Whitelist the public_ips of every inventory host in crowdsec and keep a LAPI allowlist equal to the whitelist

crowdsec/defaults/main.yml

@@ -10,8 +10,15 @@ crowdsec:
   scenarios: {}
   # path below /etc/crowdsec -> content, for local parsers and scenarios.
   local_files: {}
-  # name -> CIDR (single addresses as /32 or /128) never acted upon by this agent.
+  # name -> CIDR (single addresses as /32 or /128) never acted upon. Joined by
+  # the public_ips (same format) of every inventory host, then whitelisted by
+  # this agent and, when lapi_allowlist is set, allowlisted on the LAPI.
   whitelist: {}
+  # LAPI allowlist kept equal to the whitelist; it also drops alerts on ranges
+  # holding a whitelisted address, which a parser whitelist cannot.
+  lapi_allowlist: ""
+  # Host whose k3s kubectl reaches the LAPI pod (crowdsec/crowdsec-lapi).
+  lapi_kubectl_host: ""
   # name -> acquisition datasource, written to /etc/crowdsec/acquis.d/<name>.yaml.
   acquisition: {}
   # packagecloud has no trixie suite yet; the bookworm build is static Go.

crowdsec/tasks/main.yml

@@ -187,3 +187,37 @@
     enabled: true
     state: started
   loop: [crowdsec.service, crowdsec-firewall-bouncer.service]
+
+- name: Sync the LAPI allowlist
+  when: crowdsec.lapi_allowlist | length > 0
+  run_once: true
+  delegate_to: "{{ crowdsec.lapi_kubectl_host }}"
+  vars:
+    crowdsec_lapi_cscli: k3s kubectl -n crowdsec exec deploy/crowdsec-lapi -c crowdsec-lapi -- cscli
+  block:
+    - name: Read the LAPI allowlist
+      ansible.builtin.command: "{{ crowdsec_lapi_cscli }} allowlists inspect {{ crowdsec.lapi_allowlist }} -o json"
+      register: crowdsec_allowlist_json
+      changed_when: false
+      failed_when: false
+      check_mode: false
+
+    - name: Create the LAPI allowlist
+      ansible.builtin.command: >-
+        {{ crowdsec_lapi_cscli }} allowlists create {{ crowdsec.lapi_allowlist }}
+        -d "Internal ranges and the public addresses of all hosts, managed by Ansible"
+      when: crowdsec_allowlist_json.rc != 0
+
+    # cscli stores single addresses without their /32 or /128.
+    - name: Update the LAPI allowlist
+      ansible.builtin.command: "{{ crowdsec_lapi_cscli }} allowlists {{ item.action }} {{ crowdsec.lapi_allowlist }} {{ item.cidrs | join(' ') }}"
+      vars:
+        crowdsec_allowlist_wanted: "{{ crowdsec_whitelist | map('regex_replace', '/(32|128)$', '') | list }}"
+        crowdsec_allowlist_present: >-
+          {{ ((crowdsec_allowlist_json.stdout | default('{}', true) | from_json).get('items') or []) | map(attribute='value') | list }}
+      loop:
+        - { action: add, cidrs: "{{ crowdsec_allowlist_wanted | difference(crowdsec_allowlist_present) }}" }
+        - { action: remove, cidrs: "{{ crowdsec_allowlist_present | difference(crowdsec_allowlist_wanted) }}" }
+      loop_control:
+        label: "{{ item.action }} {{ item.cidrs | join(' ') }}"
+      when: item.cidrs | length > 0

crowdsec/templates/whitelist.yaml.j2

@@ -1,9 +1,9 @@
 # {{ ansible_managed }}
 name: local/host-whitelist
-description: Internal ranges and admin addresses
+description: Internal ranges and the public addresses of all hosts
 whitelist:
   reason: internal or admin source
   cidr:
-{% for cidr in crowdsec.whitelist | dict2items | rejectattr('value', 'none') | map(attribute='value') | unique %}
+{% for cidr in crowdsec_whitelist %}
     - "{{ cidr }}"
 {% endfor %}

crowdsec/vars/main.yml

@@ -0,0 +1,4 @@
+---
+crowdsec_whitelist: >-
+  {{ (crowdsec.whitelist | dict2items | rejectattr('value', 'none') | map(attribute='value') | list
+  + groups['all'] | map('extract', hostvars, 'public_ips') | select('defined') | flatten) | unique }}