collector: support custom poll intervals

Also simplify config context schema for SNMP since we only use a single
instance.

roles/collector/README.md

@@ -1,18 +1,19 @@
 Set up metric collection with prometheus and telegraf as the SNMP proxy.
 
-NetBox config context should contain the lists `prometheus_hosts` and `snmp_hosts` with job definitions. Each entry should define `name` and `nb_filter` user to query hosts from NetBox. For example:
+Each entry in `prometheus_config` should define `name`, `hosts` and optionally `interval`. As above, `hosts` is used as a query filter.
+
+For SNMP the properties `snmp_hosts` and optional `snmp_interval` should define respectively the NetBox query filter and poll interval.
+
+For example:
 
     {
-        "prometheus_hosts": [
+        "prometheus_config": [
             {
                 "name": "classroom",
-                "nb_filter": "role=desktop-computer status=active location=classroom"
+                "hosts": "role=desktop-computer status=active location=classroom",
+                "interval": 300
             }
         ],
-        "snmp_hosts": [
+        "snmp_hosts": "role=switch name__isw=sw- status=active status=staged status=planned",
-            {
+        "snmp_interval": 300
-                "name": "switch",
-                "nb_filter": "role=switch name__isw=sw- status=active status=staged status=planned"
-            }
-        ]
     }

roles/collector/tasks/main.yml

@@ -28,7 +28,7 @@
   template:
     dest: "/etc/prometheus/conf.d/{{ item.name }}.yml"
     src: "prometheus-job.yml.j2"
-  loop: "{{ prometheus_hosts }}"
+  loop: "{{ prometheus_config }}"
   loop_control:
     label: "{{ item.name }}"
   notify: reload prometheus

roles/collector/templates/prometheus-job.yml.j2

@@ -1,10 +1,14 @@
-{% set devices = query("netbox.netbox.nb_lookup", "devices", api_filter="{{ item.nb_filter }}", raw_data=true)
+{% set devices = query("netbox.netbox.nb_lookup", "devices", api_filter="{{ item.hosts }}", raw_data=true)
     | selectattr("primary_ip")
     | map(attribute="name")
     | map("extract", hostvars) -%}
 
 scrape_configs:
   - job_name: "{{ item.name }}"
+{% if item.interval is defined %}
+    scrape_interval: {{ item.interval }}s
+    scrape_timeout: {{ item.interval // 5 }}s
+{% endif %}
     relabel_configs:
       - source_labels: [__address__]
         regex: '([^.]+).*'

roles/collector/templates/snmp.conf.j2

@@ -1,13 +1,13 @@
 [[inputs.snmp]]
-  interval = "300s"
+{% if snmp_interval is defined %}
+  interval = "{{ snmp_interval }}s"
+{% endif %}
   agent_host_tag = "source"
   agents = [
-{% for item in snmp_hosts %}
+{% for address in query("netbox.netbox.nb_lookup", "devices", api_filter=snmp_hosts, raw_data=true)
-{% for address in query("netbox.netbox.nb_lookup", "devices", api_filter=item.nb_filter, raw_data=true)
     | selectattr("primary_ip4") | map(attribute="primary_ip4.address")
-    | ipaddr("address") %}
+    | ipaddr("int") | sort | ipaddr("address") %}
     "{{ address }}",
-{% endfor %}
 {% endfor %}
   ]
   version = 3