Machine Readable Output

Every Vagrant command accepts a --machine-readable flag which enables machine readable output mode. In this mode, the output to the terminal is replaced with machine-friendly output.

This mode makes it easy to programmatically execute Vagrant and read data out of it. This output format is protected by our backwards compatibility policy. Until Vagrant 2.0 is released, however, the machine readable output may change as we determine more use cases for it. But the backwards compatibility promise should make it safe to write client libraries to parse the output format.

Advanced topic! This is an advanced topic for use only if you want to programmatically execute Vagrant. If you're just getting started with Vagrant, you may safely skip this section.

Work-In-Progress

The machine-readable output is very new (released as part of Vagrant 1.4). We're still gathering use cases for it and building up the output for each of the commands. It is likely that what you may want to achieve with the machine-readable output is not possible due to missing information.

In this case, we ask that you please open an issue requesting that certain information become available. We'll most likely add it!

Format

The machine readable format is a line-oriented, comma-delimeted text format. This makes it extremely easy to parse using standard Unix tools such as awk or grep in addition to full programming languages like Ruby or Python.

The format is:

timestamp,target,type,data...

Each component is explained below:

  • timestamp is a Unix timestamp in UTC of when the message was printed.

  • target is the target of the following output. This is empty if the message is related to Vagrant globally. Otherwise, this is generally a machine name so you can relate output to a specific machine when multi-VM is in use.

  • type is the type of machine-readable message being outputted. There are a set of standard types which are covered later.

  • data is zero or more comma-separated values associated with the prior type. The exact amount and meaning of this data is type-dependent, so you must read the documentation associated with the type to understand fully.

Within the format, if data contains a comma, it is replaced with %!(VAGRANT_COMMA). This was preferred over an escape character such as \' because it is more friendly to tools like awk.

Newlines within the format are replaced with their respective standard escape sequence. Newlines become a literal \n within the output. Carriage returns become a literal \r.

Types

This section documents all the available types that may be outputted with the machine-readable output.

Type Description
box-name Name of a box installed into Vagrant.
box-provider Provider for an installed box.
cli-command A subcommand of vagrant that is available.
error-exit An error occurred that caused Vagrant to exit. This contains that error. Contains two data elements: type of error, error message.
provider-name The provider name of the target machine. targeted
state The state ID of the target machine. targeted
state-human-long Human-readable description of the state of the machine. This is the long version, and may be a paragraph or longer. targeted
state-human-short Human-readable description of the state of the machine. This is the short version, limited to at most a sentence. targeted