This document discusses making CPAN modules static installable by setting the x_static_install flag in the META.json file. Typically, CPAN modules are installed using Makefile.PL, but static installation allows them to be installed more quickly without executing Makefile.PL. The presenter demonstrates how to modify a CPAN module using Minilla to set x_static_install to 1, making it static installable. Static installation is simpler, faster, and safer than typical installation as it avoids executing arbitrary code.

1. Make your CPAN
module static installable
Shoichi Kaji

2. Me
CPAN, github: skaji
Shoichi Kaji

3. Agenda
• Typical CPAN module installation
• Introduce static install
• Why do you adopt static install?
• DEMO
• How to make your CPAN module static installable
• Conclusion

4. Typical way
• This is a typical CPAN module installation
• Bundled Makefile.PL knows how to configure/build/test/install the
CPAN module
• So you don’t need any tools to install CPAN modules; this is good
• CPAN modules can do almost anything in Makefile.PL; this is powerful
wget http://www.cpan.org/.../Module-0.1.tar.gz
tar xzf Module-0.1.tar.gz
cd Module-0.1
perl Makefile.PL # or perl Build.PL
make
make test
make install

5. BTW
• Nowadays, a lot of people use CPAN clients,
such as cpanm to install CPAN modules
• If CPAN modules are not "complicated", then
CPAN clients easily expect how to configure/
build/test/install them
• … do we really need Makefile.PL?

6. Introduce static install
• Now we have the concept static install introduced by
Leon Timmermans (sorry if I am wrong)
• That is, if CPAN modules
- are not "complicated"
- set x_static_install 1 in their META.json
then CPAN clients may configure/build/test/install them
in the common way without executing Makefile.PL
• cpanm-menlo and cpm already support static install

7. Why do you adopt static
install?
• Fast
we don’t need to execute Makefile.PL, which
makes CPAN module installation much faster
• Simple
People can easily expect results (eg: which files are
installed and where)
• Safe
There is no place to execute arbitrary code during
configure/build/install steps

8. DEMO
https://gist.github.com/skaji/
24de4a819ca4a84b2018f5ee996ac52a

9. How to make your CPAN
module static installable
• First, check your CPAN modules are not
complicated
• pm files are in lib/
• executable files are in script/ (if any)
• prereqs are declared in META.json statically
• no xs file, no Module_pm.PL file

10. How to make your CPAN
module static installable
• Here I assume you use Minilla
• Modify toml.minil as follows
• Then your module is static install ready 😄
> minil build
> grep x_static_install META.json
"x_static_install" : 1
name = "Your-Module"
module_maker = "ModuleBuildTiny"
[Metadata]
x_static_install = 1

11. Conclusion
• CPAN ecosystem uses Makefile.PL/Build.PL to install
CPAN modules
• It is powerful, but often overly complicated
• Now we have the concept static install, which is much
simpler and faster
• To make CPAN modules static installable, set
x_static_install 1 in META.json
• Let’s make CPAN ecosystem simpler 👍

12. See also
• My blog post
http://blogs.perl.org/users/shoichi_kaji1/2017/03/
make-your-cpan-module-static-installable.html
• The spec of static install
https://github.com/Perl-Toolchain-Gang/cpan-static
• An implementation of static install in Menlo
https://github.com/miyagawa/cpanminus/pull/467