Add collector role

Sets up prometheus to pull metrics, with telegraf to process SNMP data.

roles/collector/tasks/main.yml

@@ -0,0 +1,34 @@
+# since this host likely has access to sensitive networks,
+# restrict the destinations where monitoring daemons can connect
+- name: Set up outbound firewall rules
+  copy:
+    dest: "/etc/nftables.d/{{ item }}.nft"
+    src: "{{ item }}.nft"
+  loop:
+    - prometheus
+    - telegraf
+  notify: reload nftables
+
+- name: Configure telegraf to expose SNMP data as prometheus metrics
+  template:
+    dest: "/etc/telegraf.conf.d/{{ item }}.conf"
+    src: "{{ item }}.conf.j2"
+  loop:
+    - output
+    - snmp
+  notify: restart telegraf
+
+- name: Configure prometheus to pull SNMP data
+  copy:
+    dest: "/etc/prometheus/conf.d/snmp.yml"
+    src: "prometheus-snmp.yml"
+  notify: reload prometheus
+
+- name: Configure prometheus to pull custom data
+  template:
+    dest: "/etc/prometheus/conf.d/{{ item.name }}.yml"
+    src: "prometheus-job.yml.j2"
+  loop: "{{ prometheus_hosts }}"
+  loop_control:
+    label: "{{ item.name }}"
+  notify: reload prometheus