r/vmalert: Deploy vmalert

`vmalert` is a component of Victoria Metrics. It handles alerting and
recording rules, periodically executing queries and dispatching alerts
or writing aggregated data back to the TSDB.

roles/vmalert/tasks/deploy.yml

@@ -0,0 +1,59 @@
+- name: ensure victoria metrics config directory exists
+  file:
+    path: /etc/victoria-metrics
+    mode: u=rwx,go=rx
+    owner: root
+    group: root
+    state: directory
+  tags:
+  - config
+- name: ensure vmalert rules directory exists
+  file:
+    path: /etc/victoria-metrics/rules
+    mode: u=rwx,go=rx
+    owner: root
+    group: root
+    state: directory
+  tags:
+  - config
+
+- name: ensure vmalert alert rules are configured
+  copy:
+    dest: /etc/victoria-metrics/rules/alerts.yml
+    content: |+
+      {{ vmalert_rules | to_nice_yaml(indent=2) }}
+    mode: u=rw,go=r
+    owner: root
+    group: root
+  notify:
+  - reload vmalert
+  tags:
+  - config
+  - alerts-config
+
+- name: ensure vmalert environment variables are set
+  template:
+    src: vmalert.sysconfig.j2
+    dest: /etc/sysconfig/vmalert
+    mode: u=rw,go=r
+    owner: root
+    group: root
+  notify:
+  - restart vmalert
+  tags:
+  - config
+
+- name: ensure vmalert starts at boot
+  service:
+    name: vmalert
+    enabled: true
+  tags:
+  - service
+- name: flush handlers
+  meta: flush_handlers
+- name: ensure vmalert is running
+  service:
+    name: vmalert
+    state: started
+  tags:
+  - service