listmonk/cmd/updates.go
Kailash Nadh d8a60d1295 Add automatic update checks.
- A check for new versions on the GitHub releases pages happens
  once every 24 hours. When a new version is available, a notice
  is displayed on the admin UI.
2020-08-08 16:59:47 +05:30

78 lines
1.9 KiB
Go

package main
import (
"encoding/json"
"io/ioutil"
"net/http"
"regexp"
"time"
"golang.org/x/mod/semver"
)
const updateCheckURL = "https://api.github.com/repos/knadh/listmonk/releases/latest"
type remoteUpdateResp struct {
Version string `json:"tag_name"`
URL string `json:"html_url"`
}
// AppUpdate contains information of a new update available to the app that
// is sent to the frontend.
type AppUpdate struct {
Version string `json:"version"`
URL string `json:"url"`
}
var reSemver = regexp.MustCompile(`-(.*)`)
// checkUpdates is a blocking function that checks for updates to the app
// at the given intervals. On detecting a new update (new semver), it
// sets the global update status that renders a prompt on the UI.
func checkUpdates(curVersion string, interval time.Duration, app *App) {
// Strip -* suffix.
curVersion = reSemver.ReplaceAllString(curVersion, "")
time.Sleep(time.Second * 1)
ticker := time.NewTicker(interval)
for ; true; <-ticker.C {
resp, err := http.Get(updateCheckURL)
if err != nil {
app.log.Printf("error checking for remote update: %v", err)
continue
}
if resp.StatusCode != 200 {
app.log.Printf("non 200 response on remote update check: %d", resp.StatusCode)
continue
}
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
app.log.Printf("error reading remote update payload: %v", err)
continue
}
resp.Body.Close()
var up remoteUpdateResp
if err := json.Unmarshal(b, &up); err != nil {
app.log.Printf("error unmarshalling remote update payload: %v", err)
continue
}
// There is an update. Set it on the global app state.
if semver.IsValid(up.Version) {
v := reSemver.ReplaceAllString(up.Version, "")
if semver.Compare(v, curVersion) > 0 {
app.Lock()
app.update = &AppUpdate{
Version: up.Version,
URL: up.URL,
}
app.Unlock()
app.log.Printf("new update %s found", up.Version)
}
}
}
}