Add support for auxiliary message file (#81)

* Add support for external message loaded from the file specified in Config.MessageFile

* Enable the message file option in command line/env vars

* Update docs

* Add a testcase

* Fix YAML tag in DOCS.md from 'messageFile' to 'message_file', as is commonly used in Drone

* Remove unintended blank line

* Move .test.message file to tests/ folder

DOCS.md

@@ -149,6 +149,16 @@ Example configuration with a custom message template:
 +       {{/success}}
 ```
 
+Example configuration with a custom message template loaded from file:
+
+```diff
+  image: appleboy/drone-telegram
+  settings:
+    token: xxxxxxxxxx
+    to: telegram_user_id
++   message_file: message_file.tpl
+```
+
 ## Parameter Reference
 
 token
@@ -160,6 +170,9 @@ to
 message
 : overwrite the default message template
 
+message_file
+: overwrite the default message template with the contents of the specified file
+
 photo
 : local file path
 

README.md

@@ -69,6 +69,7 @@ docker run --rm \
   -e PLUGIN_TOKEN=xxxxxxx \
   -e PLUGIN_TO=xxxxxxx \
   -e PLUGIN_MESSAGE=test \
+  -e PLUGIN_MESSAGE_FILE=testmessage.md \  
   -e PLUGIN_PHOTO=tests/github.png \
   -e PLUGIN_DOCUMENT=tests/gophercolor.png \
   -e PLUGIN_STICKER=tests/github-logo.png \

main.go

@@ -36,6 +36,11 @@ func main() {
 			Usage:  "send telegram message",
 			EnvVar: "PLUGIN_MESSAGE,TELEGRAM_MESSAGE,INPUT_MESSAGE",
 		},
+		cli.StringFlag{
+			Name:   "message.file",
+			Usage:  "send telegram message from file",
+			EnvVar: "PLUGIN_MESSAGE_FILE,TELEGRAM_MESSAGE_FILE,INPUT_MESSAGE_FILE",
+		},
 		cli.StringSliceFlag{
 			Name:   "photo",
 			Usage:  "send photo message",
@@ -288,6 +293,7 @@ func run(c *cli.Context) error {
 			WebPreview:  c.Bool("webpage.preview"),
 			To:          c.StringSlice("to"),
 			Message:     c.StringSlice("message"),
+			MessageFile: c.String("message.file"),
 			Photo:       c.StringSlice("photo"),
 			Document:    c.StringSlice("document"),
 			Sticker:     c.StringSlice("sticker"),

plugin.go

@@ -1,9 +1,12 @@
 package main
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"log"
+	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -62,6 +65,7 @@ type (
 		WebPreview  bool
 		To          []string
 		Message     []string
+		MessageFile string
 		Photo       []string
 		Document    []string
 		Sticker     []string
@@ -184,6 +188,20 @@ func convertLocation(value string) (Location, bool) {
 	}, false
 }
 
+func loadTextFromFile(filename string) ([]string, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	r := bufio.NewReader(f)
+	content, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	return []string{string(content)}, nil
+}
+
 func parseTo(to []string, authorEmail string, matchEmail bool) []int64 {
 	var emails []int64
 	var ids []int64
@@ -222,22 +240,26 @@ func parseTo(to []string, authorEmail string, matchEmail bool) []int64 {
 }
 
 // Exec executes the plugin.
-func (p Plugin) Exec() error {
+func (p Plugin) Exec() (err error) {
-
 	if len(p.Config.Token) == 0 || len(p.Config.To) == 0 {
 		return errors.New("missing telegram token or user list")
 	}
 
 	var message []string
-	if len(p.Config.Message) > 0 {
+	switch {
+	case len(p.Config.MessageFile) > 0:
+		message, err = loadTextFromFile(p.Config.MessageFile)
+		if err != nil {
+			return fmt.Errorf("error loading message file '%s': %v", p.Config.MessageFile, err)
+		}
+	case len(p.Config.Message) > 0:
 		message = p.Config.Message
-	} else {
+	default:
 		message = p.Message()
 	}
 
-	bot, err := tgbotapi.NewBotAPI(p.Config.Token)
+	var bot *tgbotapi.BotAPI
-
+	if bot, err = tgbotapi.NewBotAPI(p.Config.Token); err != nil {
-	if err != nil {
 		return err
 	}
 

plugin_test.go

@@ -325,3 +325,32 @@ func TestHTMLMessage(t *testing.T) {
 	err := plugin.Exec()
 	assert.Nil(t, err)
 }
+
+func TestMessageFile(t *testing.T) {
+	plugin := Plugin{
+		Repo: Repo{
+			Name:      "go-hello",
+			Namespace: "appleboy",
+		},
+		Commit: Commit{
+			Sha:     "e7c4f0a63ceeb42a39ac7806f7b51f3f0d204fd2",
+			Author:  "Bo-Yi Wu",
+			Branch:  "master",
+			Message: "Freakin' macOS isn't fully case-sensitive..",
+		},
+		Build: Build{
+			Number: 101,
+			Status: "success",
+			Link:   "https://github.com/appleboy/go-hello",
+		},
+
+		Config: Config{
+			Token:       os.Getenv("TELEGRAM_TOKEN"),
+			To:          []string{os.Getenv("TELEGRAM_TO")},
+			MessageFile: "tests/.test.message",
+		},
+	}
+
+	err := plugin.Exec()
+	assert.Nil(t, err)
+}

tests/.test.message

@@ -0,0 +1,4 @@
+Sample message loaded from file.
+
+Commit msg:  {{commit.message}}
+