backup/admin.go

package main

import (
	"context"
	"net/http"
	"os/signal"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/robfig/cron/v3"
	"github.com/sethvargo/go-password/password"
	log "github.com/sirupsen/logrus"
)

type AdminConfig struct {
	Users   []User        `json:"users"`
	Secrets SecretsConfig `json:"secrets"`
	Addr    string        `json:"addr"`
}

type SecretsConfig struct {
	PasswordPepper    string `json:"password_pepper"`
	ContextKey        string `json:"context_key"`
	ContextExpiration int    `json:"context_expiration"`
	ScryptN           int    `json:"scrypt_n"`
	ScryptR           int    `json:"scrypt_r"`
	ScryptP           int    `json:"scrypt_p"`
}

func NewAdmin() *AdminConfig {
	pepper, _ := password.Generate(20, 5, 0, false, false)
	ctx, _ := password.Generate(20, 5, 0, false, false)

	a := &AdminConfig{
		Addr: "0.0.0.0:8080",
		Secrets: SecretsConfig{
			PasswordPepper:    pepper,
			ContextKey:        ctx,
			ContextExpiration: 3600,
			ScryptN:           32768,
			ScryptR:           8,
			ScryptP:           1,
		},
		Users: make([]User, 0),
	}

	return a
}

func (a *AdminConfig) Run() {
	log.WithFields(log.Fields{}).Debugf("starting")
	defer log.WithFields(log.Fields{}).Debugf("done")

	// Create context that listens for the interrupt signal from the OS.
	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	if !*debug {
		gin.SetMode(gin.ReleaseMode)
	}

	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"message": "pong",
		})
	})

	srv := &http.Server{
		Addr:    a.Addr,
		Handler: r,
	}

	go func() {
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.WithFields(log.Fields{"call": "http.ListenAndServe", "attr": a.Addr, "error": err}).Errorf("")
		}
	}()

	c := cron.New(cron.WithLocation(time.UTC))
	c.AddFunc("00 * * *", func() { cfg.Run() })

	// Listen for the interrupt signal.
	<-ctx.Done()

	// Restore default behavior on the interrupt signal and notify user of shutdown.
	stop()
	log.WithFields(log.Fields{"call": "stop"}).Warnf("shutting down")

	// The context is used to inform the server it has 5 seconds to finish
	// the request it is currently handling
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := srv.Shutdown(ctx); err != nil {
		log.WithFields(log.Fields{"call": "http.Shutdown", "error": err}).Errorf("shutting down")
	}

}