Merge ~hloeung/influxdb-charm:master into influxdb-charm:master

[Haw Loeung]

Allow overriding max-series-per-database.

[Paul Gear (paulgear)]

LGTM

review: Approve

diff --git a/config.yaml b/config.yaml
index 88e99ce..ce9ee4a 100644
--- a/config.yaml
+++ b/config.yaml
@@ -75,3 +75,7 @@ options:
         databases to the nominated directory.  See
         https://docs.influxdata.com/influxdb/v1.3/administration/backup_and_restore/
         for more information on InfluxDB backups.
+  max_series_per_database:
+    type: int
+    default: 1000000
+    description: "Maximum series allowed per database before writes are dropped"
diff --git a/reactive/influxdb.py b/reactive/influxdb.py
index d7698cf..856c9bb 100644
--- a/reactive/influxdb.py
+++ b/reactive/influxdb.py
@@ -33,11 +33,12 @@ def install_influx():
     set_state('influxdb.configured')
 
 
-@when_any('config.changed.bind_port', 'config.changed.ip_address')
+@when_any('config.changed.bind_port', 'config.changed.ip_address', 'config.changed.max_series_per_database')
 def config_changed():
     config = hookenv.config()
     port = config.get('bind_port')
     ip_address = config.get('ip_address')
+    max_series_per_database = config.get('max_series_per_database')
     render(source='influxdb.conf',
            target='/etc/influxdb/influxdb.conf',
            owner='root',
@@ -46,6 +47,7 @@ def config_changed():
                'admin': 'true',
                'bind_port': port,
                'ip_address': ip_address,
+               'max_series_per_database': max_series_per_database,
            })
     service_stop('influxdb')
     service_start('influxdb')
diff --git a/templates/influxdb.conf b/templates/influxdb.conf
index 675ce90..77ed982 100644
--- a/templates/influxdb.conf
+++ b/templates/influxdb.conf
@@ -80,7 +80,7 @@
   # The maximum series allowed per database before writes are dropped.  This limit can prevent
   # high cardinality issues at the database level.  This limit can be disabled by setting it to
   # 0.
-  # max-series-per-database = 1000000
+  max-series-per-database = {{max_series_per_database}}
 
   # The maximum number of tag values per tag that are allowed before writes are dropped.  This limit
   # can prevent high cardinality tag values from being written to a measurement.  This limit can be