Call post_init.sh on promote (#238)

This way we can make sure that the recent version of user_management and monitoring functions are deployed.

postgres-appliance/scripts/configure_spilo.py

@@ -236,11 +236,14 @@ def deep_update(a, b):
     replication:
       username: {{PGUSER_STANDBY}}
       password: '{{PGPASSWORD_STANDBY}}'
- {{#CALLBACK_SCRIPT}}
   callbacks:
+  {{#CALLBACK_SCRIPT}}
     on_start: {{CALLBACK_SCRIPT}}
     on_stop: {{CALLBACK_SCRIPT}}
-    on_role_change: {{CALLBACK_SCRIPT}}
+    on_role_change: '/scripts/on_role_change.sh {{HUMAN_ROLE}} {{CALLBACK_SCRIPT}}'
+ {{/CALLBACK_SCRIPT}}
+ {{^CALLBACK_SCRIPT}}
+    on_role_change: '/scripts/on_role_change.sh {{HUMAN_ROLE}} true'
  {{/CALLBACK_SCRIPT}}
 {{#USE_WALE}}
   create_replica_method:

postgres-appliance/scripts/on_role_change.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+readonly HUMAN_ROLE=$1
+shift
+
+"$@"
+
+
+readonly dbname=postgres
+if [[ "${*: -3:1}" == "on_role_change" && "${*: -2:1}" == "master" ]]; then
+    num=30  # wait 30 seconds for end of recovery
+    while  [[ $((num--)) -gt 0 ]]; do
+        if [[ "$(psql -d $dbname -tAc 'SELECT pg_is_in_recovery()')" == "f" ]]; then
+            exec /scripts/post_init.sh "$HUMAN_ROLE" "$dbname"
+        else
+            sleep 1
+        fi
+    done
+fi