Special backends are backends that don’t rely on an external server
to handle the response, but instead are served by pound
itself.
Return a particular HTTP status.
The status argument supplies the HTTP status code to return.
Optional file argument is the name of a disk file with the error
page content. If not supplied, the text is determined as usual: first
the ErrorFile status statement from the enclosing listener is
consulted. If it is not present, the default error page is used.
This directive is useful in a catch-all service, which outputs an error page if no service matching the incoming request was found. See Error responses, for a discussion.
Declares a special backend that responds to each request with a redirect response.
Optional code can be one of: 301, 302 (the default), 303, 307, or 308.
The url argument specifies the URL to redirect the request to. Before use it is expanded as described in String Expansions.
For compatibility with previous pound versions, if no
‘$n’ references are found in url, the following logic
is used: if it is a "pure" host (i.e. with no path) then the client will be
redirected to that host, with the original request path appended. If
the url does contain a path (even if it is just a ‘/’),
then the request path is ignored.
See Redirects, for a detailed discussion of this backend and its use.
Defines a special backend that serves static files from directory
dir. Name of the file to serve is supplied by the request path,
after applying usual request modifications (see Request Modification). By default, the response bears Content-Type:
text/plain header. To change this, use SetHeader statement in
response rewriting (see The Rewrite response statement.).
The following example defines a service which will serve requests to paths beginning with ‘/about/’ from directory /var/lib/pound/static. Name of the file to serve is obtained by removing the ‘/about/’ prefix from the request pathname. Content type is set to ‘text/html’:
Service
Path -re "/about/(.+)"
SetPath "$1"
Rewrite response
SetHeader "Content-Type: text/html"
End
SendFile "/var/lib/pound/static"
End
Defines a special backend that serves pound management interface. See Remote Access to Management Interface, for a detailed discussion of this feature.
This directive defines a special backend that generates Openmetric telemetry output on the given URL. Example usage:
Service
URL "/metrics"
Metrics
End
To control access to the telemetry endpoint, use the ACL
statement (see ACL).
The LogSuppress directive (see LogSuppress) is often used
in openmetric services to suppress logging of served HTTP requests:
Service
URL "/metrics"
Metrics
ACL "secure"
LogSuppress success
End
The metrics output is discussed in Metric Families.
Defines an emergency backend, which will be used only if all
other backends become unavailable. See Backend, for a discussion
of directives that can be used within Emergency section.
If multiple Emergency sections are defined, an emergency
backend to use will be selected using the usual balancing technique
(see Request balancing).