mirror of
https://github.com/inspec/inspec
synced 2024-11-24 05:33:17 +00:00
129 lines
3.9 KiB
Markdown
129 lines
3.9 KiB
Markdown
---
|
|
title: Resource DSL
|
|
---
|
|
|
|
# Resource DSL
|
|
|
|
Chef InSpec provides a mechanism for defining custom resources. These become
|
|
available with their respective names and provide easy functionality to
|
|
profiles.
|
|
|
|
## Resource location
|
|
|
|
Resources may be added to profiles in the libraries folder:
|
|
|
|
```bash
|
|
$ tree examples/profile
|
|
examples/profile
|
|
...
|
|
├── libraries
|
|
│ └── example_config.rb
|
|
```
|
|
|
|
## Resource structure
|
|
|
|
The smallest possible resource takes this form:
|
|
|
|
```ruby
|
|
class Tiny < Inspec.resource(1)
|
|
name 'tiny'
|
|
end
|
|
```
|
|
|
|
Resources are written as a regular Ruby class which inherits from
|
|
Inspec.resource. The number (1) specifies the version this resource
|
|
plugin targets. As Chef InSpec evolves, this interface may change and may
|
|
require a higher version.
|
|
|
|
The following attributes can be configured:
|
|
|
|
- name - Identifier of the resource (required)
|
|
- desc - Description of the resource (optional)
|
|
- example - Example usage of the resource (optional)
|
|
- supports - (Chef InSpec 2.0+) Platform restrictions of the resource (optional)
|
|
|
|
The following methods are available to the resource:
|
|
|
|
- inspec - Contains a registry of all other resources to interact with the operating system or target in general.
|
|
- skip\_resource - A resource may call this method to indicate that requirements aren't met. All tests that use this resource will be marked as skipped.
|
|
|
|
The following example shows a full resource using attributes and methods
|
|
to provide simple access to a configuration file:
|
|
|
|
```ruby
|
|
class ExampleConfig < Inspec.resource(1)
|
|
name 'example_config'
|
|
|
|
# Restrict to only run on the below platforms (if none were given, all OS's supported)
|
|
supports platform_family: 'fedora'
|
|
supports platform: 'centos', release: '6.9'
|
|
# Supports `*` for wildcard matcher in the release
|
|
supports platform: 'centos', release: '7.*'
|
|
|
|
desc '
|
|
Resource description ...
|
|
'
|
|
|
|
example '
|
|
describe example_config do
|
|
its("signal") { should eq "on" }
|
|
end
|
|
'
|
|
|
|
# Load the configuration file on initialization
|
|
def initialize(path = nil)
|
|
@path = path || '/etc/example.conf'
|
|
@params = SimpleConfig.new( read_content )
|
|
end
|
|
|
|
# Expose all parameters of the configuration file.
|
|
def method_missing(name)
|
|
@params[name]
|
|
end
|
|
|
|
private
|
|
|
|
def read_content
|
|
f = inspec.file(@path)
|
|
# Test if the path exist and that it's a file
|
|
if f.file?
|
|
# Retrieve the file's contents
|
|
f.content
|
|
else
|
|
# If the file doesn't exist, skip all tests that use example_config
|
|
raise Inspec::Exceptions::ResourceSkipped, "Can't read config at #{@path}"
|
|
end
|
|
end
|
|
end
|
|
```
|
|
|
|
For a full example, see our [example resource](https://github.com/chef/inspec/blob/master/examples/profile/libraries/example_config.rb).
|
|
|
|
## Lazy Loading
|
|
|
|
Prior to InSpec v4.16, resources were pre-loaded for every invocation
|
|
of `inspec`. This was a heavy and unnecessary burden on the system and
|
|
exacerbated startup times (especially on Windows).
|
|
|
|
As of InSpec v4.16, resources are lazily loaded into the `inspec`
|
|
process upon use. This greatly speeds up the initial startup costs of
|
|
the `inspec` process and only loads what you need to use. For example, `inspec
|
|
--version` no longer runs for 10 seconds!.
|
|
|
|
### Overriding Core Resources
|
|
|
|
Lazy loading does change the way the resource registry is handled in
|
|
ways that might break some assumptions. Specifically,
|
|
`inspec.<resource>` isn't pre-populated with the core resources that
|
|
InSpec ships with. If you make a local/custom resource of the same
|
|
name, referring to the core resource via `inspec.<resource>` will not
|
|
resolve to the core resource.
|
|
|
|
As such, overriding core resources is not recommended best practice.
|
|
|
|
If you really do need to do this, it is easiest to make a local
|
|
resource with a new name and refer to the core resource directly.
|
|
Otherwise, you need to ensure that the core resource you want is
|
|
registered (via `require "inspec/resource/<name>"`) _before_ your
|
|
profile is run to ensure it is eagerly loaded and in the global
|
|
resource registry.
|