Merge lp:~danilo/charms/trusty/glance-simplestreams-sync/conditional-endpoint-update into lp:~landscape/charms/trusty/glance-simplestreams-sync/landscape

[Данило Шеган]

Only update (delete/create) "image-stream" endpoint if different from values we want to set it to

This will reduce the changes of hitting a race on keystone units during Autopilot installation: instead of doing delete/create dance every time, we only do it when really needed.

Testing instructions:

1. Deploy OPL
2. Modify canonical/landscape/model/openstack/charms/trusty-stable.json to point at
    cs:~danilo/trusty/glance-simplestreams-sync-26
3. Deploy Autopilot (swift and ceph for object store will use different endpoints, so might be worth re-testing both, even though we do not change that part of the logic)
4. Watch for logging messages about not updating the endpoint ("Endpoint already set to desired values, moving on.") in /var/log/glance-simplestreams-sync.log on gs3 unit
5. Check that things like juju bootstrap still work, that images are correctly synced, etc.

[Geoff Teale (tealeg)]

+1 This looks great. Especially like the use of all(), because I'm a sucker for that stuff ;-)

review: Approve

[Bogdana Vereha (bogdana)]

+1

review: Approve

[Данило Шеган (danilo)]

Merged and published as cs:~landscape-charmers/xenial/glance-simplestreams-sync-4 and cs:~landscape-charmers/trusty/glance-simplestreams-sync-10

=== modified file 'scripts/glance-simplestreams-sync.py'
--- scripts/glance-simplestreams-sync.py	2016-05-23 14:40:23 +0000
+++ scripts/glance-simplestreams-sync.py	2016-05-24 07:54:10 +0000
@@ -45,7 +45,6 @@
 
 import atexit
 import fcntl
-import glanceclient
 from keystoneclient.v2_0 import client as keystone_client
 import keystoneclient.exceptions as keystone_exceptions
 import kombu
@@ -53,13 +52,10 @@
 from simplestreams.mirrors import glance, UrlMirrorReader
 from simplestreams.objectstores.swift import SwiftObjectStore
 from simplestreams.util import read_signed, path_from_mirror_url
-import swiftclient
 import sys
 import time
 import traceback
 import yaml
-import requests
-import requests.exceptions
 import subprocess
 
 KEYRING = '/usr/share/keyrings/ubuntu-cloudimage-keyring.gpg'
@@ -253,20 +249,28 @@
                     " endpoint".format(len(ps_endpoints), region))
         return
 
-    log.info("Deleting existing product-streams endpoint: ")
-    ksc.endpoints.delete(ps_endpoints[0]['id'])
-
     create_args = dict(region=region,
                        service_id=ps_service_id,
                        publicurl=catalog['publicURL'],
                        adminurl=catalog['adminURL'],
                        internalurl=catalog['internalURL'])
-    status_set('maintenance', 'Updating product-streams endpoint')
-    log.info("creating product-streams endpoint: {}".format(create_args))
-    ksc.endpoints.create(**create_args)
-    update_endpoint_urls(region, catalog['publicURL'],
-                         catalog['adminURL'],
-                         catalog['internalURL'])
+    ps_endpoint = ps_endpoints[0]
+
+    endpoint_already_exists = all(
+        create_args[key] == ps_endpoint.get(key) for key in create_args)
+
+    if endpoint_already_exists:
+        log.info("Endpoint already set to desired values, moving on.")
+    else:
+        status_set('maintenance', 'Updating product-streams endpoint')
+
+        log.info("Deleting existing product-streams endpoint: ")
+        ksc.endpoints.delete(ps_endpoints[0]['id'])
+        log.info("creating product-streams endpoint: {}".format(create_args))
+        ksc.endpoints.create(**create_args)
+        update_endpoint_urls(region, catalog['publicURL'],
+                             catalog['adminURL'],
+                             catalog['internalURL'])
 
 
 def juju_run_cmd(cmd):
@@ -288,7 +292,7 @@
 
 def update_endpoint_urls(region, publicurl, adminurl, internalurl):
     # Notify keystone via the identity service relation about
-    # and endpoint changes
+    # any endpoint changes.
     for rid in juju_run_cmd(['relation-ids', 'identity-service']).split():
         log.info("Updating relation data for: {}".format(rid))
         _cmd = ['relation-set', '-r', rid]
@@ -446,7 +450,8 @@
         # If this is an initial per-minute sync attempt, delete it on success.
         if os.path.exists(CRON_POLL_FILENAME):
             os.unlink(CRON_POLL_FILENAME)
-            log.info("Initial sync attempt done. every-minute cronjob removed.")
+            log.info(
+                "Initial sync attempt done: every-minute cronjob removed.")
 
     except keystone_exceptions.EndpointNotFound as e:
         # matching string "{PublicURL} endpoint for {type}{region} not