Add email notify for new release (#12463)

* Add email notify for new release

Signed-off-by: a1012112796 <1012112796@qq.com>

services/mailer/mail_release.go

@@ -0,0 +1,69 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package mailer
+
+import (
+	"bytes"
+	"fmt"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/markup/markdown"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+const (
+	tplNewReleaseMail base.TplName = "release"
+)
+
+// MailNewRelease send new release notify to all all repo watchers.
+func MailNewRelease(rel *models.Release) {
+	watcherIDList, err := models.GetRepoWatchersIDs(rel.RepoID)
+	if err != nil {
+		log.Error("GetRepoWatchersIDs(%d): %v", rel.RepoID, err)
+		return
+	}
+
+	recipients, err := models.GetMaileableUsersByIDs(watcherIDList)
+	if err != nil {
+		log.Error("models.GetMaileableUsersByIDs: %v", err)
+		return
+	}
+
+	tos := make([]string, 0, len(recipients))
+	for _, to := range recipients {
+		if to.ID != rel.PublisherID {
+			tos = append(tos, to.Email)
+		}
+	}
+
+	rel.RenderedNote = markdown.RenderString(rel.Note, rel.Repo.Link(), rel.Repo.ComposeMetas())
+	subject := fmt.Sprintf("%s in %s released", rel.TagName, rel.Repo.FullName())
+
+	mailMeta := map[string]interface{}{
+		"Release": rel,
+		"Subject": subject,
+	}
+
+	var mailBody bytes.Buffer
+
+	if err = bodyTemplates.ExecuteTemplate(&mailBody, string(tplNewReleaseMail), mailMeta); err != nil {
+		log.Error("ExecuteTemplate [%s]: %v", string(tplNewReleaseMail)+"/body", err)
+		return
+	}
+
+	msgs := make([]*Message, 0, len(recipients))
+	publisherName := rel.Publisher.DisplayName()
+	relURL := "<" + rel.HTMLURL() + ">"
+	for _, to := range tos {
+		msg := NewMessageFrom([]string{to}, publisherName, setting.MailService.FromEmail, subject, mailBody.String())
+		msg.Info = subject
+		msg.SetHeader("Message-ID", relURL)
+		msgs = append(msgs, msg)
+	}
+
+	SendAsyncs(msgs)
+}