Add a Postfix-specific configuration testing resource (#4378)

Add a Postfix-specific configuration testing resource

docs/resources/postfix_conf.md.erb

@@ -0,0 +1,76 @@
+---
+title: About the postfix_conf Resource
+platform: os
+---
+
+# postfix_conf
+
+Use the `postfix_conf` Chef InSpec audit resource to test the main configuration of the Postfix Mail Transfer Agent.
+
+<br>
+
+## Availability
+
+### Installation
+
+This resource is distributed along with Chef InSpec itself. You can use it automatically.
+
+### Version
+
+## Syntax
+
+A `postfix_conf` resource block declares the configuration settings to be tested:
+
+	describe postfix_conf do
+	  its('setting_name') { should cmp 'value' }
+	end
+
+where
+
+* `'setting_name'` is a setting key defined in main.cf
+* `{ should cmp 'value' }` is the value to be expected
+
+When using `postfix_conf` with a custom configuration directory, the following syntax can be used:
+
+	describe postfix_conf('path') do
+	  ...
+	end
+
+where
+
+* `'path'` is the path to your Postfix configuration (ex. '/etc/my/postfix/path/main.cf')
+
+<br>
+
+## Properties
+
+This resource supports any of the settings listed in the main.cf file as properties.
+
+<br>
+
+## Examples
+
+The following examples show how to use this Chef InSpec audit resource.
+
+### Test basic Postfix configuration settings in the main.cf file
+
+For example, the following Postfix configuration:
+
+	/etc/postfix/main.cf:
+		myorigin = $myhostname
+		myhostname = host.local.domain
+		mynetworks = 127.0.0.0/8
+
+can be tested like this:
+
+	describe postfix_conf do
+	  its('myorigin') { should cmp '$myhostname' }
+	  its('myhostname') { should cmp 'host.local.domain' }
+	  its('mynetworks') { should cmp '127.0.0.0/8' }
+	end
+
+<br>
+
+## Matchers
+
+For a full list of available matchers, please visit our [matchers page](https://www.inspec.io/docs/reference/matchers/).

lib/inspec/resources.rb

@@ -84,6 +84,7 @@ require "inspec/resources/passwd"
 require "inspec/resources/pip"
 require "inspec/resources/platform"
 require "inspec/resources/port"
+require "inspec/resources/postfix_conf"
 require "inspec/resources/postgres"
 require "inspec/resources/postgres_conf"
 require "inspec/resources/postgres_hba_conf"

lib/inspec/resources/postfix_conf.rb

@@ -0,0 +1,31 @@
+require "inspec/resources/ini"
+require "inspec/utils/simpleconfig"
+
+module Inspec::Resources
+  class PostfixConf < IniConfig
+    name "postfix_conf"
+    supports platform: "linux"
+    desc "Use the postfix_conf Inspec audit resource to test the configuration of the Postfix Mail Transfer Agent"
+
+    # Allow user to specify a custom configuration path, use default Postfix configuration path if no custom path is provided
+    def initialize(*opts)
+      @params = {}
+      if opts.length == 1
+        @raw_content = load_raw_content(opts)
+      else
+        @raw_content = load_raw_content("/etc/postfix/main.cf")
+      end
+      @params = parse(@raw_content)
+    end
+
+    def parse(content)
+      SimpleConfig.new(content).params
+    end
+
+    private
+
+    def resource_base_name
+      "POSTFIX_CONF"
+    end
+  end
+end

test/helpers/mock_loader.rb

@@ -159,6 +159,7 @@ class MockLoader
       "/fakepath/fakefile" => emptyfile.call,
       "C:/fakepath/fakefile" => emptyfile.call,
       "/etc/cron.d/crondotd" => mockfile.call("crondotd"),
+      "/etc/postfix/main.cf" => mockfile.call("main.cf"),
     }
 
     # create all mock commands

test/unit/mock/files/main.cf

@@ -0,0 +1,4 @@
+# Test main configuration for Postfix
+
+test_parameter = value
+other_test_param = $value

test/unit/resources/postfix_conf_test.rb

@@ -0,0 +1,13 @@
+require "helper"
+require "inspec/resource"
+require "inspec/resources/postfix_conf"
+
+describe "Inspec::Resources::Postfix_Conf" do
+
+  it "Test default parsing of main.cf on Centos 7" do
+    resource = MockLoader.new(:centos7).load_resource("postfix_conf")
+    result = { "test_parameter" => "value", "other_test_param" => "$value" }
+    _(resource.params).must_equal result
+    _(resource.value(%w{test_parameter})).must_equal "value"
+  end
+end