Log format

The default configuration uses a custom logging format to add additional information about upstreams, response time and status.

log_format upstreaminfo
    '$remote_addr - $remote_user [$time_local] "$request" '
    '$status $body_bytes_sent "$http_referer" "$http_user_agent" '
    '$request_length $request_time [$proxy_upstream_name] [$proxy_alternative_upstream_name] $upstream_addr '
    '$upstream_response_length $upstream_response_time $upstream_status $req_id';

Placeholder	Description
`$proxy_protocol_addr`	remote address if proxy protocol is enabled
`$remote_addr`	the source IP address of the client
`$remote_user`	user name supplied with the Basic authentication
`$time_local`	local time in the Common Log Format
`$request`	full original request line
`$status`	response status
`$body_bytes_sent`	number of bytes sent to a client, not counting the response header
`$http_referer`	value of the Referer header
`$http_user_agent`	value of User-Agent header
`$request_length`	request length (including request line, header, and request body)
`$request_time`	time elapsed since the first bytes were read from the client
`$proxy_upstream_name`	name of the upstream. The format is `upstream-<namespace>-<service name>-<service port>`
`$proxy_alternative_upstream_name`	name of the alternative upstream. The format is `upstream-<namespace>-<service name>-<service port>`
`$upstream_addr`	the IP address and port (or the path to the domain socket) of the upstream server. If several servers were contacted during request processing, their addresses are separated by commas.
`$upstream_response_length`	the length of the response obtained from the upstream server
`$upstream_response_time`	time spent on receiving the response from the upstream server as seconds with millisecond resolution
`$upstream_status`	status code of the response obtained from the upstream server
`$req_id`	value of the `X-Request-ID` HTTP header. If the header is not set, a randomly generated ID.

Additional available variables:

Placeholder	Description
`$namespace`	namespace of the ingress
`$ingress_name`	name of the ingress
`$service_name`	name of the service
`$service_port`	port of the service

Sources: