Basic Usage of Provisioners
While Vagrant offers multiple options for how you are able to provision your machine, there is a standard usage pattern as well as some important points common to all provisioners that are important to know.
Options
Every Vagrant provisioner accepts a few base options. The only required option is what type a provisioner is:
name(string) - The name of the provisioner. Note: if notypeoption is given, this option must be the type of provisioner it is. If you wish to give it a different name you must also set thetypeoption to define the kind of provisioner.type(string) - The class of provisioner to configure. (i.e."shell"or"file")before(string or symbol) - The exact name of an already defined provisioner that this provisioner should run before. If defined as a symbol, its only valid values are:eachor:all, which makes the provisioner run before each and every root provisioner, or before all provisioners respectively.after(string or symbol) - The exact name of an already defined provisioner that this provisioner should run after. If defined as a symbol, its only valid values are:eachor:all, which makes the provisioner run after each and every root provisioner, or before all provisioners respectively.communicator_required(boolean) - Specifies the machine must be accessible by Vagrant in order to run the provisioner. If set to true, the provisioner will only run if Vagrant can establish communication with the guest. If set to false the provisioner will run regardless of Vagrant's ability to communicate with the guest. Defaults to true.
More information about how to use before and after options can be read below.
Configuration
First, every provisioner is configured within your
Vagrantfile
using the config.vm.provision method call. For example, the Vagrantfile
below enables shell provisioning:
Every provisioner has a type, such as "shell", used as the first
parameter to the provisioning configuration. Following that is basic key/value
for configuring that specific provisioner. Instead of basic key/value, you
can also use a Ruby block for a syntax that is more like variable assignment.
The following is effectively the same as the prior example:
The benefit of the block-based syntax is that with more than a couple options it can greatly improve readability. Additionally, some provisioners, like the Chef provisioner, have special methods that can be called within that block to ease configuration that cannot be done with the key/value approach, or you can use this syntax to pass arguments to a shell script.
The attributes that can be set in a single-line are the attributes that
are set with the = style, such as inline = "echo hello" above. If the
style is instead more of a function call, such as add_recipe "foo", then
this cannot be specified in a single line.
Provisioners can also be named (since 1.7.0). These names are used cosmetically for output as well as overriding provisioner settings (covered further below). An example of naming provisioners is shown below:
Naming provisioners is simple. The first argument to config.vm.provision
becomes the name, and then a type option is used to specify the provisioner
type, such as type: "shell" above.
Running Provisioners
Provisioners are run in three cases: the initial vagrant up, vagrant provision, and vagrant reload --provision.
A --no-provision flag can be passed to up and reload if you do not
want to run provisioners. Likewise, you can pass --provision to force
provisioning.
The --provision-with flag can be used if you only want to run a
specific provisioner if you have multiple provisioners specified. For
example, if you have a shell and Puppet provisioner and only want to
run the shell one, you can do vagrant provision --provision-with shell.
The arguments to --provision-with can be the provisioner type (such as
"shell") or the provisioner name (such as "bootstrap" from above).
Run Once, Always or Never
By default, provisioners are only run once, during the first vagrant up
since the last vagrant destroy, unless the --provision flag is set,
as noted above.
Optionally, you can configure provisioners to run on every up or
reload. They will only be not run if the --no-provision flag is
explicitly specified. To do this set the run option to "always",
as shown below:
You can also set run: to "never" if you have an optional provisioner
that you want to mention to the user in a "post up message" or that
requires some other configuration before it is possible, then call this
with vagrant provision --provision-with bootstrap.
If you are using the block format, you must specify it outside of the block, as shown below:
Multiple Provisioners
Multiple config.vm.provision methods can be used to define multiple
provisioners. These provisioners will be run in the order they're defined.
This is useful for a variety of reasons, but most commonly it is used so
that a shell script can bootstrap some of the system so that another provisioner
can take over later.
If you define provisioners at multiple "scope" levels (such as globally in the configuration block, then in a multi-machine definition, then maybe in a provider-specific override), then the outer scopes will always run before any inner scopes. For example, in the Vagrantfile below:
The ordering of the provisioners will be to echo "foo", "baz", then "bar" (note the second one might not be what you expect!). Remember: ordering is outside in.
With multiple provisioners, use the --provision-with setting along
with names to get more fine grained control over what is run and when.
Overriding Provisioner Settings
Warning: Advanced Topic! Provisioner overriding is an advanced topic that really only becomes useful if you are already using multi-machine and/or provider overrides. If you are just getting started with Vagrant, you can safely skip this.
When using features such as multi-machine or provider-specific overrides, you may want to define common provisioners in the global configuration scope of a Vagrantfile, but override certain aspects of them internally. Vagrant allows you to do this, but has some details to consider.
To override settings, you must assign a name to your provisioner.
In the above, only "bar" will be echoed, because the inline setting overloaded the outer provisioner. This overload is only effective within that scope: the "web" VM. If there were another VM defined, it would still echo "foo" unless it itself also overloaded the provisioner.
Be careful with ordering. When overriding a provisioner in a sub-scope, the provisioner will run at that point. In the example below, the output would be "foo" then "bar":
If you want to preserve the original ordering, you can specify
the preserve_order: true flag:
Dependency Provisioners
Warning: Advanced Topic! Dependency provisioners are an advanced topic. If you are just getting started with Vagrant, you can safely skip this.
If a provisioner has been configured using the before or after options, it
is considered a Dependency Provisioner. This means it has been configured to
run before or after a Root Provisioner, which does not have the before or
after options configured.
Dependency provisioners also have two valid shortcuts:
:each and :all.
Note: As of 2.2.6, dependency provisioners cannot rely on other dependency provisioners and is considered a configuration state error in Vagrant. If you must order dependency provisioners, you can still order them by the order they are defined inside your Vagrantfile.
An example of these dependency provisioners can be seen below:
The result of running vagrant provision with a guest configured above: