Test Cookbook

Description

Interprets and rewrites node attributes defined in roles to provide more dynamicity. For instance, it can be used to get the value of the fqdn in a role by setting an attribute to "node['fqdn']". This cookbook will replace "node['fqdn']" by its true value at execution (in compile phase) so it is available to other cookbooks. This allows a role to be more shareable between nodes.

Different methods of substitution are available. Each method has its own recipe but all are included by default recipe.

Known limitation: derived attributes defined in attribute files will not read the rewritten values. This is because attribute files are initialized before recipes are compiled, so before the substitutions take place. This will probably not be fixed as it is actually a feature to do the substitution during the cookbook compilation phase, so you may use as source an attribute defined in some other cookbook. Moreover, this limitation should not be encountered very often and can be easily overcome by redefining the derived attributes.

Requirements

Cookbooks and gems

Declared in metadata.rb and in Gemfile.

Platforms

It should work on any platform as it is pure ruby. However it is just tested with kitchen on a Centos 7 docker image.

Usage

To be started

Add the default recipe in you runlist in any position you want, knowing that a source must be before and a reader must be after to see the effect in compile phase.

You may also want to tweak attributes (like whitelisting).

Read recipes documentation for more details.

Test

This cookbook is tested with kitchen on a Centos 7 docker image. A test cookbook is used to extract attributes after default recipe has run.

For more information, see .kitchen.yml and test directory.

Attributes

Configuration is done by overriding default attributes. All configuration keys have a default defined in attributes/default.rb. Please read it to have a comprehensive view of what and how you can configure this cookbook behavior.

Recipes

default

Include replace and then eval recipes. So it performs all substitutions, one after another. Attribute key (keys in hashmaps) are also modified if needed.

Note that by default, eval has no effect as no attribute is whitelisted. In contrary, replace is executed on all attributes.

You can look at examples defined as tests for more information.

eval

Evaluate (with the use of eval method) whitelisted (default: none) attributes as if there were referenced in a double-quote string and set the result as new attribute value. For instance, an attribute with value "1+#{1+1}" will be rewrited as "1+2" (as it would be in ruby).

Be careful with this substitution method as you can execute any ruby code. Be sure to whitelist only the attributes you need.

You can look at examples defined as tests for more information.

replace

Replace (recursively) whitelisted (default: all) attributes of the form "node['foo']['bar']" to their "true" value. It is not a string interpolation nor a substring replacement: it will work solely if the attributes value is exactly "node['something']".

If the target value does not exist (like "node['doesnotexist']"), it keeps the current value (that is the string "node['doesnotexist']").

You can look at examples defined as tests for more information.

Libraries

Provide implementation of the different methods: eval and replace.

Resources/Providers

None.

Changelog

Available in CHANGELOG.

Contributing

Please read carefully CONTRIBUTING.md before making a merge request.

License and Author

• Author:: Samuel Bernard (samuel.bernard@s4m.io)

Copyright:: 2016, Sam4Mobile

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.