main.go

package main

import (
	"context"
	"database/sql"
	"flag"
	"log"
	"os"
	"os/signal"
	"syscall"
	"time"

	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"

	_ "github.com/go-sql-driver/mysql"
)

var (
	masterURL  string
	kubeconfig string
)

func main() {
	var kubeconfig string
	flag.StringVar(&kubeconfig, "kubeconfig", "", "Path to a kubeconfig. Only required if out-of-cluster.")

	var masterURL string
	flag.StringVar(&masterURL, "master", "", "The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.")

	var dsn string
	flag.StringVar(&dsn, "dsn", "", "The DSN used to connect to MySQL")

	flag.Parse()

	cfg, err := clientcmd.BuildConfigFromFlags(masterURL, kubeconfig)
	if err != nil {
		log.Fatalf("Error building Kubernetes config: %v", err)
	}

	client, err := rest.HTTPClientFor(cfg)
	if err != nil {
		log.Fatalf("Error building Kubernetes client: %v", err)
	}

	db, err := sql.Open("mysql", dsn)
	if err == nil {
		db.SetConnMaxLifetime(time.Minute * 3)
		db.SetMaxOpenConns(1)
		db.SetMaxIdleConns(1)
		err = db.Ping()
	}
	if err != nil {
		log.Fatalf("Error connecting to MySQL: %v", err)
	}

	c := make(chan os.Signal, 2)
	ctx, cancel := context.WithCancel(context.Background())
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
	go func() {
		// Cancel on first signal.
		<-c
		cancel()
		// Force quit on second signal.
		<-c
		os.Exit(1)
	}()

	NewController(cfg, client, db).Run(ctx)
}