class: middle, center ## Fatpack It! ### Full-featured Perl apps in a single file .title[] [https://cleverdomain.org/ye2018/](https://cleverdomain.org/ye2018/) --- ## Goals ??? So the talk is about how to make a full-featured app and bundle it into a single file. Why would you want to do that? -- * Run on a variety of machines with minimum effort * Most Unix machines have Perl out of the box -- * Let people run and contribute to our apps without caring about Perl -- * General-purpose utilities -- * Tools in a perl-hostile $WORK ??? We might be here because we care about Perl, but the real world is full of users and coworkers who don't. Whether for general-use software or a work scenario, minimizing toolchain friction is a win. I'm not suggesting "sneaking Perl in"... but maybe I am :) -- * Make Perl seamless --- ## Pre-history ??? How to install and run a Perl script you found on the internet, somewhere around the year 2000... -- * Download a script from somewhere, run it -- * `Can't locate Foo/Bar.pm in @INC` -- * Run CPAN shell -- * Go through the configuration -- * Set a bunch of vars to install as non-root -- * `cpan Foo::Bar` -- * Wait a while... -- * Try the script again -- * Repeat -- * Or just write code with no non-core dependencies :( ??? Lots of people do this, it makes me sad. --- ## Prior Art * `local::lib` eased the pain of non-root installation -- * `cpanminus` made zero-to-working modules much faster -- * Structuring apps as modules let us put deps in Makefile.PL * `cpanm --installdeps .` -- * But we can go much further... ??? (and here are some tools I'm going to show you to do it) --- ## FatPack * Uses `@INC` hooks to load modules from somewhere other than disk -- * Like a hash in `main::` -- * `App::FatPacker` bundles everything into one file for you -- * Only works for Pure-Perl --- ## PAR * A different way of bundling Perl apps into a single file -- * Supports XS -- * Can make executables -- * Quirky -- * Not going to mention it much more this talk --- ## Moo * A very useful subset of Moose ??? * Moose without MOP * "Moose without the antlers" * "Slightly less than two-thirds of Moose" -- * Fast -- * No XS required -- * Auto-upgrades to Moose -- * Substantial ecosystem -- * Recommended for module authors (by me) ??? As a module author, if you don't need all of the features of Moose, or if you're uncomfortable with Moose as a dep, use Moo! It leaves the choice in your users' hands! --- ## CLI::Osprey ??? So with FatPack and Moo you can create a substantial app and pack it into a single file. If you've got an interesting app, you probably need a way to structure it and handle command-line arguments. -- * `MooX::Options` is like `MooseX::Getopt` for Moo -- * But that doesn't mean it's pure-perl friendly * `Text::LineFold` is hard to replace for east-Asian character support -- * And I had a few other things I wanted to improve -- * So I wrote my own --- ## CLI::Osprey Example ```perl package Hello; use Moo; use CLI::Osprey -desc => "Example App"; option 'greeting' => ( is => 'ro', format => 's', doc => 'What to say to the world', default => 'Hello', ); sub run { my $self = shift; print $self->greeting, ", World!\n"; } package main; Hello->new_with_options->run; ``` ??? Supports 99% of what MooX::Options does, and then some. --- ## And it does stuff <pre> <b>$ ./hello</b> Hello, World! -- <b>$ ./hello --greeting Yo</b> Yo, World! -- <b>$ ./hello --man</b> </pre> --- name: hello2 ## And it does stuff <pre> <b>NAME</b> hello <b>SYNOPSIS</b> <b>hello</b> [<b>--greeting</b> string] [<b>-h</b>] [<b>--help</b>] [<b>--man</b>] <b>OPTIONS</b> <b>--greeting</b> <u>string</u> What to say to the world <b>-h</b> show a short help message <b>--help</b> show a long help message <b>--man</b> show the manual </pre> --- ## It's also like App::Cmd ```perl package MyApp; use CLI::Osprey; option 'debug' => ( is => 'ro', default => 0, doc => 'Enable debug mode', ); subcommand 'frobnicate' => 'MyApp::Cmd::Frobnicate'; subcommand 'encabulate' => 'MyApp::Cmd::Encabulate'; ``` --- ## It's also like App::Cmd * Supports options on main and sub commands -- * Subcommand receives an instance of the parent command -- * Nest more than one deep if you like --- ## And it's suitably Moosey * Make use of types to validate arguments -- * Use builders all over the place -- * Wrap stuff with before / after / around etc. -- * Powerful code without too much work --- ## Diversion: CPANfile ??? Okay, we've got this stuff to let us stuff an app into a single file, but how can we make the build process easier? -- * Like Makefile.PL, but for apps, not modules -- * Declares dependencies -- * Not concerned with build & install -- * Defined spec -- * Supported by cpanm and cpm --- ## cpm -- * Awesome CPAN client -- * Parallel installation -- * Supports static-install -- * **FAST!** -- * Fatpacked into its own git repo * Add it as a git submodule and `perl cpm/cpm install -L local` -- * This is awesome. Really. --- ## Like really awesome. <iframe src="https://player.vimeo.com/video/275431863" width="640" height="356" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> --- ## Environment hacks ```sh export PUREPERL_ONLY=1 export PERL_JSON_BACKEND=JSON::backportPP export B_HOOKS_ENDOFSCOPE_IMPLEMENTATION=PP export PACKAGE_STASH_IMPLEMENTATION=PP export PARAMS_VALIDATE_IMPLEMENTATION=PP export LIST_MOREUTILS_PP=1 export MOO_XS_DISABLE=1 ``` Make sure pure-perl dependencies get packed in even if the machine you're building on has the XS versions. ??? There's an issue with certain XS-optional modules like `Sub::Identify` installing their PP part into the arch directory. I'm working on upstreaming a fix for that into `App::FatPacker` sometime soon. --- ## Build script, all together ```sh git submodule update --init perl cpm/cpm install -L local --target-perl 5.14.0 --with-develop --without-test export PERL5LIB=$PWD/lib:$PWD/local/lib/perl5 export PATH=$PWD/local/bin:$PATH perl -c myapp.pl || exit 1 # If it has errors, don't bother trap 'rm -rf .build fatlib fatpacker.trace fatpacker.trace.bak packlists' EXIT fatpack trace myapp.pl fatpack packlists-for $(cat fatpacker.trace) > packlists fatpack tree $(cat packlists) # Clean up some cruft find fatlib -type f -exec perlstrip {} \; # Small is beautiful fatpack file myapp.pl > myapp chmod +x myapp ``` ??? Goes from a clean git checkout with no generated stuff to a built result in one shot. --- class: center ## Worked Example Antenna analyzer: [https://github.com/arodland/swr](https://github.com/arodland/swr) --- ## Vague Thoughts * Windows? * Doesn't have Perl usually, but people don't mind installers so much * Use PAR to produce an EXE? -- * GUI? * Cross-platform GUI is hard enough * Cross-platform GUI without XS is almost impossible -- * Web app serving to localhost * Pure-perl web frameworks and HTTP servers are available * Use `xdg-open`, `start`, etc. to trigger a browser * A compromise, but it's something --- class: middle, center ## Thanks! .title[] Any questions?