Intro. to Go Programming Language

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Reasons People are Here

  • Curious whether go is mature enough to be chosen for production
  • Manipulate data with go
  • Alternative to Python?
  • Iz teh new hotness
  • why compile anything when scripting languages are great
  • Argue against the “here’s some crazy new thing we should try”
  • Automation, TDD, tooling?
  • Statically-typed compile-time, checking

Why give this talk

  • History of building stuff. Http is how they communicate, but not really websites.
  • Lots of machines doing stuff and generating data, but some people/groups want different data.
  • Getting data from one place, ETLing it, and taking it to somewhere
  • Before: used logstache: JRuby, but really slow, took a minute to spin up the JVM.
  • Heard about Go, one of the benefits is that it’s a whole lot faster. It compiles down to binary executable. Helps avoid dependency hell because you can deliver an executable to ops team for deployment (and maybe some docs) [security caveat: if you have a dependency with security exploit, you have to redeploy the entire package).
  • Written by Ken Thompson and Rob Pike of Unix and C lineage. Google asked them: if you would rewrite C today, here is some money, do it.
  • Alternatives: Rust, Erlang, Haskell
  • But Go is a very pragmatic language… was written for C and C++ programmers who actually have NOT flocked to Go. C++ gives way more power over stuff (though has a huge learning curve and potential to do things wrong), but if you’re already good at C++, why learn something new that is more controlled. Instead, Python/PHP/Ruby/Java folks are loving it because it’s not super abstract: there are good primitives, memory management (though you have control over GC).
  • You can learn the Go language in a weekend and be productive in it in very little time.
  • At least an order of magnitude performance benefit over Ruby/Python.
  • The product that the Mozilla team decided to first try Go with is not a customer facing product. Backend, data-processing that replaces an existing system with exactly the same functionality. “If no one notices, we’ve done it right”. Can easily benchmark against the existing system. … and it has paid off!
  • HEKA: https://github.com/mozilla-services/heka

How to Learn

  • http://tour.golang.org
  • Capital lettered functions are exported/public; lowercase are private to the package
  • Everything is within one directory, but all functions can be arbitrarily moved within that directory (unlike python where filenames matter when importing).
  • Tooling is great. Optimized for the developer experience.
  • gofmt - will automatically format your code in the idiomatic manner; every single developer has this hooked up to format-on-save
  • GDB works with Go for debugging. Bug because Go is compiled, you can’t interact dynamically with the current state
  • Can return multiple variables from a function
  • Not much metaprogramming
  • There are no object hierarchies or inheritance trees. You can have a struct that has functions on it. It will automatically dereference pointers to structs, so you can write x.y.z where x is a struct, and the return value of y is another struct.

Concurrency

  • Goroutines: concurrent processing
  • Was initial concern that if something blew up in production, it would be tough to do post-mortem analysis to fix it
  • Have yet to crash go program without a solid stack trace that doesn’t point to what broke
  • Can run on multiple cores
  • Channels: can send and receive values between goroutines. Automatically manages blocking and back-pressure.

Other stuff

  • TDD, benchmarks: https://github.com/smartystreets/goconvey , gomock (ehh), gospec (smooth)
  • Package Management: there are 17 different ones == none; cmake vs cgo
  • Gorilla (pylons), Martini (more golike restful web framework)

Summary

  • Go is badass multi-threaded, multi-process language
  • Ruby/Python/PHP/Java programmers are loving it
  • Has awesome interactive documentation at golang.org