Merge ~cjwatson/launchpad:charm-db-changed into launchpad:master

[Colin Watson]

charm: Clear configured states on DB relation changes

This mainly consists of pulling in a launchpad-layers change that does most of the work, but we also need to add a few handlers for charm-specific combinations of states.

[Guruprasad (lgp171188)]

LGTM 👍🏼

review: Approve

diff --git a/charm/launchpad-admin/charmcraft.yaml b/charm/launchpad-admin/charmcraft.yaml
index 2ce2b19..1f8a8e9 100644
--- a/charm/launchpad-admin/charmcraft.yaml
+++ b/charm/launchpad-admin/charmcraft.yaml
@@ -35,7 +35,7 @@ parts:
     after:
       - ols-layers
     source: https://git.launchpad.net/launchpad-layers
-    source-commit: "22811c726aca173d72ca94f83b35790474847106"
+    source-commit: "0311e05ec2e856e61a2620f68aa3ea35c0a3029b"
     source-submodules: []
     source-type: git
     plugin: dump
diff --git a/charm/launchpad-admin/reactive/launchpad-admin.py b/charm/launchpad-admin/reactive/launchpad-admin.py
index ff76afc..d00383a 100644
--- a/charm/launchpad-admin/reactive/launchpad-admin.py
+++ b/charm/launchpad-admin/reactive/launchpad-admin.py
@@ -12,7 +12,14 @@ from charms.launchpad.base import (
     strip_dsn_authentication,
     update_pgpass,
 )
-from charms.reactive import endpoint_from_flag, set_state, when, when_not
+from charms.reactive import (
+    endpoint_from_flag,
+    remove_state,
+    set_state,
+    when,
+    when_not,
+    when_not_all,
+)
 from ols import base, postgres
 from psycopg2.extensions import make_dsn, parse_dsn
 
@@ -133,3 +140,21 @@ def configure():
 
     set_state("service.configured")
     hookenv.status_set("active", "Ready")
+
+
+@when("service.configured")
+@when_not_all("db-admin.master.available", "session-db.master.available")
+def deconfigure():
+    remove_state("service.configured")
+
+
+@when("db-admin.database.changed", "service.configured")
+def db_admin_changed():
+    remove_state("service.configured")
+    remove_state("db-admin.database.changed")
+
+
+@when("session-db.database.changed", "service.configured")
+def session_db_changed():
+    remove_state("service.configured")
+    remove_state("session-db.database.changed")
diff --git a/charm/launchpad-appserver/charmcraft.yaml b/charm/launchpad-appserver/charmcraft.yaml
index 2fe4e10..47b8752 100644
--- a/charm/launchpad-appserver/charmcraft.yaml
+++ b/charm/launchpad-appserver/charmcraft.yaml
@@ -35,7 +35,7 @@ parts:
     after:
       - ols-layers
     source: https://git.launchpad.net/launchpad-layers
-    source-commit: "22811c726aca173d72ca94f83b35790474847106"
+    source-commit: "0311e05ec2e856e61a2620f68aa3ea35c0a3029b"
     source-submodules: []
     source-type: git
     plugin: dump
diff --git a/charm/launchpad-appserver/reactive/launchpad-appserver.py b/charm/launchpad-appserver/reactive/launchpad-appserver.py
index 1c32282..1edc216 100644
--- a/charm/launchpad-appserver/reactive/launchpad-appserver.py
+++ b/charm/launchpad-appserver/reactive/launchpad-appserver.py
@@ -152,6 +152,18 @@ def check_is_running():
     hookenv.status_set("active", "Ready")
 
 
+@when("service.configured")
+@when_not("session-db.master.available")
+def deconfigure():
+    remove_state("service.configured")
+
+
+@when("session-db.database.changed", "service.configured")
+def session_db_changed():
+    remove_state("service.configured")
+    remove_state("session-db.database.changed")
+
+
 @hook("{requires:memcache}-relation-{joined,changed,broken,departed}")
 def memcache_relation_changed(memcache):
     remove_state("service.configured")
diff --git a/charm/launchpad/charmcraft.yaml b/charm/launchpad/charmcraft.yaml
index 54c5b16..cd51483 100644
--- a/charm/launchpad/charmcraft.yaml
+++ b/charm/launchpad/charmcraft.yaml
@@ -35,7 +35,7 @@ parts:
     after:
       - ols-layers
     source: https://git.launchpad.net/launchpad-layers
-    source-commit: "22811c726aca173d72ca94f83b35790474847106"
+    source-commit: "0311e05ec2e856e61a2620f68aa3ea35c0a3029b"
     source-submodules: []
     source-type: git
     plugin: dump