inspec/docs/profiles.md
Adam Leff 97a9b3f42a Adding examples of using expect syntax (#2213)
As discussed during the Chef Community Summit 2017 in Seattle, many
more technical users wish to use `expect` syntax and wish to see
more examples of how to do so with InSpec resources.

Signed-off-by: Adam Leff <adam@leff.co>
2017-10-04 22:43:20 +02:00

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About InSpec Profiles

InSpec Profiles

InSpec supports the creation of complex test and compliance profiles, which organize controls to support dependency management and code reuse. Each profile is a standalone structure with its own distribution and execution flow.

Profile Structure

A profile should have the following structure::

examples/profile
├── README.md
├── controls
│   ├── example.rb
│   └── control_etc.rb
├── libraries
│   └── extension.rb
|── files
│   └── extras.conf
└── inspec.yml

where:

  • inspec.yml includes the profile description (required)
  • controls is the directory in which all tests are located (required)
  • libraries is the directory in which all InSpec resource extensions are located (optional)
  • files is the directory with additional files that a profile can access (optional)
  • README.md should be used to explain the profile, its scope, and usage

See a complete example profile in the InSpec open source repository: https://github.com/chef/inspec/tree/master/examples/profile

inspec.yml

Each profile must have an inspec.yml file that defines the following information:

  • Use name to specify a unique name for the profile. Required.
  • Use title to specify a human-readable name for the profile.
  • Use maintainer to specify the profile maintainer.
  • Use copyright to specify the copyright holder.
  • Use copyright_email to specify support contact information for the profile, typically an email address.
  • Use license to specify the license for the profile.
  • Use summary to specify a one line summary for the profile.
  • Use description to specify a multiple line description of the profile.
  • Use version to specify the profile version.
  • Use supports to specify a list of supported platform targets.
  • Use depends to define a list of profiles on which this profile depends.

name is required; all other profile settings are optional. For example:

name: ssh
title: Basic SSH
maintainer: Chef Software, Inc.
copyright: Chef Software, Inc.
copyright_email: support@chef.io
license: Proprietary, All rights reserved
summary: Verify that SSH Server and SSH Client are configured securely
version: 1.0.0
supports:
  - os-family: linux
depends:
  - name: profile
    path: ../path/to/profile

Verify Profiles

Use the inspec check command to verify the implementation of a profile:

$ inspec check examples/profile

Platform Support

Use the supports setting in the inspec.yml file to specify one (or more) platforms for which a profile is targeting. The list of supported platforms may contain simple names, names and versions, or detailed flags, and may be combined arbitrarily. For example, to target anything running Debian Linux:

name: ssh
supports:
  - os-name: debian

and to target only Ubuntu version 14.04

name: ssh
supports:
  - os-name: ubuntu
    release: 14.04

and to target the entire RedHat platform (including CentOS and Oracle Linux):

name: ssh
supports:
  - os-family: redhat

and to target anything running on Amazon AWS:

name: ssh
supports:
  - platform: aws

and to target all of these examples in a single inspec.yml file:

name: ssh
supports:
  - os-name: debian
  - os-name: ubuntu
    release: 14.04
  - os-family: redhat
  - platform: aws

Profile Dependencies

An InSpec profile can bring in the controls and custom resources from another InSpec profile. Additionally, when inheriting the controls of another profile, a profile can skip or even modify those included controls.

Defining the Dependencies

Before a profile can use controls from another profile, the to-be-included profile needs to be specified in the including profiles inspec.yml file in the depends section. For each profile to be included, a location for the profile from where to be fetched and a name for the profile should be included. For example:

depends:
- name: linux-baseline
  url: https://github.com/dev-sec/linux-baseline/archive/master.tar.gz
- name: ssh-baseline
  url: https://github.com/dev-sec/ssh-baseline/archive/master.tar.gz

InSpec supports a number of dependency sources.

path

The path setting defines a profile that is located on disk. This setting is typically used during development of profiles and when debugging profiles.

depends:
- name: my-profile
  path: /absolute/path
- name: another
  path: ../relative/path

url

The url setting specifies a profile that is located at an HTTP- or HTTPS-based URL. The profile must be accessible via a HTTP GET operation and must be a valid profile archive (zip, tar, or tar.gz format).

depends:
- name: my-profile
  url: https://my.domain/path/to/profile.tgz
- name: profile-via-git
  url: https://github.com/myusername/myprofile-repo/archive/master.tar.gz

git

A git setting specifies a profile that is located in a git repository, with optional settings for branch, tag, commit, and version. The source location is translated into a URL upon resolution. This type of dependency supports version constraints via semantic versioning as git tags.

For example:

depends:
- name: git-profile
  git: http://url/to/repo
  branch:  desired_branch
  tag:     desired_version
  commit:  pinned_commit
  version: semver_via_tags

supermarket

A supermarket setting specifies a profile that is located in a cookbook hosted on Chef Supermarket. The source location is translated into a URL upon resolution.

For example:

depends:
- name: supermarket-profile
  supermarket: supermarket-username/supermarket-profile

Available Supermarket profiles can be listed with inspec supermarket profiles.

compliance

A compliance setting specifies a profile that is located on the Chef Automate or Chef Compliance server.

For example:

depends:
  - name: linux
    compliance: base/linux

Vendoring Dependencies

When you execute a local profile, the inspec.yml file will be read in order to source any profile dependencies. It will then cache the dependencies locally and generate an inspec.lock file.

If you add or update dependencies in inspec.yml, dependencies may be re-vendored and the lockfile updated with inspec vendor --overwrite

Using Controls from an Included Profile

Once defined in the inspec.yml, controls from the included profiles can be used! Lets look at some examples.

Including All Controls from a Profile

With the include_controls command in a profile, all controls from the named profile will be executed every time the including profile is executed.

Include Controls

In the example above, every time my-app-profile is executed, all the controls from my-baseline are also executed. Therefore, the following controls would be executed:

  • myapp-1
  • myapp-2
  • myapp-3
  • baseline-1
  • baseline-2

This is a great reminder that having a good naming convention for your controls is helpful to avoid confusion when including controls from other profiles!

Skipping a Control from a Profile

What if one of the controls from the included profile does not apply to your environment? Luckily, it is not necessary to maintain a slightly-modified copy of the included profile just to delete a control. The skip_control command tells InSpec to not run a particular control.

Include Controls with Skip

In the above example, all controls from my-app-profile and my-baseline profile will be executed every time my-app-profile is executed except for control baseline-2 from the my-baseline profile.

Modifying a Control

Let's say a particular control from an included profile should still be run, but the impact isn't appropriate? Perhaps the test should still run, but if it fails, it should be treated as low severity instead of high severity?

When a control is included, it can also be modified!

Include Controls with Modification

In the above example, all controls from my-baseline are executed along with all the controls from the including profile, my-app-profile. However, should control baseline-1 fail, it will be raised with an impact of 0.5 instead of the originally-intended impact of 1.0.

Selectively Including Controls from a Profile

If there are only a handful of controls that should be executed from an included profile, it's not necessarily to skip all the unneeded controls, or worse, copy/paste those controls bit-for-bit into your profile. Instead, use the require_controls command.

Require Controls

Whenever my-app-profile is executed, in addition to its own controls, it will run only the controls specified in the require_controls block. In the case, the following controls would be executed:

  • myapp-1
  • myapp-2
  • myapp-3
  • baseline-2
  • baseline-4

Controls baseline-1, baseline-3, and baseline-5 would not be run, just as if they were manually skipped. This method of including specific controls ensures only the controls specified are executed; if new controls are added to a later version of my-baseline, they would not be run.

And, just the way its possible to modify controls when using include_controls, controls can be modified as well.

Require Controls with Modification

As with the prior example, only baseline-2 and baseline-4 are executed, but if baseline-2 fails, it will report with an impact of 0.5 instead of the originally-intended 1.0 impact.

Using Resources from an Included Profile

By default, all of the custom resources from a listed dependency are available for use in your profile. If two of your dependencies provide a resource with the same name, you can use the require_resource DSL function to disambiguate the two:

require_resource(profile: 'my_dep', resource: 'my_res',
                 as: 'my_res2')

This will allow you to reference the resource my_res from the profile my_dep using the name my_res2.

Profile Attributes

Attributes may be used in profiles to define secrets, such as user names and passwords, that should not otherwise be stored in plain-text in a cookbook. First specify a variable in the control for each secret, then add the secret to a Yaml file located on the local machine, and then run inspec exec and specify the path to that Yaml file using the --attrs attribute.

For example, a control:

# define these attributes on the top-level of your file and re-use them across all tests!
val_user = attribute('user', default: 'alice', description: 'An identification for the user')
val_password = attribute('password', description: 'A value for the password')

control 'system-users' do
  impact 0.8
  desc '
    This test assures that the user "Bob" has a user installed on the system, along with a
    specified password.
  '

  describe val_user do
    it { should eq 'bob' }
  end

  describe val_password do
    it { should eq 'secret' }
  end
end

And a Yaml file named profile-attribute.yml:

user: bob
password: secret

The following command runs the tests and applies the secrets specified in profile-attribute.yml:

$ inspec exec examples/profile-attribute --attrs examples/profile-attribute.yml

See the full example in the InSpec open source repository: https://github.com/chef/inspec/tree/master/examples/profile-attribute

Profile files

An InSpec profile may contain additional files that can be accessed during tests. This covers use-cases where e.g. a list of ports is provided to be tested.

To access these files, they must be stored in the files directory at the root of a profile. They are accessed by their name relative to this folder with inspec.profile.file(...).

Here is an example for reading and testing a list of ports. The folder structure is:

examples/profile
├── controls
│   ├── example.rb
|── files
│   └── services.yml
└── inspec.yml

With services.yml containing:

- service_name: httpd-alpha
  port: 80
- service_name: httpd-beta
  port: 8080

The tests in example.rb can now access this file:

my_services = yaml(content: inspec.profile.file('services.yml')).params

my_services.each do |s|
  describe service(s['name']) do
    it { should be_running }
  end

  describe port(s['port']) do
    it { should be_listening }
  end
end

"should" vs. "expect" syntax

Users familiar with the RSpec testing framework may know that there are two ways to write test statements: should and expect. The RSpec community decided that expect is the preferred syntax. However, InSpec recommends the should syntax as it tends to read more easily to those users who are not as technical.

InSpec will continue to support both methods of writing tests. Consider this file test:

describe file('/tmp/test.txt') do
  it { should be_file }
end

This can be re-written with expect syntax

describe file('/tmp/test.txt') do
  it 'should be a file' do
    expect(subject).to(be_file)
  end
end

The output of both of the above examples looks like this:

File /tmp/test.txt
   ✔  should be a file

In addition, you can make use of the subject keyword to further control your output if you choose:

describe 'test file' do
  subject { file('/tmp/test.txt') }
  it 'should be a file' do
    expect(subject).to(be_file)
  end
end

... which will render the following output:

test file
  ✔  should be a file