Merge ~barryprice/charm-canonical-livepatch/+git/canonical-livepatch-charm:master into ~livepatch-charmers/charm-canonical-livepatch:master

[Barry Price]

Use reactive triggers to handle proxy setting, avoid handling the reconfig/restart logic twice

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

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

[Stuart Bishop (stub)]

Looks good to me.

review: Approve

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

Change successfully merged at revision 9635b94b1f64a01b2d51cd13f542d8b4cbc6587b

diff --git a/reactive/canonical_livepatch.py b/reactive/canonical_livepatch.py
index f71923d..7c0b559 100644
--- a/reactive/canonical_livepatch.py
+++ b/reactive/canonical_livepatch.py
@@ -1,5 +1,6 @@
 from charms import layer
-from charms.reactive import when, when_not, set_state, remove_state
+from charms.reactive import when, when_not, set_flag, clear_flag
+from charms.reactive.flags import register_trigger
 from charmhelpers.core.host import write_file, is_container
 from charmhelpers.core import hookenv
 from charmhelpers.contrib.charmsupport import nrpe
@@ -167,17 +168,21 @@ def activate_livepatch():
             check_output(cmd, universal_newlines=True)
         except CalledProcessError as e:
             hookenv.log('Unable to activate: {}'.format(str(e)), hookenv.ERROR)
-            remove_state('canonical-livepatch.active')
+            clear_flag('canonical-livepatch.active')
             unit_update('blocked', 'Activation failed')
         else:
-            set_state('canonical-livepatch.active')
+            set_flag('canonical-livepatch.active')
+            clear_flag('canonical-livepatch.restart-needed')
             unit_update()
     else:
         hookenv.log('Unable to activate canonical-livepatch as no key has been set', hookenv.ERROR)
-        remove_state('canonical-livepatch.active')
+        clear_flag('canonical-livepatch.active')
         unit_update('blocked', 'Service disabled, please set livepatch_key to activate')
 
 
+register_trigger(when='config.changed.livepatch_proxy', clear_flag='livepatch-proxy.configured')
+
+
 @when_not('snap.installed.canonical-livepatch')
 def livepatch_supported():
     arch = uname()[4]
@@ -191,7 +196,19 @@ def livepatch_supported():
         unit_update('blocked', 'Livepatch is not needed in OS containers')
 
 
+@when_not('livepatch-proxy.configured')
+def proxy_configure():
+    # Configure proxies early, if required - LP#1761661
+    config = hookenv.config()
+    proxy_url = config.get('livepatch_proxy')
+    if proxy_url:
+        configure_proxies(http_proxy=proxy_url, https_proxy=proxy_url)
+    set_flag('livepatch-proxy.configured')
+    set_flag('canonical-livepatch.restart-needed')
+
+
 @when('snap.installed.canonical-livepatch')
+@when('livepatch-proxy.configured')
 @when_not('canonical-livepatch.connected')
 def canonical_livepatch_connect():
     # So if we've just installed snapd on a trusty system, we will not be on
@@ -207,14 +224,9 @@ def canonical_livepatch_connect():
         unit_update('blocked', 'A reboot is required')
     else:
         unit_update('maintenance', 'Connecting to the livepatch service')
-        # Configure proxies early, if required - LP#1761661
-        config = hookenv.config()
-        proxy_url = config.get('livepatch_proxy')
-        if proxy_url:
-            configure_proxies(http_proxy=proxy_url, https_proxy=proxy_url)
         # Make sure the service is ready for us
         wait_for_livepatch()
-        set_state('canonical-livepatch.connected')
+        set_flag('canonical-livepatch.connected')
         unit_update('blocked', 'Service disabled, please set livepatch_key to activate')
 
 
@@ -233,12 +245,9 @@ def update_key():
     activate_livepatch()
 
 
-@when('canonical-livepatch.connected', 'config.changed.livepatch_proxy')
-def update_livepatch_proxy():
-    unit_update('maintenance', 'Configuring proxy servers')
-    config = hookenv.config()
-    proxy_url = config.get('livepatch_proxy')
-    configure_proxies(http_proxy=proxy_url, https_proxy=proxy_url)
+@when('canonical-livepatch.connected', 'canonical-livepatch.restart-needed')
+def handle_restart():
+    unit_update('maintenance', 'Restarting client')
 
     # restart the system service to pick up the new config
     restart_livepatch()
@@ -290,7 +299,7 @@ def configure_nagios(nagios):
     nrpe_setup.write()
 
     # Remove obsolete state from older charm.
-    remove_state('canonical-livepatch.nagios-configured')
+    clear_flag('canonical-livepatch.nagios-configured')
 
 
 @when('snap.installed.canonical-livepatch', 'canonical-livepatch.active')