Add a validation that checks for available update

This patch adds a validation that checks for newer versions of
python-tripleoclient. The check is done through the
check_package_update module which uses yum list to find available
versions of a package.

Change-Id: I19660980618fae318555401f5a7be01cb4d0ef2b

releasenotes/notes/check-latest-minor-version-14befc616a59002b.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    New validation to check for latest minor version of python-tripleoclient
+  - |
+    New module to check for new minor and major versions of a package

tripleo_validations/tests/library/test_check_package_update.py

@@ -0,0 +1,103 @@
+# -*- coding: utf-8 -*-
+
+# 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.
+
+from mock import MagicMock
+from mock import patch
+
+from tripleo_validations.tests import base
+from validations.library.check_package_update import check_update
+from validations.library.check_package_update import get_package_details
+
+
+PKG_INSTALLED = """\
+Last metadata expiration check: 1 day, 3:05:37 ago on Mon Jun  5 11:55:16 2017.
+Installed Packages
+foo-package.x86_64          2:6.1.5-1          @spideroak-one-stable
+"""
+
+# This stretches the boundaries of a realistic yum list output a bit
+# but it's more explicit for testing.
+PKG_AVAILABLE = """\
+Last metadata expiration check: 1 day, 3:06:30 ago on Mon Jun  5 11:55:16 2017.
+Available Packages
+foo-package.i386              2:9.1.0-1          foo-stable
+foo-package.i386              2:6.2.3-1          foo-stable
+foo-package.x86_64            2:8.0.0-1          foo-stable
+foo-package.x86_64            2:7.0.0-1          foo-stable
+foo-package.x86_64            2:6.2.0-1          foo-stable
+foo-package.x86_64            2:6.1.6-1          foo-stable
+"""
+
+
+class TestGetPackageDetails(base.TestCase):
+    def setUp(self):
+        super(TestGetPackageDetails, self).setUp()
+        self.entry = get_package_details("""\
+foo-package.x86_64            2:6.2.0-1          spideroak-one-stable
+""")
+
+    def test_name(self):
+        self.assertEqual(self.entry.name, 'foo-package')
+
+    def test_arch(self):
+        self.assertEqual(self.entry.arch, 'x86_64')
+
+    def test_version(self):
+        self.assertEqual(self.entry.version, '6.2.0')
+
+
+class TestCheckUpdate(base.TestCase):
+    def setUp(self):
+        super(TestCheckUpdate, self).setUp()
+        self.module = MagicMock()
+
+    def test_unsupported_pkg_mgr_fails(self):
+        check_update(self.module, 'foo-package', 'apt')
+        self.module.fail_json.assert_called_with(
+            msg='Package manager "apt" is not supported.')
+
+    @patch('validations.library.check_package_update._command')
+    def test_fails_if_installed_package_not_found(self, mock_command):
+        mock_command.side_effect = [
+            ['', 'No package found.'],
+        ]
+        check_update(self.module, 'foo-package', 'yum')
+        self.module.fail_json.assert_called_with(
+            msg='No package found.')
+
+    @patch('validations.library.check_package_update._command')
+    def test_returns_current_and_available_versions(self, mock_command):
+        mock_command.side_effect = [
+            [PKG_INSTALLED, ''],
+            [PKG_AVAILABLE, ''],
+        ]
+        check_update(self.module, 'foo-package', 'yum')
+        self.module.exit_json.assert_called_with(changed=False,
+                                                 name='foo-package',
+                                                 current_version='6.1.5',
+                                                 latest_minor_version='6.2.0',
+                                                 latest_major_version='8.0.0')
+
+    @patch('validations.library.check_package_update._command')
+    def test_returns_current_version_if_no_updates(self, mock_command):
+        mock_command.side_effect = [
+            [PKG_INSTALLED, ''],
+            ['', 'No packages found'],
+        ]
+        check_update(self.module, 'foo-package', 'yum')
+        self.module.exit_json.assert_called_with(changed=False,
+                                                 name='foo-package',
+                                                 current_version='6.1.5',
+                                                 latest_minor_version='6.1.5',
+                                                 latest_major_version=None)

validations/check-latest-minor-version.yaml

@@ -0,0 +1,23 @@
+---
+- hosts: undercloud
+  vars:
+    metadata:
+      name: Check if latest minor version is installed
+      description: >
+        Makes sure python-tripleoclient is at its latest minor version
+        before starting an upgrade.
+      groups:
+        - pre-upgrade
+    packages:
+      - python-tripleoclient
+  tasks:
+  - name: Get available updates for packages
+    check_package_update: package={{ item }} pkg_mgr={{ ansible_pkg_mgr }}
+    with_items: "{{ packages }}"
+    register: updates
+
+  - name: Check if current version is latest minor
+    with_items: "{{ updates.results }}"
+    assert:
+      that: "item.latest_minor_version == item.current_version"
+      msg: "A newer version of the {{ item.name }} package is available: {{ item.latest_minor_version }} (currently {{ item.current_version }})."

validations/library/check_package_update.py

@@ -0,0 +1,150 @@
+#!/usr/bin/env python
+# Copyright 2017 Red Hat, Inc.
+# All Rights Reserved.
+#
+# 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.
+
+""" Check for available updates for a given package."""
+
+import collections
+import subprocess
+
+from ansible.module_utils.basic import AnsibleModule
+
+DOCUMENTATION = '''
+---
+module: check_package_update
+short_description: Check for available updates for a given package
+options:
+    package:
+        required: true
+        description:
+            - The name of the package you want to check
+        type: str
+    pkg_mgr:
+        required: true
+        description:
+            - Supported Package Manager, DNF or YUM
+        type: str
+author: "Florian Fuchs"
+'''
+
+EXAMPLES = '''
+- hosts: webservers
+  tasks:
+    - name: Get available updates for packages
+      check_package_update:
+        package: python-tripleoclient
+        pkg_mgr: {{ ansible_pkg_mgr}}
+'''
+
+SUPPORTED_PKG_MGRS = (
+    'yum',
+    'dnf',
+)
+
+
+PackageDetails = collections.namedtuple('PackageDetails',
+                                        ['name', 'arch', 'version'])
+
+
+def get_package_details(line):
+    # Parses an output line from a package manager's
+    # `list (available|installed)` command and returns
+    # a named tuple
+    parts = line.rstrip().split()
+    name, arch = parts[0].split('.')
+    # Version string, excluding release string and epoch
+    version = parts[1].split('-')[0].split(':')[-1]
+    return PackageDetails(name, arch, version)
+
+
+def _command(command):
+    # Return the result of a subprocess call
+    # as [stdout, stderr]
+    process = subprocess.Popen(command,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE,)
+    return process.communicate()
+
+
+def _get_installed_version_from_output(output, package):
+    for line in output.split('\n'):
+        if package in line:
+            return get_package_details(line)
+
+
+def _get_latest_available_versions(output, installed):
+    # Returns the latest available minor and major versions,
+    # one for each.
+    latest_minor = None
+    latest_major = None
+    # Get all packages with the same architecture
+    packages = list([get_package_details(line) for line in output.split('\n')
+                     if '{i.name}.{i.arch}'.format(i=installed) in line])
+    # Get all packages with the *same* major version
+    minor = sorted((p for p in packages
+                    if p.version[0] == installed.version[0]))
+    if len(minor) > 0:
+        latest_minor = minor[-1].version
+    # Get all packages with a *higher* available major version
+    major = sorted((p for p in packages
+                    if p.version[0] > installed.version[0]))
+    if len(major) > 0:
+        latest_major = major[-1].version
+    # If the output doesn't contain packages with the same major version
+    # let's assume the currently installed version as latest minor one.
+    if latest_minor is None:
+        latest_minor = installed.version
+    return latest_minor, latest_major
+
+
+def check_update(module, package, pkg_mgr):
+    if pkg_mgr not in SUPPORTED_PKG_MGRS:
+        module.fail_json(
+            msg='Package manager "{}" is not supported.'.format(pkg_mgr))
+        return
+
+    installed_stdout, installed_stderr = _command(
+        [pkg_mgr, 'list', 'installed', package])
+    # Fail the module if for some reason we can't lookup the current package.
+    if installed_stderr != '':
+        module.fail_json(msg=installed_stderr)
+        return
+    installed = _get_installed_version_from_output(installed_stdout, package)
+
+    available_stdout, available_stderr = _command(
+        [pkg_mgr, 'list', 'available', installed.name])
+    latest_minor_version, latest_major_version = \
+        _get_latest_available_versions(available_stdout, installed)
+
+    module.exit_json(changed=False,
+                     name=installed.name,
+                     current_version=installed.version,
+                     latest_minor_version=latest_minor_version,
+                     latest_major_version=latest_major_version)
+
+
+def main():
+    module = AnsibleModule(argument_spec=dict(
+        package=dict(required=True, type='str'),
+        pkg_mgr=dict(required=True, type='str')
+    ))
+
+    check_update(module,
+                 module.params.get('package'),
+                 module.params.get('pkg_mgr'))
+
+
+if __name__ == '__main__':
+    main()