vmod_sleep

Varnish Sleep Module

Date:	2016-07-14
Version:	1.0
Manual section:	3

SYNOPSIS

import sleep;

DESCRIPTION

Sleep in VCL.

FUNCTIONS

sleep

Prototype

sleep(DURATION t)

Return value

VOID

Description

Sleeps for specified amount of time (t). Supported types are ms (milliseconds), s (seconds), m (minutes), h (hours), d (days), w (weeks) and y (years). NOTE, please be aware of the various timeouts which may trigger if you sleep too long.

Example

sleep.sleep(1ms);

USAGE EXAMPLE

In your VCL you could then use this vmod along the following lines:

import sleep;

sub vcl_backend_error {
        sleep.sleep(5s);
        return (retry);
}

INSTALLATION

The source tree is based on autotools to configure the building, and does also have the necessary bits in place to do functional unit tests using the varnishtest tool.

Building requires the Varnish header files and uses pkg-config to find the necessary paths.

Pre-requisites:

sudo apt-get install -y autotools-dev make automake libtool pkg-config libvarnishapi1 libvarnishapi-dev

Usage:

./autogen.sh
./configure

If you have installed Varnish to a non-standard directory, call autogen.sh and configure with PKG_CONFIG_PATH pointing to the appropriate path. For sleep, when varnishd configure was called with --prefix=$PREFIX, use

PKG_CONFIG_PATH=${PREFIX}/lib/pkgconfig export PKG_CONFIG_PATH

Make targets:

make - builds the vmod.
make install - installs your vmod.
make check - runs the unit tests in src/tests/*.vtc
make distcheck - run check and prepare a tarball of the vmod.

Installation directories

By default, the vmod configure script installs the built vmod in the same directory as Varnish, determined via pkg-config(1). The vmod installation directory can be overridden by passing the VMOD_DIR variable to configure.

Other files like man-pages and documentation are installed in the locations determined by configure, which inherits its default --prefix setting from Varnish.

COMMON PROBLEMS

configure: error: Need varnish.m4 -- see README.rst

Check if PKG_CONFIG_PATH has been set correctly before calling autogen.sh and configure
Incompatibilities with different Varnish Cache versions

Make sure you build this vmod against its correspondent Varnish Cache version. For sleep, to build against Varnish Cache 4.0, this vmod must be built from branch 4.0.

rezan/libvmod-sleep