The purpose of this module is to provide a dynamic director similar to the DNS director from Varnish 3. It also was previously known as vmod-named. This is not a drop-in replacement for the DNS director, because in Varnish 3 the director had two modes of execution that aren't compatible with changes in the backend and director subsystems introduced by Varnish 4.0.
Instead a dynamic director relies on dynamic backends, supports white-listing and even probes. However, just like the DNS director from Varnish 3 it has limited capabilities because it relies on the system's resolver. It builds against Varnish 4.1.2 and later versions.
Further documentation is available in the manual page vmod_dynamic(3).
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.
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 instance, when varnishd configure was called
with --prefix=$PREFIX, use
export PKG_CONFIG_PATH=${PREFIX}/lib/pkgconfig
export ACLOCAL_PATH=${PREFIX}/share/aclocal
The module will inherit its prefix from Varnish, unless you specify a
different --prefix when running the configure script for this
module.
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.
If you build a dist tarball, you don't need any of the autotools, only pkg-config and Varnish. You can build the module simply by running:
./configure make
For the test suite to work, please add this line to your /etc/hosts:
127.0.0.1 www.localhost img.localhost
then run:
make check
Alternatively, the make check can also be skipped.
You can then proceed with the installation:
sudo make install
By default, the vmod configure script installs the built vmod in the
directory relevant to the prefix. The vmod installation directory can be
overridden by passing the vmoddir variable to make install.
Instead of directly installing the package you can build an RPM:
make dist rpmbuild -tb *.tar.gz
If you need to build an RPM for a different platform you may use mock(1):
make dist mock --buildsrpm --resultdir . --sources . --spec vmod-querystring.spec mock --rebuild --resultdir . *.src.rpm
If you want to learn more about DNS, you can start with RFC 1034 and other RFCs that updated it over time. You may also have DNS already in place, or may be interested in setting up a name server in your infrastructure. Below is a non-exhaustive list of tools and services, but for free software name servers you can have a look at debianadmin.
DNS in the cloud (in alphabetic order):
DNS and containers (in alphabetic order):
- DC/OS (Mesos)
- Docker Machine (sort of)
- Kubernetes