Move "Customizing NGINX" documentation under "NGINX Configuration"

docs/user-guide/log-format.md

@@ -1,34 +0,0 @@
-# Log format
-
-The default configuration uses a custom logging format to add additional information about upstreams, response time and status
-
-```
-    log_format upstreaminfo '{{ if $cfg.useProxyProtocol }}$proxy_protocol_addr{{ else }}$remote_addr{{ end }} - '
-        '[$the_real_ip] - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" '
-        '$request_length $request_time [$proxy_upstream_name] $upstream_addr $upstream_response_length $upstream_response_time $upstream_status';
-```
-
-Sources:
-
-- [upstream variables](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#variables)
-- [embedded variables](http://nginx.org/en/docs/http/ngx_http_core_module.html#variables)
-
-Description:
-
-- `$proxy_protocol_addr`: if PROXY protocol is enabled
-- `$remote_addr`: if PROXY protocol is disabled (default)
-- `$the_real_ip`: 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>`
-- `$upstream_addr`: keeps the IP address and port, or the path to the UNIX-domain socket of the upstream server. If several servers were contacted during request processing, their addresses are separated by commas
-- `$upstream_response_length`: keeps the length of the response obtained from the upstream server
-- `$upstream_response_time`: keeps time spent on receiving the response from the upstream server; the time is kept in seconds with millisecond resolution
-- `$upstream_status`: keeps status code of the response obtained from the upstream server