l0nax/changelog-go

package internal

import (
    "encoding/json"
    "net/http"
    "runtime"
    "strings"
    "time"
)

type versionInfo struct {
    Version string `json:"Version"`
    Sha256  string `json:"Sha256"`
}

// CheckUpdate will check if there is a new update available.
// If so it will return 'true'.
func CheckUpdate(version, dataURL string) bool {
    // initialize HTTP Client
    client := http.Client{
        // max 500ms timeout, to not slow the application too much down
        Timeout: time.Millisecond * 500,
    }

    // prepare API URL
    url := dataURL + "/" + runtime.GOOS + "-" + runtime.GOARCH + ".json"

    req, err := http.NewRequest(http.MethodGet, url, nil)
    if err != nil {
        // NOTE(l0nax): Do not print an error when the update check fails.
        // ilog.Log.WithError(err).Errorln("could not initialize http requester")
        return false
    }

    req.Header.Set("User-Agent", "changelog-go/"+version)

    res, err := client.Do(req)
    if err != nil {
        // NOTE(l0nax): Do not print an error when the update check fails.
        // ilog.Log.Errorln(err)
        return false
    }

    if res.Body != nil {
        defer res.Body.Close()
    }

    info := new(versionInfo)

    // marshal response body into versionInfo struct
    _ = json.NewDecoder(res.Body).Decode(info)

    // remove 'v' prefix from any versions
    info.Version = strings.TrimPrefix(info.Version, "v")
    version = strings.TrimPrefix(version, "v")

    // no update found
    return version != info.Version
}