Merge lp:~james-page/charm-helpers/get-upstream-version into lp:charm-helpers

[James Page]

Add a helper to grab the upstream version of an installed package.

[lp:~james-page/charm-helpers/get-upstream-version]

632. By James Page on 2016-09-21

Refactor openstack.utils to use get_upstream_version

[Liam Young (gnuoy)]

LGTM

review: Approve

=== modified file 'charmhelpers/contrib/openstack/utils.py'
--- charmhelpers/contrib/openstack/utils.py	2016-09-16 09:27:02 +0000
+++ charmhelpers/contrib/openstack/utils.py	2016-09-21 07:37:06 +0000
@@ -81,7 +81,12 @@
     service_resume,
     restart_on_change_helper,
 )
-from charmhelpers.fetch import apt_install, apt_cache, install_remote
+from charmhelpers.fetch import (
+    apt_install,
+    apt_cache,
+    install_remote,
+    get_upstream_version
+)
 from charmhelpers.contrib.storage.linux.utils import is_block_device, zap_disk
 from charmhelpers.contrib.storage.linux.loopback import ensure_loopback_device
 from charmhelpers.contrib.openstack.exceptions import OSContextError
@@ -1894,25 +1899,10 @@
 
 def os_application_version_set(package):
     '''Set version of application for Juju 2.0 and later'''
-    import apt_pkg as apt
-    cache = apt_cache()
-    application_version = None
-    application_codename = os_release(package)
-
-    try:
-        pkg = cache[package]
-        if not pkg.current_ver:
-            juju_log('Package {} is not currently installed.'.format(package),
-                     DEBUG)
-        else:
-            application_version = apt.upstream_version(pkg.current_ver.ver_str)
-    except:
-        juju_log('Package {} has no installation candidate.'.format(package),
-                 DEBUG)
-
+    application_version = get_upstream_version(package)
     # NOTE(jamespage) if not able to figure out package version, fallback to
     #                 openstack codename version detection.
     if not application_version:
-        application_version_set(application_codename)
+        application_version_set(os_release(package))
     else:
         application_version_set(application_version)
 
=== modified file 'charmhelpers/fetch/__init__.py'
--- charmhelpers/fetch/__init__.py	2016-08-11 15:47:44 +0000
+++ charmhelpers/fetch/__init__.py	2016-09-21 07:37:06 +0000
@@ -92,6 +92,7 @@
     apt_mark = fetch.apt_mark
     apt_hold = fetch.apt_hold
     apt_unhold = fetch.apt_unhold
+    get_upstream_version = fetch.get_upstream_version
 elif __platform__ == "centos":
     yum_search = fetch.yum_search
 
 
=== modified file 'charmhelpers/fetch/ubuntu.py'
--- charmhelpers/fetch/ubuntu.py	2016-09-16 13:27:28 +0000
+++ charmhelpers/fetch/ubuntu.py	2016-09-21 07:37:06 +0000
@@ -314,3 +314,23 @@
 
     else:
         subprocess.call(cmd, env=env)
+
+
+def get_upstream_version(package):
+    """Determine upstream version based on installed package
+
+    @returns None (if not installed) or the upstream version
+    """
+    import apt_pkg
+    cache = apt_cache()
+    try:
+        pkg = cache[package]
+    except:
+        # the package is unknown to the current apt cache.
+        return None
+
+    if not pkg.current_ver:
+        # package is known, but no version is currently installed.
+        return None
+
+    return apt_pkg.upstream_version(pkg.current_ver.ver_str)
 
=== modified file 'tests/fetch/test_fetch.py'
--- tests/fetch/test_fetch.py	2016-09-16 13:32:52 +0000
+++ tests/fetch/test_fetch.py	2016-09-21 07:37:06 +0000
@@ -40,7 +40,7 @@
             raise KeyError
         pkg.name = package
         if 'current_ver' in FAKE_APT_CACHE[package]:
-            pkg.current_ver = FAKE_APT_CACHE[package]['current_ver']
+            pkg.current_ver.ver_str = FAKE_APT_CACHE[package]['current_ver']
         else:
             pkg.current_ver = None
         return pkg
@@ -1269,3 +1269,13 @@
         from charmhelpers.fetch.centos import _run_yum_command
         _run_yum_command(["some", "command"], fatal=True)
         self.assertTrue(sleep.called)
+
+    @patch.object(osplatform, 'get_platform')
+    @patch('apt_pkg.Cache')
+    def test_get_upstream_version(self, cache, platform):
+        platform.return_value = 'ubuntu'
+        imp.reload(fetch)
+        cache.side_effect = fake_apt_cache
+        self.assertEqual(fetch.get_upstream_version('vim'), '7.3.547')
+        self.assertEqual(fetch.get_upstream_version('emacs'), None)
+        self.assertEqual(fetch.get_upstream_version('unknown'), None)