=pod

=head1 NAME

cpantorpm - An RPM packager for perl modules

=head1 SYNOPSIS

   cpantorpm [OPTIONS] MODULE

This script takes a perl module and creates an RPM for it.

=head1 DESCRIPTION

This script automates the entire process of obtaining a perl module
and turning it into an RPM package.  This includes the steps of
obtaining the module distribution, creating an RPM from it, and then
making the package available in various ways.

The following steps are involved in this process, and are discussed
in more detail below:

=over 4

=item B<Obtain the perl module>

=item B<Parse various perl modules files for necessary information>

=item B<Build the package>

=item B<Generate a spec file>

=item B<Create the RPM packages>

=item B<Sign the RPM packages (optional)>

=item B<Install the RPM (optional)>

=item B<Store the RPM in a local yum repository (optional)>

=back

=head1 OPTIONS

=head2 General Options

The following general purpose options exist.

=over 4

=item B<-h/--help>

Prints a help message describing command usage.

=item B<-v/--version>

Prints the version of this program.

=item B<-D/--debug>

Enable verbose debugging output.

=item B<-t/--tmpdir DIR>

The cpantorpm script makes use of a default directory to store all of it's
working files in.  It defaults to:

   /tmp/cpantorpm

but can be set explicitly with this option.

=item B<-f/--optfile FILE>

All of the options below that may be specified on the command line may
also come from a config file.  The config file may contain the options
for any number of modules and is described below.

=back

=head2 Obtain the perl module Options

The following options affect how a module is downloaded.

=over 4

=item B<-c/--cpan>

When downloading modules from CPAN, the script will first try to use CPANPLUS
and, if that is not available, it will use CPAN.  If this option is included,
only CPAN will be tried.

=item B<--extracted DIR>

Occasionally, the archive file on CPAN is broken in that the archive file
(minus the relevent suffixes) is not the same as the archived directory.

For example, the archive Foo-Bar-1.00.tar.gz contains the directory
Foo-Bar instead of Foo-Bar-1.00 .

Set B<DIR> to be the name of the directory that it contains.

=back

=head2 Module Description Options

Once the module is downloaded, it will be analyzed and various information
about the module which will be used in creating the RPM is gathered.  This
includes looking at the perl META files, the main POD document, and the
build scripts (Makefile.PL or Build.PL).

The following options impact these operations:

=over 4

=item B<--name NAME>

By default, the name of the package will be obtained from the
distribution name.  This option can be used to explicitly set the
name, overriding the distribution name.

NOTE: the name of the RPM will be based on this, but will typically
have a prefix added.  See the B<--prefix> and B<--no-prefix> options below
for more details.

=item B<--summary TEXT>

Every package has a 1-line summary description.  By default, this comes
from the main POD document or the META files, but can be explicitly
set using this option.

=item B<--description FILE>

Every package has a multi-line description.  To override the description
that comes from the POD document, put the description in a local file,
and pass that file name to this option.

=item B<--mainpod FILE>

The description and summary of the module typically come from the main
POD document, if it can be determined using the normal methods described
below.

In a few cases (where the POD document is named in some non-standard
way), it may not be possible to determine which is the main POD document.
In this case, you can specify it using this option.

FILE is the path to the file relative to the top level in the module
distribution. For example, it might be:

   lib/Foo/Bar.pm

=item B<--author AUTHOR>

This lists an author for the module, overriding the values from the META
files.  This option can be included multiple times for multiple authors.

=item B<--vers VERSION>

This specifies the version of the RPM.  It defaults to the version of
the package, but can be overridden here.

=back

=head2 SPEC File Options

The following options are used during the SPEC file creation step:

=over 4

=item B<-n/--no-tests>

=item B<--NO-TESTS>

When creating a module RPM, typically, the module tests are run
as part of the process.  These two options can be used to modify
this behavior.

The first will add the lines necessary to run the tests to the
SPEC file, but (by use of an environment variable), the tests will
not be run when the RPM is created.  In this instance, if the
SPEC file is used to create an RPM at some later date, the tests
will run (unless the environment variable RPMBUILD_NOTESTS is
set).

With the second option, the lines necessary to run the tests will
not be added to the SPEC file at all.

=item B<-d/--no-deps>

=item B<--NO-DEPS>

By default, when building an RPM, the prerequisites for the module
will be tested.

There are three types of prerequisites:

   prerequisites to build the module
   prerequisites to run the module tests
   prerequisites to use the installed module

It is slightly unfortunate that RPM only recognizes two types.  There
is no way to specify requirements to run tests.

As such, the build requirements will include those requirements to
run the tests unless the --NO-TESTS option is given.  In this case,
requirements to run the tests will be omitted.

If the B<--no-deps> option is given, dependencies will not be tested
(though they will be added to the SPEC file).

If the B<--NO-DEPS> option is given, dependencies will not be added
to the SPEC file at all.

In addition, if either of these are given, B<--no-tests> is implied.

=item B<--no-compat>

By default, the SPEC file includes a line of the form:

   Requires: perl(:MODULE_COMPAT_ ...

This is recommended in the fedora packaging guidelines, so is included
by default.  Some linux distros may not have a version of perl that
provides a MODULE_COMPAT, so in these cases, you may need to omit this
from the spec.  Use this option to do so.

=item B<--prefix PREFIX>

=item B<--no-prefix>

By default, a prefix of 'perl-' is added to the name of the package
(or the name supplied using the B<--name> option).

To specify that no prefix be added, use the B<--no-prefix> option.  To
specify an alternate prefix, use the B<--prefix> option.

=item B<-p/--packager PACKAGER>

Use this option to specify the name of the packager.  The name of the
packager may be suplied using the '%packager' macro in the ~/.rpmmacros
file.  If it is not there, this option must be included.

=item B<--rpmbuild DIR>

RPMs are built in the RPM build hierarchy.  This defaults to the value
of the '%_topdir' macro, or it can be specified using this option.

If this option is used, the path must be fully specified.  A relative path
will not work.

The directory will have the following subdirectories:

   BUILD
   SOURCES
   SPECS
   SRPMS
   RPMS

=item B<--clean-macros>

By default, macros included in the existing ~/.rpmmacros file will be
used.  With this option, that file is temporarily removed (it will be
restored when the script exits).

=item B<--group GROUP>

Every package is a member of a group.  If this is not specified, it defaults
to:

   Development/Libraries

=item B<--release STRING>

=item B<--disttag STRING>

The full name of an RPM is something like:

   foo-bar-1.00-1a-noarch.rpm

The string '1a' here consists of the release (1) and a disttag (a).
By default, release is '1' and disttag is the macro '%{?dist}', but
these can be overridden with these options.

=item B<--epoch EPOCH>

This sets an epoch number in the RPM when the version number is not
sufficient to determine the relative age of two different versions.

=item B<--add-require FEATURE[=VERS]>

=item B<--add-provide FEATURE[=VERS]>

Every RPM has a list of features that are required in order to use it,
and a list of features that it provides.

In some cases, you may need to add featurs to these two lists.  Both options
may include a version:

   --add-requires Foo::Bar=0.45

=item B<--rem-require FEATURE>

=item B<--rem-provide FEATURE>

Related to the previous options, these options allow you to remove a feature
from the requirements list, or the list of features provided.

=item B<--repl-require FEATURE=VERS>

=item B<--repl-provide FEATURE=VERS>

Occasionally, the module author explicitly defines the version of a feature
that is required, or provided by this module, in a way that breaks things.

These options (which can be included any number of times) will replace the
version for either a required feature or a provided feature as they will
appear in the spec file.  That way, for example, you can make the version
of the requirement match what is provided in other RPMs.

For example, if the perl RPM that is installed on the system provides
the feature perl=5.24.1 but the module requires perl=5.008001,
rpmbuild may fail because it doesn't know how to compare these two
version numbers to know whether the requirement is met.  When this
happens, rpmbuild will fail due to missing dependencies.

In this cae, you could reformat the dependency version by passing in:

   --repl-require perl=5.08.1

=item B<-m, --macros>

Use the macro form of common SPEC constructs over the environment variable
form (e.g. %{buildroot} vs $RPM_BUILD_ROOT).

=item B<--build-rec, --test-rec, --runtime-rec>

Many modules have a list of modules that are recommended to be
installed at build time, test time, or at run time, but they are not
absolutely required.  By default, these modules will not be included
as requirements for the various steps.  Adding these options will
require them.

=back

=head2 Module Build Options

The perl module must be built as part of the process.  The following
options are used during the build:

=over 4

=item B<--build-type TYPE>

TYPE must be 'make' or 'build' and specifies that the build must be done
using the Makefile.PL or Build.PL files respectively (for those modules
that have both).  If that file does not exist, an error is triggered.

=item B<--config STRING>

The given string is passed to either the 'perl Build.PL' or 'perl
Makefile.PL' command used to configure the module and create a Build
script or a Makefile.  This option can be passed in any number of
times, but only a single option should be included in each STRING.
B<STRING> is passed in as a command line argument:

   perl Makefile.PL STRING
   perl Build.PL STRING

Since the arguments passed in differ when using a Makefile.PL and a
Build.PL procedure, for safety, you should always include the B<--build-type>
option when using this option.

=item B<--build STRING>

Similar to the B<--config> option except this passes strings which
are passed to either the './Build' or 'make' command used to actually
build the module.  This option can be passed in any number of times.

=item B<--config-input STRING>

Sometimes, the configure step prompts for input that cannot be set
using an environment variable.  In this case, this option may be used
to pass in a single line of input to the 'perl Build.PL' or 'perl
Makefile.PL' command used to configure the module and create a Build
script or a Makefile.  This option can be passed in any number of
times, but each value should include a single line of input.  This will
result in the following:

   echo STRING | perl Makefile.PL
   echo STRING | perl Build.PL

Since the arguments passed in differ when using a Makefile.PL and a
Build.PL procedure, for safety, you should always include the B<--build-type>
option when using this option.

=item B<--build-input STRING>

Similar to the B<--config-input> option except this passes strings which
are passed to either the './Build' or 'make' command used to actually
build the module.  This option can be passed in any number of times.

=item B<-T/--install-type TYPE>

=item B<-i/--install-base DIR>

These options allow you to specify where the module will be installed.
By default, the module will be built to install in the standard
perl location.  In most cases, that would mean installing the module,
documentation, and scripts in:

   BASEDIR/lib/perl5/PERLVERS
   BASEDIR/man
   BASEDIR/bin

where BASEDIR is the place where perl is installed (which is typically
/usr) and PERLVERS is the version directory (i.e. 5.14.2).  To install
in /usr/local instead of /usr, just use the option:

   --install-base /usr/local

To change the module installation directory (but not the directory of the
documentation or scripts) to either the site_perl or vendor_perl location,
use:

   --install-type site
   --install-type vendor

to set the module directory to be:

   BASEDIR/lib/perl5/site_perl/PERLVERS
   BASEDIR/lib/perl5/vendor_perl/PERLVERS

respectively.

The B<--install-type> value must be one of:

   perl  (or core)
   site
   vendor

and defaults to 'perl'.  'perl' and 'core' are synonyms.  If this is
passed in, it will override any default value set in the Makefile.PL
or Build.PL scripts (so be careful about rebuilding core modules).

=item B<--mandir STRING>

When specifying a prefix (using the B<--install-base> option), it is
necessary to determine where man pages should be installed relative
to this directory.

Most of the time, this can be determined automatically, but if your
version of perl installs man pages by default in a completely separate
location from where it installs libraries, it may not be able to be
determined correctly and should be specified using this.

The only time this would happen would be if the man pages were installed
in one hierarchy and the libraries in a completely different hierarchy
(i.e. man pages in /usr and libraries in /opt for example).

=item B<--patch FILE>

=item B<--patch-dir DIR>

=item B<--script FILE>

=item B<--script-dir DIR>

In a few cases, a distribution cannot be properly packaged unless it
is first modified.  The modification can be done by applying a patch,
or by running a script, or both.  Patches are applied first, followed
by scripts.

To specify a patch file or script file, use the B<--patch> or B<--script>
options.  Alternately, you can specify a directory containing files named
PACKAGE.sh or PACKAGE.diff where PACKAGE is the string that was passed
in on the command line.

By default, no patch or script will be used.  They will only be used
if one of these options is given.

Scripts and patches will both be applied while in the top directory
of the package (i.e. the directory where a Makefile.PL or Build.PL
script exists).

The B<--script-dir> option has a second use.  If there is a file named
PACKAGE.build-sh in it, the lines in that file are added to the SPEC
file at the end of the %build step.

=back

=head2 Options Controlling Cpantorpm Steps

To control what steps get done, the following options are available:

=over 4

=item B<--spec-only>

By default, the script creates a SPEC file, and then builds
RPMs (both source and binary).

With the B<--spec-only> option, the SPEC file is created, but no
further action is taken.

=item B<--no-clean>

By default, the build tree will be removed after the RPM is built.
If this option is given, it will be left in place.

=item B<-s/--sign>

If this option is given, a GPG signature will be added to the package.

It should be noted that this step is often interactive, so if the
installation process is scripted in any way, adding this option may
interfere with the process.

Please refer to the secrtion SIGN THE RPM PACKAGE for more information.

=item B<-I/--install>

=item B<--install-new>

=item B<--install-force>

If any of these options are given, cpantorpm will attempt to install
the RPM on the system after it is built.  If you are running as root,
this will be done by simply running the appropriate rpm command.  If
you are running as any other user, the command will be run using
B<sudo>.

By default, the '-U' flag is given to the B<rpm> command which will cause
it to install the RPM if it is a new package, or an upgrade to an existing
package.

If the B<--install-new> option is given, the '-i' option will be passed
to the B<rpm> command and the RPM will only be installable if it is a new
package.

If the B<--install-force> option is used, the flags '-U --force' will
be used which will replace an existing package, even if the same
version is already installed.

=item B<-y/--yum DIR>

If this option is given, the RPMs (both binary and source) will be
copied to a local yum repository once they are built.

=back

=head2 Misc Options

The following misc. options are also available:

=over 4

=item B<--gpg-path PATH>

=item B<--gpg-name NAME>

These options are used to set the path the the GPG directory (which
contains the keyring) and the name of the key that will be used.

=item B<--gpg-password PASSWORD>

=item B<--gpg-passfile FILE>

When signing a package, this script become interactive unless B<expect>
(or perl B<Expect>) is available.  If one of these is available, the
password can be passed in at the command line (or a file containing the
password) using one of these two commands.

=item B<--env VAR=VAL>

Sets an environment variable before building the package.  This option
can be used any number of times.

=back

=head1 OBTAIN THE PERL MODULE

The perl module may be obtained in a number of different ways.  The
perl module may exist on local disk either as an archive file or a
directory, or it can be retrieved from a URL or from CPAN.

For example, any of the following ways could be used:

   cpantorpm Foo::Bar
   cpantorpm http://some.host.com/some/path/Foo-Bar-1.00.tar.gz
   cpantorpm /tmp/Foo-Bar-1.00.tar.gz
   cpantorpm /tmp/Foo-Bar-1.00

When working with a CPAN module, you must use the form:

   Foo::Bar

instead of a file form:

   Foo-Bar
   Foo-Bar-1.00
   Foo-Bar-1.00.tar.gz

These are not currently supported.

When downloading from a URL, both ftp:// and http:// URLs are
supported (though others such as file:// and https:// are not
supported at this time).

For this script to work, the perl module must meet a few validity
requirements:

=over 4

=item Valid name format

The name of the distribution must be of the form:

   PACKAGE-VERS

if obtained from a local directory, or

   PACKAGE-VERS.EXT

if obtained from an archive (a local file, a URL, or from CPAN).  Here
VERS is any string which does NOT contain a dash (-).  EXT may be any
of the following extensions:

   .tar
   .tar.gz
   .tgz
   .tar.bz2
   .zip

=item Standard install script

The module must contain either a Build.PL or Makefile.PL script.  A
module using some other non-standard build procedure cannot be built
with this script.

=back

Getting the module in each of the 4 ways requires different system
requirements.  In general, the script will try several different ways
to get the module, and will only fail if all of the different methods
fail.

The following system requirements exist for the different ways of
obtaining a module:

=over 4

=item From a local directory

You must be able to run the system command 'cp -r' (to recursively copy
a directory) or be able to load the module File::Copy::Recursive.

=item From a local file

You must be able to run the system command 'cp' (to copy a file) or be
able to load the module File::Copy.

In addition, you must meet additional requirements for working with the
different types of archives as described next.

=item From a URL

To get a module from a URL, you have to have one of the following
packages installed:

   curl
   wget
   lynx
   links
   lftp

or be able to load one of the modules:

   LWP::UserAgent
   HTTP::Lite

In addition, you must meet additional requirements for working with the
different types of archives as described next.

=item From CPAN

To get a module from CPAN, you must be able to load one of the perl
modules:

   CPANPLUS::Backend
   CPAN

In addition, you must meet additional requirements for working with the
different types of archives as described next.

=back

In each case (except for obaining a module from a local directory),
once you have obtained the archive, you need to be able to extract it.

To do this, you need to meet the system requirements for the appropriate
type of archive:

=over 4

=item .tar, .tar.gz, .tgz files

You need to be able to run the system 'tar' command, or be able to
load one of the perl modules:

   Archive::Extract
   Archive::Tar

These modules will make use of other modules to handle .gz or .bz2
compression.

=item .zip files

You need to be able to run the system 'unzip' command, or be able to
load one of the perl modules:

   Archive::Extract
   Archive::Zip

=back

Once the package is obtained, in some cases it may be necessary to
apply patches or run a script in it to fix things that make it
not suitable for packaging.

=head1 PARSE VARIOUS PERL MODULES FILES FOR NECESSARY INFORMATION

Building an RPM correctly involves getting a great deal of information
from the module.  We have to know what features are provided by this
module, what features are required by the module to run, as well as
the description of the module, the author, etc.

This information can be obtained by a number of different files
including:

=over 4

=item Makefile.PL, Build.PL

Currently, these are only used to determine how the module should
be built.  Although they typically contain a great deal more information,
it is written as perl code and there is no reasonable way to get the
information from them.

However, one of the steps done by this script is to actually build
a Build script or Makefile (this ensures that the perl module can
be correctly built), and information can be extracted from them
since they do follow regular formats.

=item META.json, MYMETA.json

For a description of the type of data stored here, please refer to the
CPAN-Meta documentation on CPAN.

In order to interpret a JSON file, you have to be able to load one of
the following perl modules:

   Parse::CPAN::Meta 1.40
   JSON
   JSON::XS
   JSON::PP
   JSON::DWIW

Most of the information can be obtained from a complete JSON file.

=item META.yml, MYMETA.yml

For a description of the type of data stored here, please refer to the
CPAN-Meta documentation on CPAN.

In order to interpret a YAML file, you have to be able to load one of
the following perl modules:

   YAML
   YAML::Syck
   YAML::XS
   YAML::Tiny

Most of the information can be obtained from a complete YAML file.

=item Pod file

In most instances, some of the information (primarily the summary and
description of the module) must be obtained from a pod document.  This
will require one of the modules:

   Pod::Select
   Pod::Simple::TextContent

The script will need to determine which POD file to get this informaion
from (the primary POD file for the package).  Most of the time, the
script is able to determine which file to use, but if it fails, it
can be manually specified using the B<--mainpod> option.

=back

=head1 BUILD THE PACKAGE

The next step is to actually build the module.

This step is a departure from the way cpanspec and cpan2rpm work.  In
both of these scripts, the SPEC file contains the procedure for
building the perl module, but it is never tested to see if it works.

This has a couple significant advantages:

=over 4

=item It ensures that the package builds

A number of perl modules cannot be built automatically because the
scripts are interactive.  Unfortunately, the RPM build process does
not handle this well, so what you end up with is a hanging process
that (eventually) you will have to kill by hand.  In other cases, the
build process fails for other reasons.

When the build process is put in the SPEC file untested, the
RPM build process will either fail or hang.

This script avoids many of those problems.

=item It generates additional meta data

Both cpanspec and cpan2rpm would interpret the Makefile.PL and
Build.PL scripts directly to obtain information from them.
Since there is no guarantee that these scripts follow any
convention, I considered this a very poor option.

By actually building the module, it creates either a Makefile
or a _build hierarchy, and these DO follow regular conventions,
and information can be obtained from them with a much greater
chance of success.

=back

This script actually builds the module to ensure that it can be done.
It watches the process to see if it enters a state where it's waiting
for user input, and if it does, the process ends and the RPM is not built,
and you can then go in and correct the problem (typically by installing
some build prerequisite, or supplying a non-standard option to the
build process, or in the worst case, by providing a patch to the module
source that removes the interactive nature.

=head1 GENERATE A SPEC FILE

Much of the process of generating a spec file is taken from the
cpanspec package.

The first step in creating a SPEC file is to determine where the
RPM build hierachy lives (since that is where the SPEC file will live).
This script supports using the standard build hierarchy, or specifying
an alternate location.

If the B<--rpmbuild> option is used, it is used to specify the location
of the build hierarchy.  Otherwise, the standard location will be used.
If a location is specified, and if there is a B<~/.rpmmacros> file present,
the B<~/.rpmmacros> file must not contain the macro B<%_topdir> that is
different than the one specified by the B<--rpmbuild> option.  If
the macro does exist, you can use the B<--rpm-clean> option to specify a
clean version of the B<.rpmmacros> file be used.

The SPEC file created by this script does deviate from the recommended
form in one respect.  The recommended way to handle the list of
requirements and the list of features provided by an RPM is to leave
out these lists in the SPEC file and allow rpmbuild to generate them
automatically.  In the SPEC file, you only list changes to the
defaults.  In other words, you can add features that are required or
that the package provides that were not picked up automatically, or you
can add lines to the SPEC file to filter out features that you do not
want the rpm to depend on or provide.

Unfortunately, even though adding prerequisites and provided features
works well, removing them does not work nearly as smoothly.  The
methods for filtering prerequisites and features does not work well
cross platform (attempts that worked for redhat would not work for
openSuSE for example).

As a result, I do not let the SPEC file tell rpmbuild to generate these
lists.  Instead, I generate the lists (using the standard rpm utilities
when available, or using an included script when they are not) and
explicitly put them in the SPEC file.

=head1 CREATE THE RPM PACKAGES

Once the SPEC file is done, the RPM can be created using the standard
RPM tool 'rpmbuild'.

It uses the standard RPM file structure and creates both a source RPM
and a binary RPM.

=head1 SIGN THE RPM PACKAGES

This is an optional step.  If can be used to embed a GPG signature in
the package.

In order sign a package, you must have a GPG key available.  You must
have the gpg package installed on your system and you must have at least
one GPG key created.

The path to the GPG directory be specified by one of the following:

   the value of the --gpg-path option

   the value of the %_gpg_path rpm macro

   the value determined by gpg using any currently
   set environment variables

If no keyring is found, signing is not available.

The key to use is specified by:

   the value of the --gpg-name option

   the value of the %_gpg_name rpm macro

   the only key in the keyring (if the keyring
   contains exactly one key)

If the key cannot be uniquely determined, signing is not available.

The rpm command to sign a package is interactive.  In order to script
everything, it is necessary to use a tool like expect.  If such a tool
is not available, and if you are signing packages, this script will be
interactive.  Currently, if the B<expect> program is installed or the
perl B<Expect> module is available, signing can be done non-interactively
if either the --gpg-passwd or --gpg-passfile options are passed in.

=head1 INSTALL THE RPM

This is an optional step.

After the RPM is successfully built, it can be installed on the system.
This will be done in one of two ways.  If you are running this as root,
it will simply use the rpm command.  Otherwise, it will use B<sudo> to
run the rpm command.

=head1 STORE THE RPM IN A LOCAL YUM REPOSITORY

This is an optional step.

If the B<--yum DIR> option is passed in, the RPMs (both source and
binary) are copied in to a local yum repository.  The repository is
stored at B<DIR> and should have the following directories:

   RPMS
   SRPMS

RPMs will be stored in either the RPMS/<arch> directory (if it exists)
or directly in the RPMS directory.  <arch> is typicall something like
'noarch' or 'x86_64'.

=head1 CONFIG FILE

A config file can be created which sets options on a per-module
basis.  It can be either a YAML file (ending in .yaml or .yml) or
a JSON file (ending in .json).

A sample YAML file is:

   ---
   Crypt::SSLeay:
      - --config=--default

   Foo::Bar:
      - --name Foobar

Each line should contain one option of any of the forms:

   --opt=val
   --opt val
   -o    val

If val contains spaces, you should NOT put quotes around it.  Use:

   --summary This is the summary

instead of:

   --summary "This is the summary"

=head1 SYSTEM REQUIREMENTS

This script will try to function under many different situations, and
it will often try multiple methods to accomplish a task, and many of
those methods will be available on any common linux configuration.  As
such, a rigorous list of system requirements is overly complicated and
won't be listed here.  In the event that the script fails, it will list
the methods tried and you can make sure that one of them will function
on your host.

The most common requirements will be listed here.  In all probability, if
you meet these requirements, this script will run.

Since the most common way to obtain a module will be from CPAN, you will
need one of the following modules installed and correctly configured:

   CPAN
   CPANPLUS

To make sure it's configured, make sure you can run B<cpan> or B<cpanp>
at the command line and have it work.

If you will be applying patches to a package, you will need the B<patch>
command.

You also need to be able to read both YAML and JSON files included
in almost every module.  This means that you will need one JSON
module installed out of the following:

   JSON
   JSON::XS
   JSON::PP
   JSON::DWIW

and one YAML module from the following:

   YAML
   YAML::Syck
   YAML::XS
   YAML::Tiny

You will also need to be able to examine POD files using one of the
following modules:

   Pod::Select
   Pod::Simple::TextContent

You'll should have:

   Module::Build
   Module::Build::Tiny
   ExtUtils::MakeMaker

installed in order to build modules that use the Build.PL and Makefile.PL
scripts (both Module::Build and Module::Build::Tiny are supported).

In order to build the rpm, you need the B<rpmbuild> program.

This script also relies on the B<strace> program.  This is necessary
because many Makefile.PL and Build.PL scripts are interactive so when
you run them, they hang waiting for input.  Unfortunately, I was not
able to find any pure perl way to run a program as a child (or in a
thread) and monitor it to see if it's still running because it's doing
work, or still running because it's waiting on user input.  Though
somewhat crude, B<strace> can be used to determine that.

In order to sign packages, you must have the B<gpg> program installed,
and you must have a key set up to sign with.  In order to do this
non-interactively, you also need either the B<Expect> module or the
B<expect> program installed.

In order to install the package, you either must be running as root, or
have the B<sudo> program.  The B<sudo> command may be interactive,
depending on how you have it set up.

In order to install RPMs in a yum repository, the repository must exist.

=head1 HISTORY

This script is based loosely on Erick Calder's cpan2rpm script and
Steven Pritchard's cpanspec script.  Initially, I set out to modify
one or the other of them, but I found that the modifications that I
felt necessary were extensive enough that I decided a fresh
implementation was both faster and cleaner.

=over 4

=item cpan2rpm

cpan2rpm had basically the full functionality that I wanted.  It would
download a module, write a spec file for it, create an RPM, and then
install it.  The only functionality that was missing was some simple
functionality to add it to a local yum repository.  That would have been
very simple to add.  However, it suffered from several other significant
problems.

cpan2rpm is old.  It has not been supported since 2003.  It has
virtually no support for modules built using Build.PL scripts, and
adding it would have been quite complicated.

cpan2rpm is also not written as cleanly, or in a style that I'd like
to maintain, so it would take a bit of cleaning up to turn it into
something I'd want to maintain.

The main problem though is how it gets information from the
Makefile.PL script.  In order to get all of the information necessary
to create a SPEC file, there's a lot of information about the module
that needs to be examined.  Much of that information is stored in the
various META files in any new module distribution.  None of that is
used in cpan2rpm (which predates most of them), so that would have to
be added.  However, even with the META files, some information comes
from the Makefile.PL (or Build.PL script) such as the default install
location.

Since the data is in a script, cpan2rpm tries to be intelligent about
extracting the information.  It loads in the Makefile.PL script,
modifies it (by turning 'exit' into 'return') and evals it.  The
theory is that by eval'ing it, you end up with the appropriate data
structure that you can examine.

The modifications that it makes are completely unjustified though.  It
makes drastic assumptions about what the Makefile.PL file looks like,
and I can think of any number of cases where turning 'exit' into
'return' won't produce the result you want.

As such, cpan2rpm's handling of the Makefile.PL file needed to be
replaced entirely (and since that makes up a significant portion of
the script, that justified a complete rewrite).

In addition, if the script contained in Makefile.PL is interactive,
cpan2rpm hangs silently while trying to eval it, and there is no
easy way to determine what is causing it to hang.

=item cpanspec

cpanspec is much cleaner in most respects.  It is well written, handles
both Makefile.PL and Build.PL installs, and handles all of the new
META files.

However, it has a few other problems.

It was written specifically for redhat distributions (redhat, centos,
fedora) and hardcodes some of the redhat specific paths in it.  Other
RPM based distributions (such as OpenSuSE which I use) use different
paths.  At the very least, the cpanspec file would need to be modified
to add options to override the defaults.

cpanspec also makes assumptions about where you want to install the
modules.  It will only install in the vendor location of the primary
perl installation.  If you want to install them anywhere else, you
are out of luck.

But the single biggest weakness was how it handles the Makefile.PL and
Build.PL scripts.  Rather than evaluating the code, cpanspec just opens
them and tries to parse information from them.

Again, given that these are perl scripts, the only reliable way to
parse them is to actually use the perl interpreter.  Although most
modern modules include Makefile.PL or Build.PL scripts that follow
certain conventions, it is by no means guaranteed, so I was not
satisfied with this assumption.

As with cpan2rpm, cpanspec does not deal with interactive installs.  It
simply shuffles the problem to another location.  In this case, once
the SPEC file is created, it is necessary to run rpmbuild, and this
will hang.

=back

Due to the weaknesses in both of the existing alternatives, I decided
a clean rewrite was in order.  The goals were:

=over 4

=item Beginning-to-end functionality

cpantorpm will download the module from CPAN, create the SPEC file,
generate an RPM, install it, and store the RPM in a local YUM repository
for other hosts to use.

=item Cross platform

cpantorpm will work on any RPM based distribution (though this is only
tested on redhat and OpenSuSE to date).  Also, many of the steps can
be done in many different ways, different one of which may be
available by default platforms, so most steps will try more than one
way to accomplish the task.

For example, to download a module, cpantorpm will use the CPAN module,
the CPANPLUS module, and various tools to download via HTTP (such as
wget, curl, etc.).

=item Correctly handle Makefile.PL and Build.PL

The only way to correctly handle these scripts is to actually build the
module.  The files generated contain all of the information in a
standard format, and we can get it without making any assumptions about
the format of these scripts.

=item Handle interactive installs

Many installs are potentially interactive.  If you are missing
prerequisites, many modules will stop and ask you if you want to
install them first.

cpantorpm traps this behavior and allows you to handle it, rather than
hanging for an unknown reason.

Note: by 'handle it', it will not try to install them.  Rather, the
cpantorpm script will let you know what was being asked, and then
exit, and at that point, it's up to you to correct the problem.  A
future version of cpantorpm may include some automatic handling of
missing prerequisites which is the primary cause of interactive
installs hanging.

=back

All that being said, I have borrowed ideas (and in rare instances,
code) freely from cpanspec and cpan2rpm.  I'm very grateful to the
authors of both cpan2rpm and cpanspec who's work has made mine much
easier.

Hopefully, cpantorpm takes the best of both worlds and improves on
that.

=head1 KNOWN BUGS

None known.

=head1 BUGS AND QUESTIONS

If you find a bug in cpantorpm, there are three ways to send it to me.
In order of preference, they are:

=over 4

=item GitHub

You can submit it as an issue on GitHub.  This can be done at the following
URL:

L<https://github.com/SBECK-github/App-CPANtoRPM>

This is the preferred method.  Please submit problems requests as GitHub issues
if at all possible.

=item Direct email

You are welcome to send it directly to me by email.  The email address
to use is:  sbeck@cpan.org.

Please note that because cpan.org addresses are published, they are used by
a lot of spammers and phishers.  Please include the word cpantorpm
in the subject line of ALL messages sent to my cpan.org address or it will
likely be missed.

=item CPAN Bug Tracking

You can submit it using the CPAN tracking tool.  This can be done at the
following URL:

L<http://rt.cpan.org/Public/Dist/Display.html?Name=App-CPANtoRPM>

There was discussion of halting this service a while back (though it continues
to function), so only use this as a last resort.

=back

Please do not use other means to report bugs (such as forums for a specific
OS or Linux distribution) as it is impossible for me to keep up with all of
them.  These are the current methods that are guaranteed to notify me.

When filing a bug report, please include the following information:

=over 4

=item B<cpantorpm version>

Please include the version of cpantorpm you are using.  You can get
this by running:

   cpantorpm -v

=back

If you find any problems with the documentation (errors, typos, or items
that are not clear), please send them to me. I welcome any suggestions
that will allow me to improve the documentation.

=head1 SEE ALSO

cpan2rpm  - Erick Calder's script to generate RPMs

cpanspec  - Steven Pritchard's script to generate spec files

=head1 LICENSE

This script is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=head1 AUTHOR

Sullivan Beck (sbeck@cpan.org)

=cut
