# chef-validation

Perform validation on your node's attributes from a Cookbook's attribute metadata definitions.

## Supported Platforms

* Ubuntu 12.04 / 14.04
* CentOS

## Usage

Add the validation cookbook to your cookbook's metadata and define your attribute rules:

```
name             "my_app"
maintainer       "Jamie Winsor"
maintainer_email "jamie@vialstudios.com"
license          "MIT"
description      "Installs/Configures my_app"
long_description "Installs/Configures my_app"
version          "0.1.0"

depends "validation"

grouping "my_app",
  title: "My Application"
attribute "my_app/log_level",
  required: "required",
  default: "debug",
  choices: [
    "debug",
    "fatal",
    "warn",
    "info"
  ]
attribute "my_app/cookie",
  required: "required",
  default: "",
  type: "string"
```

Attribute rules are already part of Chef metadata. However, they are not used at all by the Chef client application itself. You'll need to ensure that you still initialize attributes to their supposedly default value in an attributes file or a recipe.

Since Chef client doesn't do anything with these attribute definitions we need to leverage the `validate_attributes` definition provided by this cookbook. Place a line like this in one of your cookbook's recipes.

```
validate_attributes "my_app"
```

I recommend placing this in the top of your "default" recipe for each cookbook that you maintain.

### Compile time validation

By default, attribute validation will occur at convergence time but this can be switched to compile time by setting an attribute on the `validate_attributes` definition.

```
validate_attributes "my_app" do
  mode :compile
end
```

### Convergence time validation

You can also explicitly validate at convergence

```
validate_attributes "my_app" do
  mode :converge
end
```

However, this is not necessary since `:converge` is the default mode.

### Filtering validation

The name parameter of the `validate_attributes` definition is also the `cookbook` parameter. Setting this to the name of a cookbook will cause attribute validations to only be run for the metadata of that cookbook for the resource the definition creates. You can have multiple `validate_attributes` definitions within your resource chain or you can validate against all of your run context's loaded cookbooks.

```
validate_attributes "all"
```

> Note: I swear to fucking god - if one of you makes a cookbook called "all" and puts that shit on the community site I will drink myself into the grave faster than I already am.

## License and Authors

Author:: Jamie Winsor (<jamie@vialstudios.com>)