Make Graphite/Carbon more overridable.

We previously used a less-than-optimal way of storing the configuration
values for Graphite/Carbon, which meant you had to override the entire
configuration (including restating default values, etc) to change one
thing.

This now mirrors how we approach things in the Grafana role, where each
distinct value is a distinct variable that can be overridden separately,
and is pulled together at a higher level into the configuration.

playbooks/roles/graphite/defaults/main.yml

@@ -54,33 +54,54 @@ graphite_group: "graphite"
 GRAPHITE_NGINX_PORT: 6000
 GRAPHITE_GUNICORN_WORKERS: 3
 
-CARBON_LISTEN_ADDR: 0.0.0.0
+carbon_listen_addr: 0.0.0.0
+
+carbon_storage_dir: "{{ graphite_storage_root }}"
+carbon_cache_write_strategy: max
+carbon_max_cache_size: inf
+carbon_use_flow_control: True
+carbon_whisper_fallocate_create: True
+carbon_max_creates_per_minute: 100
+carbon_max_updates_per_second: 1000
+carbon_line_receiver_interface: "{{ carbon_listen_addr }}"
+carbon_pickle_receiver_interface: "{{ carbon_listen_addr }}"
+carbon_cache_query_interface: "{{ carbon_listen_addr }}"
+carbon_use_insecure_unpickler: False
+carbon_log_cache_hits: False
+carbon_log_cache_queue_sorts: True
+carbon_log_listener_connections: True
+carbon_log_updates: False
+carbon_enable_log_rotation: True
+carbon_whisper_autoflush: False
+carbon_default_line_receiver_port: 2003
+carbon_default_pickle_receiver_port: 2004
+carbon_default_cache_query_port: 7002
 
 CARBON_CONF:
   cache:
     USER: "{{ carbon_user }}"
     STORAGE_DIR: "{{ graphite_storage_root }}"
-    CACHE_WRITE_STRATEGY: max
-    MAX_CACHE_SIZE: inf
-    USE_FLOW_CONTROL:  True
-    WHISPER_FALLOCATE_CREATE: True
-    MAX_CREATES_PER_MINUTE: 100
-    MAX_UPDATES_PER_SECOND: 1000
-    LINE_RECEIVER_INTERFACE: "{{ CARBON_LISTEN_ADDR }}"
-    PICKLE_RECEIVER_INTERFACE: "{{ CARBON_LISTEN_ADDR }}"
-    USE_INSECURE_UNPICKLER: False
-    CACHE_QUERY_INTERFACE: "{{ CARBON_LISTEN_ADDR }}"
-    LOG_CACHE_HITS: False
-    LOG_CACHE_QUEUE_SORTS: True
-    LOG_LISTENER_CONNECTIONS: True
-    LOG_UPDATES: False
-    ENABLE_LOGROTATION: True
-    WHISPER_AUTOFLUSH: False
+    CACHE_WRITE_STRATEGY: "{{ carbon_cache_write_strategy }}"
+    MAX_CACHE_SIZE: "{{ carbon_max_cache_size }}"
+    USE_FLOW_CONTROL: "{{ carbon_use_flow_control }}"
+    WHISPER_FALLOCATE_CREATE: "{{ carbon_whisper_fallocate_create }}"
+    MAX_CREATES_PER_MINUTE: "{{ carbon_max_creates_per_minute }}"
+    MAX_UPDATES_PER_SECOND: "{{ carbon_max_updates_per_second }}"
+    LINE_RECEIVER_INTERFACE: "{{ carbon_listen_addr }}"
+    PICKLE_RECEIVER_INTERFACE: "{{ carbon_listen_addr }}"
+    USE_INSECURE_UNPICKLER: "{{ carbon_use_insecure_unpickler }}"
+    CACHE_QUERY_INTERFACE: "{{ carbon_listen_addr }}"
+    LOG_CACHE_HITS: "{{ carbon_log_cache_hits }}"
+    LOG_CACHE_QUEUE_SORTS: "{{ carbon_log_cache_queue_sorts }}"
+    LOG_LISTENER_CONNECTIONS: "{{ carbon_log_listener_connections }}"
+    LOG_UPDATES: "{{ carbon_log_updates }}"
+    ENABLE_LOGROTATION: "{{ carbon_enable_log_rotation }}"
+    WHISPER_AUTOFLUSH: "{{ carbon_whisper_autoflush }}"
 
   "cache:1":
-    LINE_RECEIVER_PORT: 2003
-    PICKLE_RECEIVER_PORT: 2004
-    CACHE_QUERY_PORT: 7002
+    LINE_RECEIVER_PORT: "{{ carbon_default_line_receiver_port }}"
+    PICKLE_RECEIVER_PORT: "{{ carbon_default_line_receiver_port }}"
+    CACHE_QUERY_PORT: "{{ carbon_default_cache_query_port }}"
 
 CARBON_STORAGE_SCHEMAS:
   carbon:
@@ -113,4 +134,4 @@ GRAPHITE_API_CONF:
   search_index: "{{ graphite_root }}/api/index"
   whisper:
     directories:
-      - "{{ graphite_storage_root }}"
+      - "{{ graphite_storage_root }}/whisper"

playbooks/roles/graphite/templates/carbon/conf/storage-aggregation.conf.j2

@@ -11,4 +11,4 @@
 #  xFilesFactor: Ratio of valid data points required for aggregation to the next retention to occur
 #  aggregationMethod: function to apply to data points for aggregation
 
-{{ CARBON_STORAGE_AGGREGATIONS | encode_ini }}
+{{ CARBON_STORAGE_AGGREGATIONS_OVERRIDE | default(CARBON_STORAGE_AGGREGATIONS) | encode_ini }}

playbooks/roles/graphite/templates/carbon/conf/storage-schemas.conf.j2

 # Schema definitions for Whisper files. Entries are scanned in order,
 # and first match wins. This file is scanned for changes every 60 seconds.
 
-{{ CARBON_STORAGE_SCHEMAS | encode_ini }}
+{{ CARBON_STORAGE_SCHEMAS_OVERRIDE | default(CARBON_STORAGE_SCHEMAS) | encode_ini }}