Add rpm_dbpath support to the package resource (#1960)

Signed-off-by: Jerry Aldrich III <jerry@chef.io>

docs/resources/package.md.erb

@@ -96,6 +96,12 @@ The following examples show how to use this InSpec audit resource.
       it { should_not be_running }
     end
 
+### Verify if some_package is installed according to my_rpmdb
+
+   describe package('some_package', rpm_dbpath: '/var/lib/my_rpmdb') do
+     it { should be_installed }
+   end
+
 ### Verify if Memcached is installed, enabled, and running
 
 Memcached is an in-memory key-value store that helps improve the performance of database-driven websites and can be installed, maintained, and tested using the `memcached` cookbook (maintained by Chef). The following example is from the `memcached` cookbook and shows how to use a combination of the `package`, `service`, and `port` InSpec audit resources to test if Memcached is installed, enabled, and running:

lib/resources/package.rb

@@ -19,7 +19,7 @@ module Inspec::Resources
       end
     "
 
-    def initialize(package_name = nil) # rubocop:disable Metrics/AbcSize
+    def initialize(package_name = nil, opts = {}) # rubocop:disable Metrics/AbcSize
       @package_name = package_name
       @name = @package_name
       @cache = nil
@@ -30,7 +30,7 @@ module Inspec::Resources
       if os.debian?
         @pkgman = Deb.new(inspec)
       elsif os.redhat? || %w{suse amazon fedora}.include?(os[:family])
-        @pkgman = Rpm.new(inspec)
+        @pkgman = Rpm.new(inspec, opts)
       elsif ['arch'].include?(os[:family])
         @pkgman = Pacman.new(inspec)
       elsif ['darwin'].include?(os[:family])
@@ -46,6 +46,8 @@ module Inspec::Resources
       else
         return skip_resource 'The `package` resource is not supported on your OS yet.'
       end
+
+      evaluate_missing_requirements
     end
 
     # returns true if the package is installed
@@ -71,6 +73,14 @@ module Inspec::Resources
     def to_s
       "System Package #{@package_name}"
     end
+
+    private
+
+    def evaluate_missing_requirements
+      missing_requirements_string = @pkgman.missing_requirements.uniq.join(', ')
+      return if missing_requirements_string.empty?
+      skip_resource "The following requirements are not met for this resource: #{missing_requirements_string}"
+    end
   end
 
   class PkgManagement
@@ -78,6 +88,12 @@ module Inspec::Resources
     def initialize(inspec)
       @inspec = inspec
     end
+
+    def missing_requirements
+      # Each provider can provide an Array of missing requirements that will be
+      # combined into a `skip_resource` message
+      []
+    end
   end
 
   # Debian / Ubuntu
@@ -104,8 +120,25 @@ module Inspec::Resources
 
   # RHEL family
   class Rpm < PkgManagement
+    def initialize(inspec, opts)
+      super(inspec)
+
+      @dbpath = opts.fetch(:rpm_dbpath, nil)
+    end
+
+    def missing_requirements
+      missing_requirements = []
+
+      unless @dbpath.nil? || inspec.directory(@dbpath).directory?
+        missing_requirements << "RPMDB #{@dbpath} does not exist"
+      end
+
+      missing_requirements
+    end
+
     def info(package_name)
-      cmd = inspec.command("rpm -qia #{package_name}")
+      rpm_cmd = rpm_command(package_name)
+      cmd = inspec.command(rpm_cmd)
       # CentOS does not return an error code if the package is not installed,
       # therefore we need to check for emptyness
       return nil if cmd.exit_status.to_i != 0 || cmd.stdout.chomp.empty?
@@ -133,6 +166,17 @@ module Inspec::Resources
         type: 'rpm',
       }
     end
+
+    private
+
+    def rpm_command(package_name)
+      cmd = ''
+      cmd += 'rpm -qia'
+      cmd += " --dbpath #{@dbpath}" if @dbpath
+      cmd += ' ' + package_name
+
+      cmd
+    end
   end
 
   # MacOS / Darwin implementation

test/helper.rb

@@ -153,6 +153,8 @@ class MockLoader
       # Test DH parameters, 2048 bit long safe prime, generator 2 for dh_params in PEM format
       'dh_params.dh_pem' => mockfile.call('dh_params.dh_pem'),
       'default.toml' => mockfile.call('default.toml'),
+      '/var/lib/fake_rpmdb' => mockdir.call(true),
+      '/var/lib/rpmdb_does_not_exist' => mockdir.call(false),
     }
 
     # create all mock commands
@@ -165,6 +167,8 @@ class MockLoader
       mock.mock_command('', '', '', 0)
     }
 
+    cmd_exit_1 = mock.mock_command('', '', '', 1)
+
     mock.commands = {
       'ps axo pid,pcpu,pmem,vsz,rss,tty,stat,start,time,user,command' => cmd.call('ps-axo'),
       'ps axo label,pid,pcpu,pmem,vsz,rss,tty,stat,start,time,user:32,command' => cmd.call('ps-axoZ'),
@@ -181,6 +185,8 @@ class MockLoader
       'yum -v repolist all'  => cmd.call('yum-repolist-all'),
       'dpkg -s curl' => cmd.call('dpkg-s-curl'),
       'rpm -qia curl' => cmd.call('rpm-qia-curl'),
+      'rpm -qia --dbpath /var/lib/fake_rpmdb curl' => cmd.call('rpm-qia-curl'),
+      'rpm -qia --dbpath /var/lib/rpmdb_does_not_exist curl' => cmd_exit_1,
       'pacman -Qi curl' => cmd.call('pacman-qi-curl'),
       'brew info --json=v1 curl' => cmd.call('brew-info--json-v1-curl'),
       'gem list --local -a -q ^not-installed$' => cmd.call('gem-list-local-a-q-not-installed'),

test/unit/resources/package_test.rb

@@ -34,14 +34,44 @@ describe 'Inspec::Resources::Package' do
   end
 
   # centos
-  it 'verify centos package parsing' do
+  describe 'Rpm' do # rubocop:disable BlockLength
+    let(:pkg) do
+      {
+        name: 'curl',
+        installed: true,
+        version: '7.29.0-19.el7',
+        type: 'rpm',
+      }
+    end
+
+    it 'can parse RPM package info' do
       resource = MockLoader.new(:centos7).load_resource('package', 'curl')
-    pkg = { name: 'curl', installed: true, version: '7.29.0-19.el7', type: 'rpm' }
       _(resource.installed?).must_equal true
       _(resource.version).must_equal '7.29.0-19.el7'
       _(resource.info).must_equal pkg
     end
 
+    it 'can build an `rpm` command containing `--dbpath`' do
+      resource = MockLoader.new(:centos7).load_resource(
+        'package',
+        'curl',
+        rpm_dbpath: '/var/lib/fake_rpmdb',
+      )
+      _(resource.installed?).must_equal true
+      _(resource.version).must_equal '7.29.0-19.el7'
+      _(resource.info).must_equal pkg
+    end
+
+    it 'can add to `resource_skipped` when `--rpmdb` path does not exist' do
+      resource = MockLoader.new(:centos7).load_resource(
+        'package',
+        'curl',
+        rpm_dbpath: '/var/lib/rpmdb_does_not_exist',
+      )
+      _(resource.resource_skipped).wont_equal nil
+    end
+  end
+
   # hpux
   it 'verify hpux package parsing' do
     resource = MockLoader.new(:hpux).load_resource('package', 'vim')