update.go

// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) 2022, Unikraft GmbH and The KraftKit Authors.
// Licensed under the BSD-3-Clause License (the "License").
// You may not use this file except in compliance with the License.
package update

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"kraftkit.sh/config"
	"kraftkit.sh/internal/version"
	"kraftkit.sh/iostreams"

	"github.com/MakeNowJust/heredoc"
	"github.com/Masterminds/semver/v3"
	"github.com/sirupsen/logrus"
	"kraftkit.sh/log"
)

const KraftKitLatestPath = "https://get.kraftkit.sh/latest.txt"

func Check(ctx context.Context) error {
	if version.Version() == "" {
		return nil
	}

	localCheckPath := filepath.Join(config.DataDir(), "latest.txt")
	file, err := os.OpenFile(localCheckPath, os.O_RDONLY|os.O_CREATE, 0o644)
	if err != nil {
		return err
	}
	defer file.Close()

	info, err := file.Stat()
	if err != nil {
		return err
	}

	contents, err := io.ReadAll(file)
	if err != nil {
		return err
	}

	// TODO(nderjung): Decide on a proper time frame
	if info.ModTime().Add(time.Hour).After(time.Now()) && len(contents) > 0 {
		latestVer, err := semver.NewVersion(strings.Split(string(contents), "-")[0])
		if err != nil {
			return err
		}

		currentVer, err := semver.NewVersion(strings.Split(version.Version(), "-")[0])
		if err != nil {
			return err
		}

		if currentVer.LessThan(latestVer) {
			fmt.Fprint(iostreams.G(ctx).Out, heredoc.Docf(`A new version of KraftKit is now available (v%s)!

Please update KraftKit through your local package manager or run:

curl --proto '=https' --tlsv1.2 -sSf https://get.kraftkit.sh | sh

Read the full changelog:

https://github.com/unikraft/kraftkit/releases/tag/v%s

To turn off this check, set:

export KRAFTKIT_NO_CHECK_UPDATES=true

Or use the globally accessible flag '--no-check-updates'.

		`,
				string(contents), string(contents)))
		}

		return nil
	}

	go func() {
		client := &http.Client{}

		get, err := http.NewRequest("GET", KraftKitLatestPath, nil)
		if err != nil {
			return
		}

		get.Header.Set("User-Agent", version.Version())
		log.G(ctx).WithFields(logrus.Fields{
			"url":    KraftKitLatestPath,
			"method": "GET",
		}).Trace("http")

		resp, err := client.Do(get)
		if err != nil {
			return
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			return
		}

		contents, err := io.ReadAll(resp.Body)
		if err != nil {
			return
		}

		file, err := os.OpenFile(localCheckPath, os.O_WRONLY|os.O_CREATE|os.O_SYNC|os.O_TRUNC, 0o644)
		if err != nil {
			return
		}
		_, err = file.Write(contents)
		if err != nil {
			return
		}
		file.Close()
	}()

	return nil
}