Add Matrix Notifier

config/config.go

@@ -439,6 +439,7 @@ type Receiver struct {
 	OpsGenieConfigs  []*OpsGenieConfig  `yaml:"opsgenie_configs,omitempty" json:"opsgenie_configs,omitempty"`
 	PushoverConfigs  []*PushoverConfig  `yaml:"pushover_configs,omitempty" json:"pushover_configs,omitempty"`
 	VictorOpsConfigs []*VictorOpsConfig `yaml:"victorops_configs,omitempty" json:"victorops_configs,omitempty"`
+	MatrixConfigs    []*MatrixConfig    `yaml:"matrix_configs,omitempty" json:"matrix_configs,omitempty"`
 
 	// Catches all undefined fields and must be empty after parsing.
 	XXX map[string]interface{} `yaml:",inline" json:"-"`

config/notifiers.go

@@ -115,6 +115,14 @@ var (
 		Retry:    duration(1 * time.Minute),
 		Expire:   duration(1 * time.Hour),
 	}
+
+	DefaultMatrixConfig = MatrixConfig{
+		NotifierConfig: NotifierConfig{
+			VSendResolved: false,
+		},
+		Text: `{{ template "matrix.default.text" . }}`,
+		HTML: `{{ template "matrix.default.html" . }}`,
+	}
 )
 
 // NotifierConfig contains base options common across all notifier configurations.
@@ -231,6 +239,37 @@ func (c *SlackConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return checkOverflow(c.XXX, "slack config")
 }
 
+type MatrixConfig struct {
+	NotifierConfig `yaml:",inline" json:",inline"`
+
+	AccessToken string `yaml:"access_token" json:"access_token"`
+	RoomID      string `yaml:"room_id" json:"room_id"`
+
+	Text string `yaml:"text" json:"text"`
+	HTML string `yaml:"html" json:"html"`
+
+	// Catches all undefined fields and must be empty after parsing.
+	XXX map[string]interface{} `yaml:",inline" json:"-"`
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (c *MatrixConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	*c = DefaultMatrixConfig
+	type plain MatrixConfig
+	if err := unmarshal((*plain)(c)); err != nil {
+		return err
+	}
+	if c.RoomID == "" {
+		return fmt.Errorf("missing room id in Matrix config")
+	}
+
+	if c.AccessToken == "" {
+		return fmt.Errorf("missing access token in Matrix config")
+	}
+
+	return checkOverflow(c.XXX, "matrix config")
+}
+
 // HipchatConfig configures notifications via Hipchat.
 type HipchatConfig struct {
 	NotifierConfig `yaml:",inline" json:",inline"`

doc/examples/simple.yml

@@ -121,3 +121,9 @@ receivers:
     room_id: 85
     message_format: html
     notify: true
+- name: 'matrix'
+  matrix_configs:
+  - access_token: <access_token>
+    room_id: !<something>:matrix.org
+    text: "text msg"
+    html: "html msg"

notify/impl.go

@@ -130,6 +130,10 @@ func BuildReceiverIntegrations(nc *config.Receiver, tmpl *template.Template) []I
 		n := NewPushover(c, tmpl)
 		add("pushover", i, n, c)
 	}
+	for i, c := range nc.MatrixConfigs {
+		n := NewMatrix(c, tmpl)
+		add("matrix", i, n, c)
+	}
 	return integrations
 }
 
@@ -543,6 +547,77 @@ func (n *Slack) retry(statusCode int) (bool, error) {
 	return false, nil
 }
 
+// matrixEvent is the event for sending a matrix notification.
+type matrixEvent struct {
+	MsgType       string `json:"msgtype"`
+	Body          string `json:"body"`
+	FormattedBody string `json:"formatted_body,omitempty"`
+	Format        string `json:"format,omitempty"`
+}
+
+// Matrix implements a Notifier for Matrix notifications.
+type Matrix struct {
+	conf *config.MatrixConfig
+	tmpl *template.Template
+}
+
+// NewMatrix returns a new Matrix notification handler.
+func NewMatrix(conf *config.MatrixConfig, tmpl *template.Template) *Matrix {
+	return &Matrix{
+		conf: conf,
+		tmpl: tmpl,
+	}
+}
+
+// Notify implements the Notifier interface.
+func (n *Matrix) Notify(ctx context.Context, as ...*types.Alert) (bool, error) {
+	var err error
+	var (
+		data     = n.tmpl.Data(receiverName(ctx), groupLabels(ctx), as...)
+		tmplText = tmplText(n.tmpl, data, &err)
+		tmplHTML = tmplHTML(n.tmpl, data, &err)
+		url      = fmt.Sprintf("https://matrix.org/_matrix/client/r0/rooms/%s/send/m.room.message/m%d.1?access_token=%s", n.conf.RoomID, time.Now().Unix(), n.conf.AccessToken)
+	)
+
+	event := &matrixEvent{
+		MsgType:       "m.text",
+		Body:          tmplText(n.conf.Text),
+		FormattedBody: tmplHTML(n.conf.HTML),
+	}
+	if event.FormattedBody != "" {
+		event.Format = "org.matrix.custom.html"
+	}
+
+	var buf bytes.Buffer
+	if err := json.NewEncoder(&buf).Encode(event); err != nil {
+		return false, err
+	}
+
+	req, errNew := http.NewRequest("PUT", url, &buf)
+	if errNew != nil {
+		return false, errNew
+	}
+
+	resp, err := ctxhttp.Do(ctx, http.DefaultClient, req)
+	if err != nil {
+		return true, err
+	}
+	defer resp.Body.Close()
+
+	return n.retry(resp.StatusCode)
+}
+
+func (n *Matrix) retry(statusCode int) (bool, error) {
+	// Matrix responds with a 200 response code on a successful
+	// request and 5xx response codes are assumed to be recoverable.
+	// http://matrix.org/docs/spec/client_server/r0.2.0.html#put-matrix-client-r0-rooms-roomid-send-eventtype-txnid
+	if statusCode != 200 {
+		return (statusCode/100 == 5), fmt.Errorf("unexpected status code %v", statusCode)
+	}
+
+	return false, nil
+}
+
 // Hipchat implements a Notifier for Hipchat notifications.
 type Hipchat struct {
 	conf *config.HipchatConfig

template/default.tmpl

@@ -26,6 +26,11 @@
 {{ define "hipchat.default.message" }}{{ template "__subject" . }}{{ end }}
 
 
+{{ define "matrix.default.text" }}{{ template "__subject" . }}
+{{ template "__alertmanagerURL" . }}{{ end }}
+{{ define "matrix.default.html" }}<a href="{{ template "__alertmanagerURL" . }}"><font color="{{ if eq .Status "firing" }}red{{ else }}green{{ end }}"><b>{{ template "__subject" . }}</b></font></a>{{ end }}
+
+
 {{ define "pagerduty.default.description" }}{{ template "__subject" . }}{{ end }}
 {{ define "pagerduty.default.client" }}{{ template "__alertmanager" . }}{{ end }}
 {{ define "pagerduty.default.clientURL" }}{{ template "__alertmanagerURL" . }}{{ end }}