Add collector role

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

roles/collector/README.md

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+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:
+
+    {
+        "prometheus_hosts": [
+            {
+                "name": "classroom",
+                "nb_filter": "role=desktop-computer status=active location=classroom"
+            }
+        ],
+        "snmp_hosts": [
+            {
+                "name": "switch",
+                "nb_filter": "role=switch name__isw=sw- status=active status=staged status=planned"
+            }
+        ]
+    }

roles/collector/files/prometheus-snmp.yml

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+scrape_configs:
+  - job_name: "snmp"
+    static_configs:
+      - targets: ["localhost:9273"]

roles/collector/files/prometheus.nft

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+table inet filter {
+    chain output {
+        type filter hook output priority 0; policy accept;
+
+        skuid prometheus ct state { established, related } accept
+        skuid prometheus th dport domain accept
+        skuid prometheus tcp dport { 443, 9100 } accept comment "prometheus"
+        skuid prometheus ip daddr 127.0.0.1 tcp dport 9090 accept comment "prometheus self"
+        skuid prometheus ip daddr 127.0.0.1 tcp dport 9273 accept comment "telegraf snmp exporter"
+        skuid prometheus drop
+    }
+}

roles/collector/files/telegraf.nft

@@ -0,0 +1,9 @@
+table inet filter {
+    chain output {
+        type filter hook output priority 0; policy accept;
+
+        skuid telegraf ct state { established, related } accept
+        skuid telegraf th dport snmp accept
+        skuid telegraf drop
+    }
+}

roles/collector/handlers/main.yml

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+- name: reload nftables
+  service:
+    name: nftables
+    state: reloaded
+  when: "'handler' not in ansible_skip_tags"
+
+- name: reload prometheus
+  service:
+    name: prometheus
+    state: reloaded
+  when: "'handler' not in ansible_skip_tags"
+
+- name: restart telegraf
+  service:
+    name: telegraf
+    state: restarted # seems to crash on reloads
+  when: "'handler' not in ansible_skip_tags"

roles/collector/meta/main.yml

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+dependencies:
+  - role: prometheus
+  - role: telegraf

roles/collector/tasks/main.yml

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+# 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

roles/collector/templates/output.conf.j2

@@ -0,0 +1,4 @@
+[[outputs.prometheus_client]]
+listen = "127.0.0.1:9273"
+expiration_interval = "300s"
+tagexclude = ["mac?"] # temporary tags we don’t need to export

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

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+{% set devices = query("netbox.netbox.nb_lookup", "devices", api_filter="{{ item.nb_filter }}", raw_data=true)
+    | selectattr("primary_ip")
+    | map(attribute="name")
+    | map("extract", hostvars) -%}
+
+scrape_configs:
+  - job_name: "{{ item.name }}"
+    relabel_configs:
+      - source_labels: [__address__]
+        regex: '([^.]+).*'
+        target_label: name
+        replacement: ${1}
+    static_configs:
+      - targets:
+{% for address in devices
+    | selectattr("dns_name", "defined")
+    | map(attribute="dns_name")
+    | reject("none") | sort | unique %}
+          - "{{ address }}:9100"
+{% endfor %}

roles/collector/templates/snmp.conf.j2

@@ -0,0 +1,106 @@
+[[inputs.snmp]]
+  interval = "300s"
+  agent_host_tag = "source"
+  agents = [
+{% for item in snmp_hosts %}
+{% 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") %}
+    "{{ address }}",
+{% endfor %}
+{% endfor %}
+  ]
+  version = 3
+  sec_level = "authPriv"
+  auth_protocol = "SHA"
+  priv_protocol = "DES"
+  sec_name = "{{ password.snmp_user }}"
+  auth_password = "{{ password.snmp_pass }}"
+  priv_password = "{{ password.snmp_pass }}"
+
+  fieldexclude = ["ifDescr", "ifSpecific"]
+
+  [[inputs.snmp.field]]
+    name = "hostname"
+    oid = "RFC1213-MIB::sysName.0"
+    is_tag = true
+
+  # interface table
+  [[inputs.snmp.table]]
+    name = "iface"
+    oid = "IF-MIB::ifTable"
+    inherit_tags = ["hostname"]
+
+    [[inputs.snmp.table.field]]
+      oid = "IF-MIB::ifName"
+
+    # rename counters to make prometheus happy
+    [[inputs.snmp.table.field]]
+      name = "in_total"
+      oid = "IF-MIB::ifInOctets"
+
+    [[inputs.snmp.table.field]]
+      name = "in_err_total"
+      oid = "IF-MIB::ifInErrors"
+
+    [[inputs.snmp.table.field]]
+      name = "out_total"
+      oid = "IF-MIB::ifOutOctets"
+
+    [[inputs.snmp.table.field]]
+      name = "out_err_total"
+      oid = "IF-MIB::ifOutErrors"
+
+  # MAC address table per VLAN
+  [[inputs.snmp.table]]
+    name = "fdb"
+    index_as_tag = true
+    inherit_tags = ["hostname"]
+
+    [[inputs.snmp.table.field]]
+      name = "ifIndex"
+      oid = "Q-BRIDGE-MIB::dot1qTpFdbPort"
+      is_tag = true
+
+    [[inputs.snmp.table.field]]
+      name = "entry"
+      oid = "Q-BRIDGE-MIB::dot1qTpFdbStatus"
+
+# look up interface name from its index
+# seems we need another SNMP connection for that
+[[processors.snmp_lookup]]
+  namepass = ["fdb", "iface"]
+  agent_tag = "source"
+  index_tag = "ifIndex"
+
+  version = 3
+  sec_level = "authPriv"
+  auth_protocol = "SHA"
+  priv_protocol = "DES"
+  sec_name = "{{ password.snmp_user }}"
+  auth_password = "{{ password.snmp_pass }}"
+  priv_password = "{{ password.snmp_pass }}"
+
+  [[processors.snmp_lookup.tag]]
+  oid = "IF-MIB::ifName"
+  name = "iface"
+
+# split index 42.1.2.3.10.11.12 into tags "vlan" and "mac1" to "mac6"
+[[processors.regex]]
+  namepass = ["fdb"]
+
+  [[processors.regex.tags]]
+  key = "index"
+  pattern = '^(?P<vlan>\d+)\.(?P<mac1>\d+)\.(?P<mac2>\d+)\.(?P<mac3>\d+)\.(?P<mac4>\d+)\.(?P<mac5>\d+)\.(?P<mac6>\d+)'
+
+# combine "mac*" tags into a single tag "mac" with value 01:02:03:0a:0b:0c
+[[processors.template]]
+  namepass = ["fdb"]
+  tagexclude = ["ifIndex", "index"]
+  tag = "mac"
+{% raw %}
+  template = '''{{
+    printf "%02x:%02x:%02x:%02x:%02x:%02x"
+        (.Tag "mac1"|int) (.Tag "mac2"|int) (.Tag "mac3"|int) (.Tag "mac4"|int) (.Tag "mac5"|int) (.Tag "mac6"|int)
+  }}'''
+{% endraw %}

roles/prometheus/README.md

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+Install and configure prometheus.
+
+Job definitions should be placed in /etc/prometheus/conf.d by roles using this one.

roles/prometheus/files/prometheus.yml

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+scrape_config_files:
+  - "conf.d/*.yml"

roles/prometheus/handlers/main.yml

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+- name: reload prometheus
+  service:
+    name: prometheus
+    state: reloaded
+  when: "'handler' not in ansible_skip_tags"

roles/prometheus/tasks/main.yml

@@ -0,0 +1,21 @@
+- name: Install packages
+  package:
+    name:
+      - prometheus
+
+- name: Create directory for prometheus configs
+  file:
+    path: /etc/prometheus/conf.d
+    state: directory
+
+- name: Configure prometheus
+  copy:
+    dest: /etc/prometheus/
+    src: prometheus.yml
+  notify: reload prometheus
+
+- name: Enable prometheus service
+  service:
+    name: prometheus
+    enabled: true
+    state: started

roles/telegraf/tasks/debian.yml

@@ -1,31 +0,0 @@
-- name: Add influxdb repository
-  deb822_repository:
-    name: influxdata
-    uris: https://repos.influxdata.com/debian
-    suites: stable
-    components: main
-    architectures: amd64
-    signed_by: https://repos.influxdata.com/influxdata-archive.key
-  notify: update package cache
-
-- meta: flush_handlers
-
-- name: Install telegraf
-  package:
-    name: telegraf
-
-- name: Configure telegraf
-  when: not ansible_check_mode
-  template:
-    dest: /etc/telegraf/telegraf.d/output.conf
-    src: output.conf.j2
-    owner: telegraf
-    group: telegraf
-    mode: 0640
-  notify: restart telegraf
-
-- name: Enable telegraf
-  service:
-    name: telegraf
-    enabled: true
-    state: started

roles/telegraf/tasks/main.yml

@@ -1,11 +1,22 @@
-- name: Get influxdb info
+- name: Add telegraf package repo on Debian
-  set_fact:
-    influxdb_info: '{{ lookup("passwordstore", "vm/"~influxdb_host, returnall=true, missing="empty") | from_yaml }}'
-
-- name: Create influxdb token for this host
-  include_tasks: token.yml
-  when: 'not ansible_check_mode and "influxdb_token" not in password'
-
-- name: Install telegraf on Debian
-  include_tasks: debian.yml
   when: ansible_os_family == "Debian"
+  deb822_repository:
+    name: influxdata
+    uris: https://repos.influxdata.com/debian
+    suites: stable
+    components: main
+    architectures: amd64
+    signed_by: https://repos.influxdata.com/influxdata-archive.key
+  notify: update package cache
+
+- meta: flush_handlers
+
+- name: Install telegraf
+  package:
+    name: telegraf
+
+- name: Enable telegraf service
+  service:
+    name: telegraf
+    enabled: true
+    state: started

roles/telegraf/tasks/token.yml

@@ -1,53 +0,0 @@
-- name: Get influxdb organization ID
-  delegate_to: localhost
-  uri:
-    url: '{{ influxdb_info.influxdb_url }}/api/v2/orgs'
-    headers:
-      Authorization: Token {{ influxdb_info.influxdb_operator_token }}
-  register: response
-
-- name: Parse influxdb orgID
-  set_fact:
-    influxdb_orgID: '{{ response.json.orgs | selectattr("name", "==", influxdb_info.influxdb_org) | map(attribute="id") | first }}'
-
-- name: Get influxdb bucket ID
-  delegate_to: localhost
-  uri:
-    url: '{{ influxdb_info.influxdb_url }}/api/v2/buckets?orgID={{ influxdb_orgID }}'
-    headers:
-      Authorization: Token {{ influxdb_info.influxdb_operator_token }}
-  register: response
-
-- name: Parse influxdb bucketID
-  set_fact:
-    influxdb_bucketID: '{{ response.json.buckets | selectattr("name", "==", "servers") | map(attribute="id") | first }}'
-
-- name: Create influxdb token
-  delegate_to: localhost
-  uri:
-    url: '{{ influxdb_info.influxdb_url }}/api/v2/authorizations'
-    method: POST
-    body_format: json
-    status_code: 201
-    headers:
-      Authorization: Token {{ influxdb_info.influxdb_operator_token }}
-      Content-Type: application/json
-    body: |
-      {
-        "description": "{{ inventory_hostname }}",
-        "orgID": "{{ influxdb_orgID }}",
-        "permissions": [{ "action": "write", "resource": { "type": "buckets", "id": "{{ influxdb_bucketID }}" } }]
-      }
-  register: response
-
-- name: Parse influxdb token
-  set_fact:
-    influxdb_token: '{{ response.json.token }}'
-
-# Ansible’s passwordstore lookup plugin should be able to do that but is pretty broken,
-# so we do it manually.
-- name: Store influxdb token in password store
-  delegate_to: localhost
-  command:
-    cmd: 'pass insert --force --multiline {{ ("vm/" if is_virtual else "host/")~inventory_hostname }}'
-    stdin: '{{ password | to_nice_yaml(sort_keys=false) }}influxdb_token: {{ influxdb_token }}'

roles/telegraf/templates/output.conf.j2

@@ -1,5 +0,0 @@
-[[outputs.influxdb_v2]]
- urls = ["{{ influxdb_info.influxdb_url }}"]
- organization = "{{ influxdb_info.influxdb_org }}"
- bucket = "{{ influxdb_info.influxdb_bucket }}"
- token = "{{ influxdb_token | default(password.influxdb_token) }}"

setup.yml

@@ -16,12 +16,12 @@
 - hosts: ceph-*
   roles:
     - frr
-    - telegraf
     - ceph
 
 - hosts: mgmt-gw
   roles:
     - radvd # we are router for mgmt networks
+    - collector
 
 - hosts: proxmox-backup
   roles: