Loki format expressions for common log formats

loki-expressions.md

• Apache common log format (Pattern format)

<source> - <user> [<timestamp>] "<method> <url> <type>" <status> <bytes>

• Apache combined log format (Pattern format)

<source> - <user> [<timestamp>] "<method> <url> <type>" <status> <bytes> "<referer>" "<agent>" <requestlength> 

• Kubernets NGINX Ingress log format (RegEx format)

(?P<source>[^ ]*) - (?P<user>[^ ]*) \[(?P<timestamp>[^\]]*)\] "(?P<method>[^ ]*) (?P<url>[^ ]*) (?P<type>[^ ]*) (?P<status>[^ ]*) (?P<bytes_sent>[^ ]*) "(?P<referer>[^"]*)" "(?P<user_agent>[^"]*)" (?P<request_length>[^ ]*) (?P<request_time>[^ ]*) \[(?P<proxy_upstream_name>[^\]]*)\] \[(?P<proxy_alternative_upstream_name>[^\]]*)\] (?P<upstream_addr>[^ ]*) (?P<upstream_response_length>[^ ]*) (?P<upstream_response_time>[^ ]*) (?P<upstream_status>[^ ]*) (?P<req_id>[^ ]*)