Add linter for passing pkgs as list

This patch adds a new linter that ensures packages are being
passed as a list rather than using with_items. It also adds a
test for the new linter and adds the test to the existing linter
CI job script.

Change-Id: Iffd7284fb1c7cc41df2a4e271821e51bb274c3a3

ansible-lint/PassListToPackageModules.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python
+# Copyright 2017, Rackspace US, Inc.
+#
+# 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.
+"""Ansible linter for passing packages as list to package modules."""
+import os
+import unittest
+
+from ansiblelint import AnsibleLintRule, RulesCollection, Runner
+
+TEST_PLAYBOOK_DIR = "{}/test/".format(
+    os.path.dirname(os.path.realpath(__file__))
+)
+PACKAGE_MODULES = [
+    'apt',
+    'dnf',
+    'package',
+    'pip',
+    'yum',
+    'zypper'
+]
+
+
+def is_package_action(task):
+    """Test if task is using a package module."""
+    return task['action']['__ansible_module__'] in PACKAGE_MODULES
+
+
+class PassListToPackageModules(AnsibleLintRule):
+    """Ansible linter for passing packages as list to package modules."""
+    id = 'OSA0002'
+    shortdesc = 'Pass packages as a list to package modules'
+    description = (
+        "When passing multiple packages to a package module, pass the "
+        "packages as a list rather than using 'with_items'. This provides a "
+        "performance boost for deployments."
+    )
+    tags = ['performance']
+
+    def matchtask(self, file, task):
+        """Search the task for our concerns."""
+        return is_package_action(task) and 'with_items' in task
+
+
+class TestPassListToPackageModules(unittest.TestCase):
+    """Test the PassListToPackageModules lint rule."""
+    collection = RulesCollection()
+
+    def setUp(self):
+        """Set up the linter testing."""
+        self.collection.register(PassListToPackageModules())
+
+    def test_file_positive(self):
+        """A valid playbook should pass the linter."""
+        playbook = '{}/package_module_pass_list.yml'.format(
+            TEST_PLAYBOOK_DIR
+        )
+        runner = Runner(self.collection, playbook, [], [], [])
+        self.assertEqual([], runner.run())
+
+    def test_file_negative(self):
+        """An invalid playbook should fail the linter."""
+        playbook = '{}/package_module_with_items.yml'.format(
+            TEST_PLAYBOOK_DIR
+        )
+        runner = Runner(self.collection, playbook, [], [], [])
+        self.assertNotEqual([], runner.run())
+
+
+if __name__ == '__main__':
+    unittest.main()

ansible-lint/test/package_module_pass_list.yml

@@ -0,0 +1,27 @@
+# Copyright 2017, Rackspace US, Inc.
+#
+# 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.
+---
+
+- hosts: all
+  vars:
+    packages_to_install:
+      - bash
+      - tmux
+      - vim
+  tasks:
+
+    - name: Install packages using a list
+      package:
+        name: "{{ packages_to_install }}"
+        state: present

ansible-lint/test/package_module_with_items.yml

@@ -0,0 +1,28 @@
+# Copyright 2017, Rackspace US, Inc.
+#
+# 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.
+---
+
+- hosts: all
+  vars:
+    packages_to_install:
+      - bash
+      - tmux
+      - vim
+  tasks:
+
+    - name: Install packages using with_items
+      package:
+        name: "{{ item }}"
+        state: present
+      with_items: "{{ packages_to_install }}"

test-ansible-lint.sh

@@ -36,5 +36,8 @@ export COMMON_TESTS_PATH="${WORKING_DIR}/tests/common"
 # Ensure that the Ansible environment is properly prepared
 source "${COMMON_TESTS_PATH}/test-ansible-env-prep.sh"
 
+# Run linter tests
+python -m unittest discover -s ${WORKING_DIR}/ansible-lint/ -p "*.py"
+
 # Execute ansible-lint
 ansible-lint ${WORKING_DIR} -R -r ${WORKING_DIR}/ansible-lint/