?

Solution

  • I believe on a linux machine docker doesn't need virtual box and can run on Linux Kernel. Is this correct ?

    Yes, hence the need for a VirtualBox Linux VM (using a TinyCore distribution)

    Is docker still faster/efficient because it uses a single VM to run multiple containers as opposed to Vargrant's new VM for every environment ?

    Yes, because of the lack of Hypervisor simulating the hardware and OS: here you can launch multiple containers all using directly the kernel (through direct system calls), without having to simulate an OS.
    (Note: May 2018, gVisor is another option: a container, simulating an OS!)

    vm vs container

    See more at "How is Docker different from a normal virtual machine?".

    Of course, remember that Vagrant can use a docker provider.
    That means you don't have to always provision a full-fledged VM with Vagrant, but rather images and containers.

    Vagrant.configure("2") do |config|
  config.vm.provider "docker" do |d|
    d.image = "foo/bar"
  end
end

    See Vagrant docker provisioner.