rse-conf-go-2016

rse-conf-go-2016 is a simple repository holding sources for the Go hands-on session of the Go workshop for the RSE conference (2016).

The slides are here.

Bootstrapping the work environment

Installing the Go toolchain

The Go hands-on session obviously needs for you to install the Go toolchain.

There are 3 ways to do so:

• install Go via your favorite package manager (yum, apt-get, fink, ...)
• install Go via docker
• install Go manually.

While all 3 methods are valid ones, to reduce the complexity of the debugging/configuration/OS matrix, we'll only recommend the last one.

Also, if you are using the VMs made available by RSE, Go (1.6.3) should have already been properly installed.

Installing Go manually

This is best explained on the official page: https://golang.org/doc/install

On linux-64b, it would perhaps look like:

$ mkdir -p $HOME/workshops/c3/root
$ cd $HOME/workshops/c3/root
$ curl -O -L https://golang.org/dl/go1.6.3.linux-amd64.tar.gz
$ tar zxf go1.6.3.linux-amd64.tar.gz
$ export GOROOT=$HOME/workshops/c3/root/go
$ export PATH=$GOROOT/bin:$PATH

$ which go
${HOME}/workshops/c3/root/go/bin/go

$ go version
go version go1.6.3 linux/amd64

$ which godoc
${HOME}/workshops/c3/root/go/bin/godoc

Setting up the work environment

Like python and its $PYTHONPATH environment variable, Go uses $GOPATH to locate packages' source trees. You can choose whatever you like (obviously a directory under which you have read/write access, though.) In the following, we'll assume you chose $HOME/workshops/c3/gopath:

$ mkdir -p $HOME/workshops/c3/gopath
$ export GOPATH=$HOME/workshops/c3/gopath
$ export PATH=$GOPATH/bin:$PATH

Make sure the go tool is correctly setup:

$ go env
GOARCH="amd64"
GOBIN=""
GOCHAR="6"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="$HOME/workshops/c3/gopath"
GORACE=""
GOROOT="$HOME/workshops/c3/root/go"
GOTOOLDIR="$HOME/workshops/c3/root/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"

(on other platforms/architectures, the output might differ slightly. The important env.vars. are GOPATH and GOROOT.)

Testing go get

Now that the go tool is correctly setup, let's try to fetch some code. For this part, you'll need the following tools installed to actually retrieve the code from the repositories:

• git

Without further ado:

$ go get -u -v github.com/sbinet/rse-conf-go-2016/cmd/rse-hello
github.com/sbinet/rse-conf-go-2016 (download)

go get downloaded (cloned, in git speak) the whole github.com/sbinet/rse-conf-go-2016 repository (under $GOPATH/src) and compiled the rse-hello command. As the compilation was successful, it also installed the rse-hello command under $GOPATH/bin.

The rse-hello command is now available from your shell:

$ rse-hello
Hello RSE-Go-2016!

$ rse-hello you
Hello you!

Setting up your favorite editor

Extensive documentation on how to setup your editor (for code highlighting, code completion, ...) is available here:

https://github.com/golang/go/wiki/IDEsAndTextEditorPlugins

At the very least, you should try to install and setup goimports as explained here:

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

goimports provides automatic code formating as well as automated insertion/deletion of used/unused packages (in your import package statements.)

Documentation

The Go programming language is quite new (released in 2009) but ships already with quite a fair amount of documentation. Here are a few pointers:

• http://golang.org/doc/code.html
• http://tour.golang.org
• http://golang.org/doc/effective_go.html
• http://dave.cheney.net/resources-for-new-go-programmers
• http://gobyexample.com

For more advanced topics:

• http://talks.golang.org
• http://blog.golang.org
• https://groups.google.com/d/forum/golang-nuts (Go community forum)
• the internets. typical queries are go something or golang something