Series Upgrade

Implement the series-upgrade feature allowing to move between Ubuntu
series.

Change-Id: I9efe27463471fdc99f794931ee03db0bd1e06fbd

hooks/lxd_hooks.py

@@ -56,6 +56,13 @@ from charmhelpers.fetch import (
     add_source,
 )
 
+from charmhelpers.contrib.openstack.utils import (
+    clear_unit_paused,
+    clear_unit_upgrading,
+    set_unit_paused,
+    set_unit_upgrading,
+)
+
 hooks = Hooks()
 
 
@@ -133,6 +140,27 @@ def lxd_migration_relation_changed(rid=None, unit=None):
         [configure_lxd_remote(settings, u) for u in users]
 
 
+@hooks.hook('pre-series-upgrade')
+def pre_series_upgrade():
+    log("Running prepare series upgrade hook", "INFO")
+    # NOTE: The Ceph packages handle the series upgrade gracefully.
+    # In order to indicate the step of the series upgrade process for
+    # administrators and automated scripts, the charm sets the paused and
+    # upgrading states.
+    set_unit_paused()
+    set_unit_upgrading()
+
+
+@hooks.hook('post-series-upgrade')
+def post_series_upgrade():
+    log("Running complete series upgrade hook", "INFO")
+    # In order to indicate the step of the series upgrade process for
+    # administrators and automated scripts, the charm clears the paused and
+    # upgrading states.
+    clear_unit_paused()
+    clear_unit_upgrading()
+
+
 def main():
     try:
         hooks.execute(sys.argv)
@@ -140,5 +168,6 @@ def main():
         log("Unknown hook {} - skipping.".format(e))
     assess_status()
 
+
 if __name__ == "__main__":
     main()

hooks/lxd_utils.py

@@ -50,6 +50,9 @@ from charmhelpers.core.host import (
     is_container,
     CompareHostReleases,
 )
+from charmhelpers.contrib.openstack.utils import (
+    is_unit_upgrading_set,
+)
 from charmhelpers.contrib.storage.linux.utils import (
     is_block_device,
     zap_disk,
@@ -543,7 +546,11 @@ def lxd_start():
 
 def assess_status():
     '''Determine status of current unit'''
-    if lxd_running():
+    if is_unit_upgrading_set():
+        status_set('blocked',
+                   'Ready for do-release-upgrade and reboot. '
+                   'Set complete when finished.')
+    elif lxd_running():
         status_set('active', 'Unit is ready')
     else:
         status_set('blocked', 'LXD is not running')
@@ -566,6 +573,7 @@ def zpools():
     except CalledProcessError:
         return []
 
+
 SUBUID = '/etc/subuid'
 SUBGID = '/etc/subgid'
 DEFAULT_COUNT = '327680000'  # 5000 containers

hooks/post-series-upgrade

@@ -0,0 +1 @@
+lxd_hooks.py

hooks/pre-series-upgrade

@@ -0,0 +1 @@
+lxd_hooks.py