Go SDK

Installation

go get github.com/vexil-platform/vexil/sdks/go/vexil

Quick Start

package main

import (
    "fmt"
    "github.com/vexil-platform/vexil/sdks/go/vexil"
)

func main() {
    // From environment variables
    client, err := vexil.New(vexil.WithEnvProvider())
    if err != nil {
        panic(err)
    }
    defer client.Close()

    darkMode := client.Bool("dark-mode", false)
    rateLimit := client.Int("api-rate-limit", 100)
    banner := client.String("banner-text", "Welcome")

    fmt.Printf("dark-mode=%v rate-limit=%d banner=%q\n",
        darkMode, rateLimit, banner)
}

Providers

Environment Variables

client, _ := vexil.New(vexil.WithEnvProvider())

Reads flags from FLAG_* environment variables. The flag name is converted to uppercase with hyphens replaced by underscores: dark-mode becomes FLAG_DARK_MODE.

Sidecar

client, _ := vexil.New(vexil.WithSidecarProvider("http://localhost:8514"))

Fetches flags from the Vexil sidecar HTTP API.

ConfigMap

client, _ := vexil.New(vexil.WithConfigMapProvider("/etc/vexil"))

Reads flags from files in the mounted ConfigMap directory.

API

Client Methods

Method	Signature	Description
Bool	Bool(name string, defaultVal bool) bool	Get boolean flag
String	String(name string, defaultVal string) string	Get string flag
Int	Int(name string, defaultVal int) int	Get integer flag
JSON	JSON(name string, dst interface{}) error	Unmarshal JSON flag
Flag	Flag(name string) (Flag, error)	Get raw flag struct
AllFlags	AllFlags() ([]Flag, error)	List all flags
Close	Close() error	Clean up resources

Flag Struct

type Flag struct {
    Name     string
    Type     string   // "boolean", "string", "integer", "json"
    Value    string
    Disabled bool
}

Provider Interface

Implement this to create custom providers:

type Provider interface {
    GetFlag(name string) (Flag, error)
    GetAllFlags() ([]Flag, error)
    Close() error
}