Creating a microservice for the 1st time with go

Transcript

1. Creating a microservice
   for the 1st time with go
   Henrique Vicente
   

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2. Go is an open source programming language that makes it
   easy to build simple, reliable, and efficient software.
   golang.org
   Robert Griesemer, Rob Pike and
   Ken Thompson started sketching
   the goals for a new language on
   the white board on September 21,
   2007.
   

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3. Go is a programming language
   designed by Google to help solve
   Google's problems, and Google
   has big problems.
   https://talks.golang.org/2012/splash.article
   

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5. An attempt to combine the
   ease of programming of an
   interpreted, dynamically
   typed language with the
   efficiency and safety of a
   statically typed, compiled
   language.
   

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6. Influenced by
   • C family (basic syntax)
   • Pascal / Modula / Oberon family (declarations,
   packages)
   • Newsqueak, Limbo (concurrency)
   • Unix
   

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7. Design
   • Multi-value returns
   • No exception handling. Pleasant error handling.

   http://blog.golang.org/error-handling-and-go
   • Gourotines instead of threads
   • Object-oriented? Yes and no.

   No type hierarchy. Interfaces.
   • No pointer arithmetic for safety:

   no memory illegal address risk
   • Garbage collected
   

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10. Quality tools
    • go fmt
    • go lint
    • go vet
    • go test
    • go tool cover
    

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11. go get github.com/henvic/picel
    • Programming time?
    

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13. • Package main: executable program
    • Others: shared libraries
    • Imports:

    - don’t use relative internally

    - use the path to where the repo is published
    • Subpackages = subdirectories
    

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16. No official package
    manager
    • The designers of the language decided not to
    do it for a reason.
    • But what if you want to guarantee a specific
    package version?

    

    https://code.google.com/p/go-wiki/wiki/
    PackageManagementTools
    

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17. many alternatives
    • godeps
    • gpm: https://github.com/pote/gpm
    

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18. Building
    • go build
    • You get a single binary by default.
    • gox tool to build to multiple platforms easily

    or just use https://gobuilder.me/
    

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19. The go way
    • Unused variable?
    • Unused import?
    • Unused?

    

    = No compiling :( … :)
    • Just discovered: fix it automagically :)

    http://godoc.org/golang.org/x/tools/cmd/goimports

    Productivity += 1000
    • godoc -http=:6000 to see the docs on your computer or use
    godoc.org
    

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23. $GOPATH
    • Go likes to have all your src, pkg, bin inside a
    $GOPATH
    • But don’t worry. This doesn’t matter for end users
    of your application, given you’re release
    compiled binaries.
    

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25. Useful packages, methods
    • fmt.Println(“like console.log”)
    • fmt.Sprintf(“%+v is %v old”, person,
    person.Age())
    • flag: ./cmd -backend “https://google.com/”

    Flag: backend, value: https://google.com/
    • number, err := strcov.Atoi(“2442”)

    number is 2442 (int), err is nil
    

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26. OOP: image.Name()

    with multiple return params
    Code: https://goo.gl/Ma2ITn
    

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28. “Dockerifying
    • Docker is built in go
    • We’ve a microservice that is designed to work
    with default options
    • Why not build a docker container for it?
    

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29. Dockerfile
    FROM golang:onbuild
    MAINTAINER Henrique Vicente
    RUN apt-get update
    RUN apt-get install -y \
    imagemagick \
    webp
    EXPOSE 8123
    

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30. Docker Hub Registry
    • Add repo for automatic building on Docker Hub
    Registry to have your package certified
    • You can install with

    docker pull henvic/picel
    • See also Dockerfile.dev
    

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31. Some nice go projects
    srvdir
    

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32. Questions?
    

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