Carton CPAN dependency manager

Transcript

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

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2. Managing CPAN
   Dependencies
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3. Case Study:
   (Poor) Web Development
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4. You’re writing a new web app.
   You don’t wanna reinvent wheels.
   Want to use as many CPAN deps.
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5. Fine.
   Get them from CPAN,
   install on your machine.
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6. >  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
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7. Test it...
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8. Works? Ship it!
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9. Deployment
   Set up new production servers.
   Install CPAN modules
   (until the errors are gone)
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10. Few weeks later...
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11. Your website is popular!
    Need more web servers!
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12. Re-Deployment
    Set up new production servers.
    Install CPAN modules
    (until the errors are gone)
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13. “Crap, Web::Framework has been
    updated to 1.4 and many APIs
    have been changed or deprecated!”
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14. Rollback
    Log in to the old web server.
    Check Perl module versions.
    Install them on the new server.
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15. “Crap, this author deleted
    the version 1.20 we want.
    Let’s go to BackPAN...”
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16. “Crap, version 1.20 doesn’t actually work
    with the newer LWP 6 that we just
    installed! Have to downgrade this too...”
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17. and so on.
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18. What was wrong?
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19. • Dependency declaration
    • Isolated Perl environments
    • Version controls/history
    • Dependency analysis
    • Repeatable deployments
    • etc.
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20. Many existing solutions
    MyCPAN, DPAN, CPAN::Mini::Inject,
    OrePAN, Shipwright
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21. None of those
    didn’t quite work for me.
    (Or I haven’t even tried)
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22. So I wrote a new one.
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23. Carton
    https://github.com/miyagawa/carton
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24. Inspired by...
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25. Friday, October 14, 2011
    

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26. • 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
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27. Local perl environment
    Using local::lib and cpanm -L
    Each app has an isolated local library path
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28. Fast and safe install
    cpanm 1.5
    Saves MYMETA.json and install meta info
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29. Dep tree analysis
    Rebuild the dependency tree from meta info
    Checks if anything is missing/superflous
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30. Locking versions
    Versions are saved in carton.lock
    including dependencies
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31. Easy Redeployment
    Reinstall exactly the same set of modules
    on another prod/development machines.
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32. Single-file, VCS friendly
    You can add carton.lock to git
    update whenever you update modules
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33. Safe and easy rollback
    revert the lock file and redeploy
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34. DEMO
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35. >  cpanm  Carton
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36. WARNING
    It is beta software, some features are
    missing or not working correctly (yet).
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37. github.com/miyagawa/carton
    irc.perl.org #carton
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38. Questions?
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39. Thanks!
    twitter.com/miyagawa
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