--- layout: "docs" page_title: "Basic Usage - Docker Provider" sidebar_current: "providers-docker-basics" description: |- The Docker provider in Vagrant behaves just like any other provider. If you are familiar with Vagrant already, then using the Docker provider should be intuitive and simple. --- # Docker Basic Usage The Docker provider in Vagrant behaves just like any other provider. If you are familiar with Vagrant already, then using the Docker provider should be intuitive and simple. The Docker provider _does not_ require a `config.vm.box` setting. Since the "base image" for a Docker container is pulled from the Docker Index or built from a Dockerfile, the box does not add much value, and is optional for this provider. ## Docker Images The first method that Vagrant can use to source a Docker container is via an image. This image can be from any Docker registry. An example is shown below: ```ruby Vagrant.configure("2") do |config| config.vm.provider "docker" do |d| d.image = "foo/bar" end end ``` When `vagrant up --provider=docker` is run, this will bring up the image `foo/bar`. This is useful for extra components of your application that it might depend on: databases, queues, etc. Typically, the primary application you are working on is built with a Dockerfile, or via a container with SSH. ## Dockerfiles Vagrant can also automatically build and run images based on a local Dockerfile. This is useful for iterating on an application locally that is built into an image later. An example is shown below: ```ruby Vagrant.configure("2") do |config| config.vm.provider "docker" do |d| d.build_dir = "." end end ``` The above configuration will look for a `Dockerfile` in the same directory as the Vagrantfile. When `vagrant up --provider=docker` is run, Vagrant automatically builds that Dockerfile and starts a container based on that Dockerfile. The Dockerfile is rebuilt when `vagrant reload` is called. ## Synced Folders and Networking When using Docker, Vagrant automatically converts synced folders and networking options into Docker volumes and forwarded ports. You do not have to use the Docker-specific configurations to do this. This helps keep your Vagrantfile similar to how it has always looked. The Docker provider does not support specifying options for `owner` or `group` on folders synced with a docker container. Private and public networks are not currently supported. ## Host VM On systems that cannot run Linux containers natively, such as Mac OS X or Windows, Vagrant automatically spins up a "host VM" to run Docker. This allows your Docker-based Vagrant environments to remain portable, without inconsistencies depending on the platform they are running on. Vagrant will spin up a single instance of a host VM and run multiple containers on this one VM. This means that with the Docker provider, you only have the overhead of one virtual machine, and only if it is absolutely necessary. By default, the host VM Vagrant spins up is [backed by boot2docker](https://github.com/mitchellh/vagrant/blob/master/plugins/providers/docker/hostmachine/Vagrantfile), because it launches quickly and uses little resources. But the host VM can be customized to point to _any_ Vagrantfile. This allows the host VM to more closely match production by running a VM running Ubuntu, RHEL, etc. It can run any operating system supported by Vagrant.
Synced folder note: Vagrant will attempt to use the "best" synced folder implementation it can. For boot2docker, this is often rsync. In this case, make sure you have rsync installed on your host machine. Vagrant will give you a human-friendly error message if it is not.
An example of changing the host VM is shown below. Remember that this is optional, and Vagrant will spin up a default host VM if it is not specified: ```ruby Vagrant.configure("2") do |config| config.vm.provider "docker" do |d| d.vagrant_vagrantfile = "../path/to/Vagrantfile" end end ``` The host VM will be spun up at the first `vagrant up` where the provider is Docker. To control this host VM, use the [global-status command](/docs/cli/global-status.html) along with global control.