add promtail role

roles/promtail/templates/promtail.service.j2

@@ -0,0 +1,19 @@
+{{ ansible_managed | comment }}
+
+[Unit]
+Description=Loki
+After=network-online.target
+
+[Service]
+Type=simple
+User={{ promtail_user }}
+Group={{ promtail_group }}
+ExecStart={{ promtail_bin_path }}/promtail \
+  -config.file {{ promtail_config_path }}
+WorkingDirectory={{ promtail_var_path }}
+
+Restart=always
+RestartSec=1
+
+[Install]
+WantedBy=multi-user.target

roles/promtail/templates/promtail.yaml.j2

@@ -0,0 +1,21 @@
+{{ ansible_managed | comment }}
+---
+{% if promtail_server is defined %}
+server:
+  {{ promtail_server | to_nice_yaml(indent=2) | indent(2, False) }}
+{% endif -%}
+
+{% if promtail_positions is defined %}
+positions:
+  {{ promtail_positions | to_nice_yaml(indent=2) | indent(2, False) }}
+{% endif -%}
+
+{% if promtail_clients is defined %}
+clients:
+  {{ promtail_clients | to_nice_yaml(indent=2) | indent(2, False) }}
+{% endif -%}
+
+{% if promtail_scrape_configs is defined %}
+scrape_configs:
+  {{ promtail_scrape_configs | to_nice_yaml(indent=2) | indent(2, False) }}
+{% endif -%}