eng-golang-workshop

BBC Gophers — Go Language Workshop

func main() {
	fmt.Println("Hello, BBC Gophers!")
}

The Workshop

We are on Slack in the #eng-golang channel.

Our workshop text is: The Go Programming Language by Alan Donovan and Brian W. Kernighan

Work through the course text at a speed that suits you. We also have meetups booked to meet to chat about Go and the book etc. So just join in any time! :)

1. Begin

To begin, create your own directory in the workspaces directory, work through the book exercises, and add your code there. You can add your code in separate directories if you're using Go Modules or if you're using a GOPATH you could structure your code as in the GOPATH Project Structure section.

If you need the exercises from the book, they're available in exercises.tar.gz zipped archive but these are already in the book so you might not need them.

2. Installing Go

a. Home/Linuxbrew

It may be convenient to install the latest version of Go through the Homebrew and Linuxbrew package managers.

brew install go

b. Install with Binary Distributions

The https://golang.org/dl/ page contains distros for Windows, MacOS, Linux, and source. The installation instructions explains how to install them.

3. Getting the Workshop Code

You can grab the code samples used in the book (which you update for a bunch of the exercises) by running such as:

go get gopl.io/ch1/helloworld

(This will get the helloworld code, plus the other examples).

4. Building and Running Go

There are two main options, by setting a GOPATH and having all of your code in one location or using Go Modules which allow you to split your code into separate locations. It might be easier to use a GOPATH pointing to all of your workshop code but you might find modules more appropriate.

a. Running Go with a GOPATH

The traditional way to run/build Go code (prior to Go Modules) is using a GOPATH. You should set your $GOPATH to your current directory, such as:

export GOPATH=/home/gopherg/eng-golang-workshop/workspaces/gogopher

To run some code you can then use:

go run gopl.io/ch1/helloworld

(which actually builds then executes /home/gopherg/eng-golang-workshop/workspaces/gogopher/src/gopl.io/ch1/helloworld/main.go)

To build it and output in your $GOPATH\bin directory:

go build -o $GOPATH/bin/helloworld gopl.io/ch1/helloworld

To get another module (such as the imaginary some/dependency):

go get github.com/some/dependency

...and this will then be downloaded to $GOPATH/src/github.com/some/dependency and imported with import "github.com/some/dependency"

GOPATH Project Structure

When using GOPATH your project structure may be something like:

workspaces
    gogopher\
        bin\
            helloworld
            ...
        src\
            gogopher.io\
                ch1\
                    ex1_1\
                        main.go
                ...

b. Running Go with Go Modules)

Go modules are an new feature in Go 1.11 which removes the need to have a $GOPATH set.

To use modules in your project directory, run:

go mod init example.com/foo

...where example.com is replaced with your own domain name (or something like github.com if your code is in a github repo) and foo is your package/component name. This will create a file called go.mod.

If you have a main function in your project directory you can also run your code using:

go run .

...and build it using:

go build .

...etc.

To include a module to your project you can add the external module to your go.mod file which would look like:

module example.com/foo

require (
    github.com/some/dependency v1.2.3
)

...then import it and use it in your code:

package main

import "github.com/some/dependency"

func main() {
    dependency.f()
}

Your own local packages are imported such as import "example.com/foo/package".

5. Development Environments

a. Delve (Debugger)

Delve is is a debugger for Go. To install run:

go get -u github.com/derekparker/delve/cmd/dlv

To see the available commands, run dlv then help at the (dlv) prompt.

b. GoLand

GoLand is a new commercial Go IDE by JetBrains aimed at providing an ergonomic environment for Go development.

The new IDE extends the IntelliJ platform with coding assistance and tool integrations specific for the Go language.

c. Emacs

If you follow similar instructions to get go support for emacs (OS X) as below http://tleyden.github.io/blog/2014/05/22/configure-emacs-as-a-go-editor-from-scratch/

And you run into the following error when trying to get auto-complete to work.

Error running timer ‘ac-update-greedy’: (file-missing "Searching for program" "No such file or directory" "gocode")
Error running timer ‘ac-show-menu’: (file-missing "Searching for program" "No such file or directory" "gocode")
Error running timer ‘ac-update-greedy’: (file-missing "Searching for program" "No such file or directory" "gocode"

Then the problem is probably down to gocode not being available in your path: https://emacs.stackexchange.com/questions/10722/emacs-and-command-line-path-disagreements-on-osx

So if you edit /etc/paths.d/go and add the path to the bin directory of your project it should fix problem.

d. Atom

Atom supports Go development with the go-plus package.

To use Delve inside Atom, install the go-debug package.

To run your Go code in Atom, install the atom-runner package.

6. Links

A Tour of Go

How to Write Go Code

Effective Go

Source code: The Go Programming Language

YouTube: Concurrency is not Parallelism by Rob Pike

YouTube: Go Proverbs

7. Rights

All exercises from The Go Programming Language are copyright 2016 Alan A. A. Donovan & Brian W. Kernighan and included with permission from the authors.

All submitted code is covered under Apache License 2.0.