Add `state` option for removing exporters

3 files changed, 51 insertions, 7 deletions

diff --git a/tasks/process_exporter.yml b/tasks/process_exporter.yml
index b4f33ba..0a19480 100644
--- a/tasks/process_exporter.yml
+++ b/tasks/process_exporter.yml
@@ -12,6 +12,13 @@
       {{ (item.host if item.host is defined else _defaults.host) | mandatory }}
     _target_labels: >-
       {{ (_defaults.labels | default({})) | combine(item.labels | default({})) }}
+    _target_state: >-
+      {{ item.state if item.state is defined else (_defaults.state | default('present')) }}
+
+- name: Validate exporter state
+  ansible.builtin.assert:
+    that: _target_state in ["present", "absent"]
+    fail_msg: "Exporter state must be 'present' or 'absent', got '{{ _target_state }}'"
 
 - name: Execute strategy
   ansible.builtin.include_tasks:
diff --git a/tasks/strategy_lineinfile.yml b/tasks/strategy_lineinfile.yml
index 7656602..2b2d02a 100644
--- a/tasks/strategy_lineinfile.yml
+++ b/tasks/strategy_lineinfile.yml
@@ -1,13 +1,23 @@
 ---
+- name: Check target file for removal
+  ansible.builtin.stat:
+    path: "{{ _target_path }}"
+  delegate_to: "{{ prometheus_target_host }}"
+  become: true
+  register: _target_file
+  when: _target_state == "absent"
+
 - name: Deploy target via lineinfile
   ansible.builtin.lineinfile:
     path: "{{ _target_path }}"
     line: "{{ prometheus_target_strategy_lineinfile_prefix ~ _target_host ~ prometheus_target_strategy_lineinfile_suffix }}"
-    state: present
+    state: "{{ _target_state }}"
   delegate_to: "{{ prometheus_target_host }}"
   become: true
   register: _lineinfile_result
+  when: _target_state == "present" or _target_file.stat.exists
 
 - name: Track changes
   ansible.builtin.set_fact:
-    changed: "{{ changed | default(false) or _lineinfile_result.changed }}"
+    changed: >-
+      {{ changed | default(false) or (_lineinfile_result.changed | default(false)) }}
diff --git a/tasks/strategy_yaml.yml b/tasks/strategy_yaml.yml
index 24cd6c8..45b18c3 100644
--- a/tasks/strategy_yaml.yml
+++ b/tasks/strategy_yaml.yml
@@ -14,10 +14,22 @@
             ((exporter.path if exporter.path is defined else defaults.path) | mandatory) -%}
         {%- set host = (exporter.host if exporter.host is defined else defaults.host) | mandatory -%}
         {%- set labels = (defaults.labels | default({})) | combine(exporter.labels | default({})) -%}
-        {%- set _ = ns.updates.append({'path': path, 'host': host, 'labels': labels}) -%}
+        {%- set target_state = exporter.state if exporter.state is defined else
+            (defaults.state | default('present')) -%}
+        {%- set _ = ns.updates.append(
+            {'path': path, 'host': host, 'labels': labels, 'state': target_state}) -%}
       {%- endfor -%}
       {{ ns.updates }}
 
+- name: Validate YAML exporter states
+  ansible.builtin.assert:
+    that: _yaml_update.state in ["present", "absent"]
+    fail_msg: "Exporter state must be 'present' or 'absent', got '{{ _yaml_update.state }}'"
+  loop: "{{ _prometheus_target_yaml_updates }}"
+  loop_control:
+    loop_var: _yaml_update
+    label: "{{ _yaml_update.path }}"
+
 # Every play host prepares its values above. Applying all updates from one host
 # prevents parallel Ansible forks from overwriting each other's YAML changes.
 - name: Aggregate YAML exporter updates
@@ -56,14 +68,27 @@
     _prometheus_target_yaml_files: >-
       {%- set output = namespace(files=[]) -%}
       {%- for file in _yaml_target_files.results -%}
+        {%- set file_updates = _prometheus_target_yaml_updates_all |
+            selectattr('path', 'equalto', file._yaml_path) | list -%}
+        {%- set present_updates = file_updates |
+            selectattr('state', 'equalto', 'present') | list -%}
         {%- set state = namespace(groups=(file.content | b64decode | from_yaml)
             if file.content is defined else []) -%}
         {%- set state.groups = state.groups if state.groups is not none else [] -%}
-        {%- for update in _prometheus_target_yaml_updates_all if update.path == file._yaml_path -%}
+        {%- for update in file_updates -%}
           {%- set next = namespace(found=false, groups=[]) -%}
           {%- for group in state.groups -%}
             {%- set group_labels = group.labels | default({}) -%}
-            {%- if group_labels == update.labels -%}
+            {%- if update.state == 'absent' -%}
+              {%- set filtered = group.targets | reject('equalto', update.host) | list -%}
+              {%- if filtered | length > 0 -%}
+                {%- set replacement = {'targets': filtered} -%}
+                {%- if group_labels | length > 0 -%}
+                  {%- set _ = replacement.update({'labels': group_labels}) -%}
+                {%- endif -%}
+                {%- set _ = next.groups.append(replacement) -%}
+              {%- endif -%}
+            {%- elif group_labels == update.labels -%}
               {%- if update.host not in group.targets -%}
                 {%- set _ = group.targets.append(update.host) -%}
               {%- endif -%}
@@ -80,7 +105,7 @@
               {%- endif -%}
             {%- endif -%}
           {%- endfor -%}
-          {%- if not next.found -%}
+          {%- if update.state == 'present' and not next.found -%}
             {%- set new_group = {'targets': [update.host]} -%}
             {%- if update.labels | length > 0 -%}
               {%- set _ = new_group.update({'labels': update.labels}) -%}
@@ -89,7 +114,9 @@
           {%- endif -%}
           {%- set state.groups = next.groups -%}
         {%- endfor -%}
-        {%- set _ = output.files.append({'path': file._yaml_path, 'groups': state.groups}) -%}
+        {%- if file.content is defined or present_updates | length > 0 -%}
+          {%- set _ = output.files.append({'path': file._yaml_path, 'groups': state.groups}) -%}
+        {%- endif -%}
       {%- endfor -%}
       {{ output.files }}
   run_once: true