Create promtail-examples.md

simple configs and description

docs/promtail-examples.md

+# promtail examples
+#### In this file you can see simple examples of configure promtail
+
+For work with 2 and more sources:
+```
+server:
+  http_listen_port: 9080
+  grpc_listen_port: 0
+
+positions:
+  filename: /tmp/positions.yaml
+
+client:
+  url: http://ip_or_hostname_where_Loki_run:3100/api/prom/push
+
+scrape_configs:
+ - job_name: system
+   entry_parser: raw
+   static_configs:
+   - targets:
+      - localhost
+     labels:
+      job: varlogs
+      host: yourhost
+      __path__: /var/log/*.log
+
+ - job_name: someone_service
+   entry_parser: raw
+   static_configs:
+   - targets:
+      - localhost
+     labels:
+      job: someone_service
+      host: yourhost
+      __path__: /srv/log/someone_service/*.log
+
+```
+#### Description
+Scrape_config section of config.yaml contents are various jobs for parsing your logs on current host
+
+`job` and `host` these are tags on which you can filter parsed logs date on Grafana later
+
+`__path__` it is path to directory where stored your logs. (*)
+
+* - If you run promtail and this config.yaml in Docker container, you can use docker volumes for mapping real directories
+with log to those folders in the container.