service: add storage-capacity, use instead of static radius

Static radius will cause the database to grow as the total
content on the network grows. This was fine in the beginning
to ensure enough nodes had the content but becomes impossible to
maintain now that the network is growing substancially.
Instead we now set it to a fixed max storage capacity.

Signed-off-by: Jakub Sokołowski <jakub@status.im>

defaults/main.yml

@@ -46,7 +46,8 @@ nimbus_fluffy_listening_port: 9009
 nimbus_fluffy_table_ip_limit: 1024
 nimbus_fluffy_bucket_ip_limit: 24
 nimbus_fluffy_bits_per_hop: 1
-nimbus_fluffy_radius: 'static:252'
+nimbus_fluffy_radius: 'dynamic'
+nimbus_fluffy_storage_capacity: 35000 # in megabytes
 
 # Metrics
 nimbus_fluffy_metrics_enabled: true

templates/fluffy.service.j2

@@ -32,7 +32,8 @@ ExecStart={{ nimbus_fluffy_binary_path }} \
   --table-ip-limit={{ nimbus_fluffy_table_ip_limit }} \
   --bucket-ip-limit={{ nimbus_fluffy_bucket_ip_limit }} \
   --bits-per-hop={{ nimbus_fluffy_bits_per_hop }} \
-  --radius={{ nimbus_fluffy_radius }}
+  --radius={{ nimbus_fluffy_radius }} \
+  --storage-capacity={{ nimbus_fluffy_storage_capacity }}
 
 [Install]
 WantedBy=multi-user.target