Sendmail command (#13079)

* Add SendSync method

Usefull to have when you need to be confident that message was sent.

* Add sendmail command

* add checks that if either title or content is empty then error out

* Add a confirmation step

* Add --force option to bypass confirm step

* Move implementation of runSendMail to a different file

* Add copyrighting comment

* Make content optional

Print waring if it's empty or haven't been set up.
The warning will be skiped if there's a `--force` flag.

* Fix import style

Co-authored-by: 6543 <6543@obermui.de>

* Use batch when getting all users

IterateUsers uses batching by default.

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Send emails one by one instead of as one chunck

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Send messages concurantly

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Use SendAsync+Flush instead of SendSync

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Add timeout parameter to sendemail command

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Fix spelling mistake

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

* Update cmd/admin.go

Co-authored-by: 6543 <6543@obermui.de>

* Connect to a running Gitea instance

* Fix mispelling

* Add copyright comment

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

cmd/admin.go

@@ -34,6 +34,7 @@ var (
 			subcmdRepoSyncReleases,
 			subcmdRegenerate,
 			subcmdAuth,
+			subcmdSendMail,
 		},
 	}
 
@@ -282,6 +283,28 @@ var (
 		Action: runAddOauth,
 		Flags:  oauthCLIFlags,
 	}
+
+	subcmdSendMail = cli.Command{
+		Name:   "sendmail",
+		Usage:  "Send a message to all users",
+		Action: runSendMail,
+		Flags: []cli.Flag{
+			cli.StringFlag{
+				Name:  "title",
+				Usage: `a title of a message`,
+				Value: "",
+			},
+			cli.StringFlag{
+				Name:  "content",
+				Usage: "a content of a message",
+				Value: "",
+			},
+			cli.BoolFlag{
+				Name:  "force,f",
+				Usage: "A flag to bypass a confirmation step",
+			},
+		},
+	}
 )
 
 func runChangePassword(c *cli.Context) error {

cmd/cmd.go

@@ -9,6 +9,7 @@ package cmd
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/setting"
@@ -32,6 +33,25 @@ func argsSet(c *cli.Context, args ...string) error {
 	return nil
 }
 
+// confirm waits for user input which confirms an action
+func confirm() (bool, error) {
+	var response string
+
+	_, err := fmt.Scanln(&response)
+	if err != nil {
+		return false, err
+	}
+
+	switch strings.ToLower(response) {
+	case "y", "yes":
+		return true, nil
+	case "n", "no":
+		return false, nil
+	default:
+		return false, errors.New(response + " isn't a correct confirmation string")
+	}
+}
+
 func initDB() error {
 	return initDBDisableConsole(false)
 }

cmd/mailer.go

@@ -0,0 +1,48 @@
+// 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 cmd
+
+import (
+	"fmt"
+	"net/http"
+
+	"code.gitea.io/gitea/modules/private"
+	"github.com/urfave/cli"
+)
+
+func runSendMail(c *cli.Context) error {
+	if err := argsSet(c, "title"); err != nil {
+		return err
+	}
+
+	subject := c.String("title")
+	confirmSkiped := c.Bool("force")
+	body := c.String("content")
+
+	if !confirmSkiped {
+		if len(body) == 0 {
+			fmt.Print("warning: Content is empty")
+		}
+
+		fmt.Print("Proceed with sending email? [Y/n] ")
+		isConfirmed, err := confirm()
+		if err != nil {
+			return err
+		} else if !isConfirmed {
+			fmt.Println("The mail was not sent")
+			return nil
+		}
+	}
+
+	status, message := private.SendEmail(subject, body, nil)
+	if status != http.StatusOK {
+		fmt.Printf("error: %s", message)
+		return nil
+	}
+
+	fmt.Printf("Succseded: %s", message)
+
+	return nil
+}