Building From Source
====================

In general, this is a standard autoconf-style project:
./configure && make check && sudo make install

If your starting point is a tarball, the following prerequisites apply:

* A basically functional POSIX build environment with a C99 compiler
* libev headers and libraries, version 4.x: distro pkg
  or http://software.schmorp.de/pkg/libev.html
* Ragel 6.x: http://www.complang.org/ragel/ (or distro package)
* Perl 5.10.1 or higher and the perl "pod2man" command for document
  generation (this may be in the package perl-podlaters)

The following are recommended but optional:

* liburcu aka userspace-rcu headers and libraries. Use distro pkg or
  http://lttng.org/urcu/ (important for performance!)
* libmaxminddb headers and libraries to enable MaxMind GeoIP2 database
  support: https://github.com/maxmind/libmaxminddb/releases
  Preferably version 1.2.0 or higher!
* libunwind headers and libraries. (for stacktrace on some fatals)

The following have no real effect on the build or runtime, but are
required in order to run the testsuite:

* Perl modules: JSON::PP, LWP 5.805+, Socket6, IO::Socket::INET6, HTTP::Daemon
  (JSON::PP comes with Perl v5.13.9 and higher)

If working directly from a git clone:

* autoconf (2.63+), automake(1.11.1+), and libtool(2.2.6+) packages
* If you want "make check" to run optional GeoIP-related unit tests which use
  large compressed files, those are stored in a separate repo as a submodule.
  You can bring them into your tree via: "git submodule update --init".
  You will also need the 'xz' compression utility installed to unpack them.
* Start with "autoreconf -vif", then ./configure ...

Interesting / Non-standard autoconf options
===========================================

--with-rundir=/some/where
  Set an alternate system-level rundir, e.g. in situations where a Linux
    distro wants to use "/run" in place of "/var/run".

--with-systemdsystemunitdir=DIR
  Sets the install path for the systemd gdnsd.service unit file on
    linux hosts with systemd, which would normally be obtained via:
    "pkg-config --variable=systemdsystemunitdir systemd".
  Note that the automatic value for this from pkg-config doesn't follow
    autoconf's prefix at all; it will still pick e.g.
    "/usr/lib/systemd/system" even when --prefix is "/usr/local".
  If pkg-config and/or systemd do not exist and this is not set manually
    the unit file is generated, but not installed.
  To disable the installation of the unit file on systems which have
    systemd software installed (but e.g. are not using it for the init
    system), use --without-systemdsystemunitdir

--without-urcu
  Explicitly disable support for liburcu (falls back to pthread rwlocks)

--without-hardening
  Disable the default compiler/linker flags for security hardening.
  Probably not a great idea unless they're breaking things on your
    platform and/or you're supplying replacement flags of your own.

--enable-developer
  Builds a debugging build (-g) with a large suite of assert()ions, extra
    informative debug information via STDERR or syslog(), and some
    other expensive, excessive runtime checks that really slow things down.
  Not generally for production use, but handy for development or tracking
    down evasive bugs.  If you just want debug symbols, put -g in CFLAGS.

--with-testport=N
  The test suite needs to be able to bind to ~300 consecutive ports on
    127.0.0.1 and ::1, starting with port N.  The default is 12345.  If this
    conflicts with some existing service on your machine, change it here.
