Carton CPAN dependency manager

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Carton Tatsuhiko Miyagawa YAPC::Asia 2011 Tokyo Friday, October 14, 2011

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Managing CPAN Dependencies Friday, October 14, 2011

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Case Study: (Poor) Web Development Friday, October 14, 2011

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You’re writing a new web app. You don’t wanna reinvent wheels. Want to use as many CPAN deps. Friday, October 14, 2011

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Fine. Get them from CPAN, install on your machine. Friday, October 14, 2011

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> cpanm Web::Framework installed LWP-‐5.912 installed Plack-‐0.9980 installed Web-‐Framework-‐1.20 > cpanm JSON::Fast installed JSON-‐Fast-‐1.91 > cpanm MIME::Parser::XS installed MIME-‐Parser-‐XS-‐0.20 Friday, October 14, 2011

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Test it... Friday, October 14, 2011

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Works? Ship it! Friday, October 14, 2011

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Deployment Set up new production servers. Install CPAN modules (until the errors are gone) Friday, October 14, 2011

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Few weeks later... Friday, October 14, 2011

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Your website is popular! Need more web servers! Friday, October 14, 2011

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Re-Deployment Set up new production servers. Install CPAN modules (until the errors are gone) Friday, October 14, 2011

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“Crap, Web::Framework has been updated to 1.4 and many APIs have been changed or deprecated!” Friday, October 14, 2011

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Rollback Log in to the old web server. Check Perl module versions. Install them on the new server. Friday, October 14, 2011

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“Crap, this author deleted the version 1.20 we want. Let’s go to BackPAN...” Friday, October 14, 2011

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“Crap, version 1.20 doesn’t actually work with the newer LWP 6 that we just installed! Have to downgrade this too...” Friday, October 14, 2011

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and so on. Friday, October 14, 2011

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What was wrong? Friday, October 14, 2011

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• Dependency declaration • Isolated Perl environments • Version controls/history • Dependency analysis • Repeatable deployments • etc. Friday, October 14, 2011

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Many existing solutions MyCPAN, DPAN, CPAN::Mini::Inject, OrePAN, Shipwright Friday, October 14, 2011

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None of those didn’t quite work for me. (Or I haven’t even tried) Friday, October 14, 2011

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So I wrote a new one. Friday, October 14, 2011

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Carton https://github.com/miyagawa/carton Friday, October 14, 2011

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Inspired by... Friday, October 14, 2011

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Friday, October 14, 2011

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• App-speciﬁc local environment • Fast and safe install • Dep-tree analysis, including versions • Locking module versions • Easy Redeployment • Single-ﬁle, VCS friendly • Safe and easy rollback Friday, October 14, 2011

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Local perl environment Using local::lib and cpanm -L Each app has an isolated local library path Friday, October 14, 2011

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Fast and safe install cpanm 1.5 Saves MYMETA.json and install meta info Friday, October 14, 2011

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Dep tree analysis Rebuild the dependency tree from meta info Checks if anything is missing/superﬂous Friday, October 14, 2011

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Locking versions Versions are saved in carton.lock including dependencies Friday, October 14, 2011

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Easy Redeployment Reinstall exactly the same set of modules on another prod/development machines. Friday, October 14, 2011

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Single-ﬁle, VCS friendly You can add carton.lock to git update whenever you update modules Friday, October 14, 2011

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Safe and easy rollback revert the lock ﬁle and redeploy Friday, October 14, 2011

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DEMO Friday, October 14, 2011

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> cpanm Carton Friday, October 14, 2011

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WARNING It is beta software, some features are missing or not working correctly (yet). Friday, October 14, 2011