Merge ~hloeung/ubuntu-repository-cache:fixes into ubuntu-repository-cache:master

[Haw Loeung]

Fix to handle cases when datasource is null

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[James Simpson (jsimpso)]

LGTM

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision d1273c26293afbf503a317372fb7dc8862ab4846

diff --git a/lib/ubuntu_repository_cache/apache.py b/lib/ubuntu_repository_cache/apache.py
index a674370..0ce7cee 100644
--- a/lib/ubuntu_repository_cache/apache.py
+++ b/lib/ubuntu_repository_cache/apache.py
@@ -3,7 +3,6 @@
 import multiprocessing
 import os
 import subprocess
-import json
 
 from charmhelpers import fetch
 
@@ -340,29 +339,22 @@ def update_checks(nrpe_config):
     '''Update nagios check for apache serving archive metadata'''
 
     path_base = hookenv.config()['path-base']
-    try:
-        with open('/run/cloud-init/status.json') as status:
-            status_json = json.load(status)
-    except OSError:
-        pass
-    else:
-        # try to find proof we're in Azure
-        # in any version of the status json
-        if any('DataSourceAzure' in x.get('datasource', '') for x in status_json.values()):
-            # In azure, we rely on cloud services
-            # instead of doing our own haproxy work
-            nrpe_config.add_check(
-                shortname='load-balancer',
-                description='e2e check that regional load balancer is functioning',
-                check_cmd=(
-                    'check_http '
-                    '--hostname ubuntu-archive-asm.trafficmanager.net '
-                    '--url "/{}/" '
-                    '--string "dists/" '
-                    '--expect 200\\ OK '
-                    '--header Accept-Encoding:\\ \\*'
-                ).format(path_base),
-            )
+
+    # In azure, we rely on cloud services instead of doing our own
+    # haproxy work.
+    if os.path.exists('/run/cloud-init/cloud-id-azure'):
+        nrpe_config.add_check(
+            shortname='load-balancer',
+            description='e2e check that regional load balancer is functioning',
+            check_cmd=(
+                'check_http '
+                '--hostname ubuntu-archive-asm.trafficmanager.net '
+                '--url "/{}/" '
+                '--string "dists/" '
+                '--expect 200\\ OK '
+                '--header Accept-Encoding:\\ \\*'
+            ).format(path_base),
+        )
 
     nrpe_config.add_check(
         shortname='apache',