coredns/placeholder.md

# Placeholders

Some directives allow you to use placeholders in your Caddyfile to fill out a value differently for every request. For example, the value {path} would be replaced by the path portion of the request URL. These are also called replaceable values.
These placeholders only work on directives that support them. Check the documentation for your directive to see if placeholders are supported.
Request Placeholders

These values are obtained from the request.

* {dir} - The directory of the requested file (from request URI)
* { file} - The name of the requested file (from request URI)
* {fragment} - The last part of the URL starting with "#"
* {>Header} - Any request header, where "Header" is the header field name
* {host} - The host portion of the request
* {method} - The request method (GET, POST, etc.)
* {path} - The path portion of the URL (does not include query string or fragment)
* {port} - The client's port
* {proto} - The protocol string (e.g. "HTTP/1.1")
* {query} - The query string portion of the URL, without leading "?"
* {remote} - The client's IP address
* {scheme} - The protocol/scheme used (usually http or https)
* {uri} - The request URI (includes path, query string, and fragment)
* {when} - Timestamp in the format 02/Jan/2006:15:04:05 -0700

## Response Placeholders

These values are obtained from the response, and are only implemented with some directives. Make sure your directive supports response placeholders before attempting to use them.

* {latency} - Approximate time the server spent handling the request
* {size} - The size of the response body
* {status} - The HTTP status code of the response