config.go

package main

import (
	"encoding/json"
	"io/ioutil"
	"log"

	"github.com/spf13/viper"
)

type Config struct {
	APIKey        string
	KubeHost      string
	KubePort      string
	ConsulHost    string
	ConsulPort    string
	ConsulDomain  string
	Protocol      string
	SkipTlsVerify bool
	UserConfigs   []UserConfig
}

const HTTP = "http"
const HTTPS = "https"

var appConfig *Config

func loadConfig() {
	viper.AutomaticEnv()
	viper.SetConfigName("config")
	viper.SetConfigType("yaml")
	viper.AddConfigPath(".")
	viper.ReadInConfig()

	appConfig = &Config{
		APIKey:        getKubernetesAPIToken(),
		KubeHost:      viper.GetString("KUBERNETES_SERVICE_HOST"),
		KubePort:      viper.GetString("KUBERNETES_SERVICE_PORT"),
		ConsulHost:    viper.GetString("CONSUL_HOST"),
		ConsulPort:    viper.GetString("CONSUL_PORT"),
		ConsulDomain:  viper.GetString("CONSUL_DOMAIN"),
		Protocol:      getProtocol(),
		SkipTlsVerify: viper.GetBool("SKIP_TLS_VERIFY"),
		UserConfigs:   getIngressConfigs(),
	}
}

func getProtocol() string {
	if port := viper.GetInt("KUBERNETES_SERVICE_PORT"); port == 443 {
		return HTTPS
	} else if isHttps := viper.GetBool("USE_HTTPS"); isHttps {
		return HTTPS
	} else {
		return HTTP
	}
}

func getKubernetesAPIToken() string {
	tokenFile := "/var/run/secrets/kubernetes.io/serviceaccount/token"
	data, err := ioutil.ReadFile(tokenFile)
	if err != nil {
		return viper.GetString("KUBERNETES_API_TOKEN")
	}
	return string(data)
}

func getIngressConfigs() []UserConfig {
	var configs []UserConfig

	configAsString := viper.GetString("USER_CONFIGS")
	if err := json.Unmarshal([]byte(configAsString), &configs); err != nil {
		log.Fatal(err)
	}
	return configs
}

func getConsulDomain() string {
	consulDomain := viper.GetString("CONSUL_DOMAIN")
	if consulDomain == "" {
		return "service.consul"
	}
	return consulDomain
}