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)
   * 'ec2_region' substitution variable is present only if this
     appears (by availability-zone naming convention) to be in EC2.
 * 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.
 * package_mirrors is now required in the system_info config, a dict like:
   package_mirrors:
     - arches: [i386, amd64]
       failsafe:
         primary: http://archive.ubuntu.com/ubuntu
         security: http://security.ubuntu.com/ubuntu
       search:
         primary:
           - http://%(ec2_region)s.ec2.archive.ubuntu.com/ubuntu/
           - http://%(availability_zone)s.clouds.archive.ubuntu.com/ubuntu/
         security: []
     - arches: [armhf, armel, default]
       failsafe:
         primary: http://ports.ubuntu.com/ubuntu
         security: http://ports.ubuntu.com/ubuntu

LP: #1006963, #1028501, #1037727

1 files changed, 6 insertions, 34 deletions

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 = [