Why build tags

When releasing application binaries to customers, if we need to control features based on our plans like "Free, Pro, and Enterprise levels", build tags can help.

go build

go build filename.go
    It will create filename.exe
go build
    It will create folder.exe, with all go files in that folder, build within it.

build Tag Syntax

In first line of the go program, write in below synatx.

// +build tag_name

NOTE: ensure to leave an empty line after the build tag line.

when building the binary, pass the corresponding tag(s) name(s).

go build -tags TAGNAME

build Tag boolean logic

We can have more than one build tags.

Build Tag Syntax	Build Tag Sample	Boolean Statement
Space-separated elements	// +build pro enterprise	pro OR enterprise
Comma-separated elements	// +build pro,enterprise	pro AND enterprise
Exclamation point elements	// +build !pro	NOT pro

Ref: https://www.digitalocean.com/community/tutorials/customizing-go-binaries-with-build-tags

project Usage

~go build

~ls
a-buildtag-features-app.exe  enterprise.go  main.go  pro.go  README.md

~a-buildtag-features-app.exe
> Free Feature #1
> Free Feature #2

~go build -tags pro

~a-buildtag-features-app.exe
> Free Feature #1
> Free Feature #2
> Pro Feature #1 
> Pro Feature #2 

~go build -tags enterprise

~a-buildtag-features-app.exe
> Free Feature #1
> Free Feature #2

~go build -tags "pro enterprise"

~a-buildtag-features-app.exe     
> Free Feature #1
> Free Feature #2
> Enterprise Feature #1
> Enterprise Feature #2
> Pro Feature #1
> Pro Feature #2