#! /usr/bin/perl

# dh_apache2 - Apache2 configuration elper for debhelper
# Copyright (C) 2012 Arno Töll <debian@toell.net>
#
# This program is licensed at your choice under the terms of the GNU General
# Public License vserion 2+ or under the terms of the Apache Software License
# 2.0.
#
# For GPL-2+:
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# For ASF 2.0:
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

use strict;
use File::Find;
use Debian::Debhelper::Dh_Lib;


=head1 NAME

dh_apache2 - register configuration snippets to the Apache web server

=cut

# auto-generated do not edit
our $API = "__API__";
our $OPENSSL = "__OPENSSL__";
our $MODULE_DIR = "__MODULE_DIR__";
our $SERVER_VERSION = "__SERVER_VERSION__";

sub apache_api_version
{
	return "apache2-api-$API";
}

sub apache_api_ssl_version
{
	return "apache2-api-$API-$OPENSSL";
}

sub apache_depends
{
	# TODO XXX this should be determined from ap_mmn.h, too.
	my $ret = apache_api_version() . ", apache2-bin ( >= 2.4.16 )";
	if (have_apache2_ssl_dev()) {
		$ret .= ", " . apache_api_ssl_version();
	}
	return $ret;
}

sub apache_version
{
	return ">= $SERVER_VERSION~";
}

sub apache_api_installdir
{
	return $MODULE_DIR;
}

sub apache_conf_installdir
{
	my $type = shift;
	return "etc/apache2/${type}-available/"
}

sub have_apache2_ssl_dev
{
	open(my $fd, "<", "debian/control") or die "Cannot open debian/control: $!";
	my $line;
	my $builddeps = "";
	while (defined ($line = <$fd>)) {
		chomp $line;
		if ($line =~ m{^Build-Depends:}i) {
			$builddeps .= $line;
		} elsif ($builddeps) {
			if ($line =~ m{^\s}) {
				$builddeps .= $line;
			} else {
				last;
			}
		}
	}
	if ($builddeps =~ m{\bapache2-ssl-dev\b}) {
		return 1;
	} else {
		return;
	}
}

=head1 SYNOPSIS

B<dh_apache2> [S<I<debhelper options>>] [S<B<--conditional>>=I<expression>] [B<--error-handler=>I<function>] [B<-n>|B<--noscripts>]
    [B<-e>|B<--noenable>] [B<-r>|B<--restart>]

=head1 DESCRIPTION

B<dh_apache2> is a debhelper program that is responsible for correctly installing
Apache2 configuration snippets and setting postinst, prerm and dependencies in
Apache2 web server modules and web applications.

It supports the following configuration types

=over 4

=item *
Apache2 modules

=item *
Apache2 configuration snippets for web applications

=item *
Apache2 sites

=back

B<dh_apache2> supports two modes: A limited auto-configuration heuristic or
alternatively a configuration file driven approach. If a file named
debian/package.apache2 exists, actual actions are determined by that file.

=head1 OPERATION MODES

B<dh_apache2> can be used in two modes: A configuration file driven approach and
a heuristic approach. The configuration driven mode is fully documented in the
B<FILES> section below. This mode is activated by supplying a L<debhelper(7)>
configuration file (e.g. debian/I<package>.apache2).

The alternative is a heuristic mode, in which no files are installed through
B<dh_apache2>. Instead the helper will scan the package installation directory
for recognized files and guess their purpose depending on their installation
path in the file system. Use with caution.

=head1 INVOCATION

B<dh_apache2> is not part of debhelper and might require information available
in the apache2-dev package. Packages making use of B<dh_apache2> should declare
a build-dependency against the virtual B<dh-apache2> package.

B<dh_apache2> supports both, called directly from a debian/rules file or as
L<dh(1)> addon. In the former case the helper should run after L<dh_install(1)>
or their respective counter parts in local implementations at earliest.
Alternatively it can be used as L<dh> addon by invoking it with

  %:
     dh $@ --with apache2

=head1 FILES

=over 4

=item debian/I<package>.apache2

=item debian/apache2

=back

Lists files to be registered with the Apache 2 HTTP server. The file is
interpreted as line separated list of installation stanzas, where each entry
consists of whitespace separated values conforming to the file semantics below.

=head2 FILE SEMANTICS

Each line consists of a triple

I<type> I<file> [I<arguments>]

where the values are interpreted as follows:


=head3 I<type>

Denotes the type of file to be installed. Recognized values are B<conf>
for Apache2 global configuration snippets, B<site> for virtual host
configurations and B<mod> for Apache2 modules.

=head3 I<file>

Is interpreted as existing file name within the source package. No path
expansion is effectuated. Just like L<dh_install(1)>, B<dh_apache2> can not
rename files.

=head3 I<arguments>

Is inrerpreted as optional arguments if any, currently used by B<conf>
stanzas only

=head2 GLOBAL CONFIGURATION FILES

Global configuration files (determined by the B<conf> type) must have a I<.conf>
suffix and are installed to I</etc/apache2/conf-available>. Moreover, the
configuration is activated in the maintainer script at installation time.

Such global configuration snippets are supposed to be used by web applications.
Such stanzas accept an optional third I<arguments> which is interpreted as
dependency line of alternative web servers the package supports. See I<EXAMPLES>
below.

B<dh_apache2> will set dependencies in B<${misc:Recommends}> accordingly when
this type of configuration is found. Alternatives from the optional I<argument>
is incorporated into this dependency line.

=head2 SITE CONFIGURATION FILES

Site configuration files (determined by the B<site> type) must have a I<.conf>
suffix and are installed to I</etc/apache2/sites-available>. Moreover, the
configuration is activated in the maintainer script at installation time.

Such global configuration snippets are supposed to be used by web applications
and third party packages which install virtual host configurations. This type of
configuration sets the same dependencies as configuration files.

=head2 MODULES

Modules are handled specially and are determined by the B<mod> type. Modules can
either have a I<.conf> or I<.load> suffix. In that case the file is interpreted
as module load file or module configuration file respectively and is nstalled to
I</etc/apache2/mods-available>. If the file is ending with a I<.so> suffix it is
interpreted as actual module shared object and is installed to the Apache module
directory. Moreover, if a I<.load> file is installed the configuration is
activated in the maintainer script at installation time.

A typical module configuration has two lines, one for the I<.load> file, and one
for the I<.so> file, albeit the latter could be installed by upstream's
makefile, too.

B<dh_apache2> will set dependencies in B<${misc:Depends}> accordingly when
this type of configuration is found.

=head1 OPTIONS

=over 4

=item B<--error-handler=>I<function>

Call the named shell I<function> if running the maintainer script fails. The
function should be provided in the F<prerm> and F<postinst> scripts, before the
B<#DEBHELPER#> token.

=item S<B<--conditional>>=I<function>

Only execute maintainer scripts if the named shell I<function> evaluates to a
true value at installation time. This is useful to web applications which want
to install Apache configuration files depending on a user input, for example if
they interface to the user through L<debconf(1)>.

The defaults is to always execute the scripts. The named function should be
provided in the F<prerm>, F<postrm> and F<postinst> scripts, before the
B<#DEBHELPER#> token.

=item S<B<--restart>> S<B<-r>>

In maintainer scripts, do not try to reload the web server, but restart it.
Otherwise the default action is used, which means global configuration and
sites make the web server to be reloaded on success, modules are restarted.

=item B<-e>, B<--noenable>

Install maintainer scripts accordingly, but do not enable the scripts or
configuration by default.

=item B<-n>, B<--noscripts>

Do not modify F<postinst>/F<postrm>/F<prerm> maintainer scripts.


=back

=head1 NOTES

Note that this command is not idempotent. L<dh_prep(1)> should be called
between invocations of this command. Otherwise, it may cause multiple
instances of the same text to be added to maintainer scripts.

=head1 EXAMPLES

The examples below lists valid entries for a debian/I<package>.apache2 file. For
example, the two lines below install a fictional I<mod_foo> Apache module along
a Debian specific I<.load> file:

 mod src/foo/mod_foo.so
 mod debian/foo.load

The example below installs a fictional web application called phpmyfoo supplied
in a package which also supports Lighttpd and nginx:

 conf debian/phpmyfoo.conf lighttpd (>= 1.4.30) | nginx-full

Or, the same example again this time without support for other web servers:

 conf debian/phpmyfoo.conf

As a final example, install a module called I<mod_foo> along with a site
configuration for a fictional site configuration for the site I<example.com>:

 mod  src/foo/mod_foo.so
 mod  debian/foo.load
 mod  debian/foo.conf
 site debian/example_com.conf

=head1 SEE ALSO

L<apache2ctl>(8), L<a2query>(8), L<debhelper>(7), L<dh>(1)

=head1 AUTHOR

This manual and L<dh_apache2> was written by Arno Toell <debian@toell.net>.

=cut


##
## main code starts here
##

init(options => {
	"conditional=s" => \$dh{CONDITIONAL},
	"r|restart" => \$dh{RESTART},
	"e|noenable" => \$dh{NOENABLE},
});

if (!$dh{CONDITIONAL})
{
	$dh{CONDITIONAL} = 'true';
}
elsif ($dh{CONDITIONAL} !~ /^\w+$/) {
	die "The conditional function name must only contain ASCII letters, numbers, and underscores\n";
}

if ($dh{RESTART})
{
	$dh{RESTART} = 'restart';
}
else
{
	$dh{RESTART} = '';
}

foreach my $package ((@{$dh{DOPACKAGES}}))
{
	my %PACKAGE_TYPE = (
		has_a_module => [],
		has_a_conf_file => [],
		has_a_site_conf => [],
		dependency_line => "",
		handler => $dh{ERROR_HANDLER},
		conditional => $dh{CONDITIONAL}
	);

	my $file = pkgfile($package, "apache2");
	my $tmp  = tmpdir($package);

	my @files_to_register = filedoublearray($file, ".") if $file;
	foreach my $line (@files_to_register)
	{
		my $type = lc(shift @{$line}) if $line->[0];
		my $source = shift @{$line} if $line->[0];
		my @arguments = map {"$_ "} @{$line};

		$type .= "s" unless $type eq "conf";
		my $installdir = $tmp . "/" . apache_conf_installdir($type);

		#verbose_print("$type -- $source -- @arguments\n\n");

		if ($type eq "mods" or $type eq "sites" or $type eq "conf")
		{
			my $basesource = basename($source);

			if ($type eq "mods")
			{
				if ($basesource =~ m/\.load$/)
				{
					my $enablename = $basesource;
					$enablename =~ s/\.load$//;
					push @{$PACKAGE_TYPE{'has_a_module'}}, $enablename;
					verbose_print("Installing module configuration $enablename into $installdir\n");
				}
				elsif ($basesource =~ m/\.so$/)
				{
					my $modinstalldir = $tmp . "/" . apache_api_installdir();
					verbose_print("Installing module binary $source into $modinstalldir\n");
					if (! -d $modinstalldir)
					{
						complex_doit("mkdir","-p", $modinstalldir);
						complex_doit("chmod","755","$modinstalldir");
					}
					complex_doit("cp", $source, $modinstalldir);
					next;
				}

				error("module: \"$basesource\" needs .conf, .so or .load suffix") if $basesource !~ m/\.(conf|load|so)/;
			}
			elsif ($type eq "sites")
			{
				push @{$PACKAGE_TYPE{'has_a_site_conf'}}, $basesource;
				verbose_print("Installing site configuration $basesource into $installdir\n");
			}
			elsif($type eq "conf")
			{

				if ($#arguments >= 0)
				{
					$PACKAGE_TYPE{'dependency_line'} .= " | " . join("", @arguments);
				}

				if ($basesource =~ m/\.conf/)
				{
					my $enablename = $basesource;
					$enablename =~ s/\.conf$//;
					push
					@{$PACKAGE_TYPE{'has_a_conf_file'}}, $enablename;
					verbose_print("Installing global configuration $enablename into $installdir\n");
				}
				error("configuration file: \"$basesource\" needs .conf suffix") if $basesource !~ m/\.conf/;
			}

			if (! -d $installdir)
			{
				complex_doit("mkdir","-p",$installdir);
				complex_doit("chmod","755","$installdir");
			}
			complex_doit("cp",$source,$installdir);
			complex_doit("chmod","644","$installdir/$basesource");

		}
		else
		{
			error("Unknown parameter: $type\n");
		}

	}


	if (! $file)
	{
		# do black magic only if there is no .apache2 configuration file
		find({  no_chdir => 1,
			wanted => sub
			{
				my ($dir, $file) = (dirname($File::Find::name), basename($File::Find::name));
				# remove extension
				my $conf_name = $file;
				$conf_name =~ s/\.[^.]+$//;

				if ($dir =~ m#etc/apache2/mods-available# and $file =~ m#.(load|conf)$#)
				{
					verbose_print("package $package appears	to be a web server module\n");
					push @{$PACKAGE_TYPE{'has_a_module'}}, $conf_name if $file =~ m/\.load/;
				}
				if ($dir =~ m#etc/apache2/sites-available# and $file =~ m#.conf$#)
				{
					verbose_print("package $package appears	to contain a virtual host configuration\n");
					push @{$PACKAGE_TYPE{'has_a_site_conf'}}, $conf_name;
				}
				if ($dir =~ m#etc/apache2/conf-available# and $file =~ m#.conf$#)
				{
					verbose_print("package $package appears	to contain a global configuration file \n");
					push @{$PACKAGE_TYPE{'has_a_conf_file'}}, $conf_name;
				}



		}}, tmpdir($package));
	}


	my @postinst_autoscripts;

	if ($#{$PACKAGE_TYPE{'has_a_module'}} >= 0)
	{
		if ($package !~ m/libapache2-mod-\w+?/)
		{
			warning("Package $package appears to be an Apache module. It should comply to the package naming scheme libapache2-mod-<modulename>\n");
		}
		addsubstvar($package, "misc:Depends", apache_depends());

		my $modules = "";
		foreach my $module (@{$PACKAGE_TYPE{'has_a_module'}})
		{
			$modules .= "$module ";
		}

		push @postinst_autoscripts, ["enmod", $modules];
	}

	if ($#{$PACKAGE_TYPE{'has_a_conf_file'}} >= 0 or $#{$PACKAGE_TYPE{'has_a_site_conf'}} >= 0)
	{
		$PACKAGE_TYPE{'dependency_line'} .= "| httpd";
		addsubstvar($package, "misc:Recommends", "apache2 ( >= 2.4.6-4~ ) " . $PACKAGE_TYPE{'dependency_line'} );

		my $confs = "";
		my $sites = "";

		foreach my $conf (@{$PACKAGE_TYPE{'has_a_conf_file'}})
		{
			$confs .= "$conf ";
		}

		foreach my $site (@{$PACKAGE_TYPE{'has_a_site_conf'}})
		{
			$sites .= "$site ";
		}

		if ($confs)
		{
			push @postinst_autoscripts, ["enconf", $confs];
		}
		if ($sites)
		{
			push @postinst_autoscripts, ["ensite", $sites];
		}

	}

	if (! $dh{NOSCRIPTS})
	{
		foreach my $ref (@postinst_autoscripts)
		{
			for my $script_type (qw/postinst prerm postrm/)
			{
				if ($script_type eq "postinst" &&  $dh{NOENABLE})
				{
					next
				}

				my %replacements = (
					HELPER => $ref->[0],
					NAMES  => $ref->[1],
					ERROR_HANDLER => $PACKAGE_TYPE{handler},
					CONDITIONAL_VARIABLE => $PACKAGE_TYPE{conditional},
					ACTION => $dh{RESTART},
				);

				if ($script_type eq "prerm" || $script_type eq "postrm")
				{
					$replacements{'HELPER'} =~ s/en/dis/;
				}

				my $sed_command = "";
				foreach my $key (sort keys %replacements)
				{
					my $val = $replacements{$key};
					# Use a control char as separator for sed, to
					# reduce escaping issues. Everything else is
					# passed verbatim, i.e. it must not contain any
					# shell or sed special characters.
					my $sep = "\x17";
					$sed_command .= "s" . $sep . "#$key#" .
							      $sep . $val .
							      $sep . "g; ";
				}

				autoscript($package, "$script_type", "$script_type-apache2", $sed_command);
			}
		}
	}
}
