[WIP] Add matrix alerter

alert/matrix.go

@@ -0,0 +1,56 @@
+package alert
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	blackfriday "gopkg.in/russross/blackfriday.v2"
+)
+
+// Matrix alert container.
+type Matrix struct {
+	client *http.Client
+	token  string
+	room   string
+}
+
+// NewMatrix returns a Matrix alerter from the private token
+// and the room identifier, both available in the Riot web UI.
+func NewMatrix(token string, room string) *Matrix {
+	return &Matrix{
+		client: &http.Client{},
+		token:  token,
+		room:   room,
+	}
+}
+
+// Alert sends a message to the matrix room.
+func (p *Matrix) Alert(title, body string) {
+	data := "☢️ **" + title + "**: " + body
+	markdownBody := blackfriday.Run(
+		[]byte(data),
+		blackfriday.WithExtensions(blackfriday.HardLineBreak|blackfriday.NoEmptyLineBeforeBlock),
+	)
+	raw, _ := json.Marshal(map[string]string{
+		"msgtype":        "m.text",
+		"format":         "org.matrix.custom.html",
+		"formatted_body": string(markdownBody),
+		"body":           data,
+	})
+
+	url := fmt.Sprintf(
+		"https://matrix.org/_matrix/client/r0/rooms/%s/send/m.room.message/%d?access_token=%s",
+		url.PathEscape(p.room),
+		time.Now().UnixNano(),
+		p.token,
+	)
+
+	req, _ := http.NewRequest("PUT", url, bytes.NewReader(raw))
+	req.Header.Set("Content-Type", "application/json")
+
+	_, _ = p.client.Do(req)
+}

config.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/Lesterpig/board/alert"
 	"github.com/Lesterpig/board/probe"
-
 	"github.com/spf13/viper"
 )
 
@@ -20,6 +19,7 @@ type serviceConfig struct {
 type alertConfig struct {
 	Type  string
 	Token string
+	Dest  string
 }
 
 var probeConstructors = map[string](func() probe.Prober){
@@ -34,6 +34,9 @@ var alertConstructors = map[string](func(c alertConfig) alert.Alerter){
 	"pushbullet": func(c alertConfig) alert.Alerter {
 		return alert.NewPushbullet(c.Token)
 	},
+	"matrix": func(c alertConfig) alert.Alerter {
+		return alert.NewMatrix(c.Token, c.Dest)
+	},
 }
 
 var alerters []alert.Alerter

example.yaml

@@ -18,4 +18,7 @@ services:
 alerts:
   - type: pushbullet
     token: <your token here>
+  - type: matrix
+    token: <emitter private token>
+    dest: <room identifier>
   # ...