rework package mirror selection

There are several changes here.
 * Datasource now has a 'availability_zone' getter.
 * get_package_mirror_info
   * Datasource convenience 'get_package_mirror_info' that calls
     the configured distro, and passes it the availability-zone
   * distro has a get_package_mirror_info method
   * get_package_mirror_info returns a dict that of name:mirror
     this is to facilitate use of 'security' and 'primary' archive.
   * this supports searching based on templates.  Any template
     that references undefined values is skipped.  These templates
     can contain 'availability_zone' (LP: #1037727)
   * distro's mirrors can be arch specific (LP: #1028501)
 * rename_apt_lists supports the "mirror_info" rather than single mirror
 * generate_sources_list supports mirror_info, and as a result, the
   ubuntu mirrors reference '$security' rather than security (LP: #1006963)
 * remove the DataSourceEc2 specific mirror selection, but instead
   rely on the above filtering, and the fact that 'ec2_region' is only
   defined if the availability_zone looks like a ec2 az.

3 files changed, 15 insertions, 38 deletions

diff --git a/cloudinit/sources/DataSourceCloudStack.py b/cloudinit/sources/DataSourceCloudStack.py
index 751bef4f..5c5f8bd7 100644
--- a/cloudinit/sources/DataSourceCloudStack.py
+++ b/cloudinit/sources/DataSourceCloudStack.py
@@ -132,7 +132,8 @@ class DataSourceCloudStack(sources.DataSource):
     def get_instance_id(self):
         return self.metadata['instance-id']
 
-    def get_availability_zone(self):
+    @property
+    def availability_zone(self):
         return self.metadata['availability-zone']
 
 
diff --git a/cloudinit/sources/DataSourceEc2.py b/cloudinit/sources/DataSourceEc2.py
index d9eb8f17..556dcafb 100644
--- a/cloudinit/sources/DataSourceEc2.py
+++ b/cloudinit/sources/DataSourceEc2.py
@@ -83,40 +83,6 @@ class DataSourceEc2(sources.DataSource):
     def get_availability_zone(self):
         return self.metadata['placement']['availability-zone']
 
-    def get_local_mirror(self):
-        return self.get_mirror_from_availability_zone()
-
-    def get_mirror_from_availability_zone(self, availability_zone=None):
-        # Return type None indicates there is no cloud specific mirror
-        # Availability is like 'us-west-1b' or 'eu-west-1a'
-        if availability_zone is None:
-            availability_zone = self.get_availability_zone()
-
-        if self.is_vpc():
-            return None
-
-        if not availability_zone:
-            return None
-
-        mirror_tpl = self.distro.get_option('package_mirror_ec2_template',
-                                             None)
-
-        if mirror_tpl is None:
-            return None
-
-        # in EC2, the 'region' is 'us-east-1' if 'zone' is 'us-east-1a'
-        tpl_params = {
-            'zone': availability_zone.strip(),
-            'region': availability_zone[:-1]
-        }
-        mirror_url = mirror_tpl % (tpl_params)
-
-        found = util.search_for_mirror([mirror_url])
-        if found is not None:
-            return mirror_url
-
-        return None
-
     def _get_url_settings(self):
         mcfg = self.ds_cfg
         if not mcfg:
@@ -255,6 +221,12 @@ class DataSourceEc2(sources.DataSource):
             return True
         return False
 
+    @property
+    def availability_zone(self):
+        try:
+            return self.metadata['placement']['availability-zone']
+        except KeyError:
+            return None
 
 # Used to match classes to dependencies
 datasources = [
diff --git a/cloudinit/sources/__init__.py b/cloudinit/sources/__init__.py
index ca9f58e5..04296193 100644
--- a/cloudinit/sources/__init__.py
+++ b/cloudinit/sources/__init__.py
@@ -117,9 +117,9 @@ class DataSource(object):
     def get_locale(self):
         return 'en_US.UTF-8'
 
-    def get_local_mirror(self):
-        # ??
-        return None
+    @property
+    def availability_zone(self):
+        return self.metadata.get('availability-zone')
 
     def get_instance_id(self):
         if not self.metadata or 'instance-id' not in self.metadata:
@@ -166,6 +166,10 @@ class DataSource(object):
         else:
             return hostname
 
+    def get_package_mirror_info(self):
+        self.distro.get_package_mirror_info(
+            availability_zone=self.availability_zone)
+
 
 def find_source(sys_cfg, distro, paths, ds_deps, cfg_list, pkg_list):
     ds_list = list_sources(cfg_list, ds_deps, pkg_list)