add SlackNotifier

README.md

@@ -42,6 +42,7 @@ Run `osem_notify help config` for details and an example configuration.
 `transport` | `options`
 ------------|------------
 `email`     | `recipients`: list of email addresses
+`slack`     | -
 `xmpp`      | `recipients`: list of JIDs
 
 Want more? [add it](#contribute)!

cmd/cmd_root.go

@@ -59,6 +59,10 @@ var configHelpCmd = &cobra.Command{
     pass: bar
     from: hildegunst@example.com
 
+  # only needed when sending notifications via Slack
+  slack:
+    webhook: https://hooks.slack.com/services/T030YPW07/xxxxxxx/xxxxxxxxxxxxxxxxxxxxxx
+
   # only needed when sending notifications via XMPP
   xmpp:
     host: jabber.example.com:5222
@@ -72,6 +76,7 @@ var configHelpCmd = &cobra.Command{
   transport | options
   ----------|-------------------------------------
   email     | recipients: list of email addresses
+  slack     | -
   xmpp      | recipients: list of JIDs
 
 

core/notifier_slack.go

@@ -0,0 +1,73 @@
+package core
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/dghubble/sling"
+	"github.com/spf13/viper"
+)
+
+var slackClient = sling.New().Client(&http.Client{})
+
+var notificationColors = map[string]string {
+	CheckOk: "#00ff00",
+	CheckErr: "#ff0000",
+}
+
+// slack Notifier has no configuration
+type SlackNotifier struct {
+	webhook string
+}
+
+type SlackMessage struct {
+	Text        string            `json:"text"`
+	Username    string            `json:"username,omitempty`
+	Attachments []SlackAttachment `json:"attachments,omitempty"`
+}
+
+type SlackAttachment struct {
+	Text  string `json:"text"`
+	Color string `json:"color,omitempty"`
+}
+
+func (n SlackNotifier) New(config TransportConfig) (AbstractNotifier, error) {
+	// validate transport configuration
+	// :TransportConfSourceHack
+	baseUrl := viper.GetString("slack.webhook")
+	if baseUrl == "" {
+		return nil, fmt.Errorf("Missing configuration key slack.webhook")
+	}
+
+	return SlackNotifier{
+		webhook: baseUrl,
+	}, nil
+}
+
+func (n SlackNotifier) Submit(notification Notification) error {
+	message := &SlackMessage{
+		Username: "osem_notify box healthcheck",
+		Text:        notification.Subject,
+		Attachments: []SlackAttachment{ { notification.Body, notificationColors[notification.Status] } },
+	}
+
+	req, err := slackClient.Post(n.webhook).BodyJSON(message).Request()
+	if err != nil {
+		return err
+	}
+
+	c := http.Client{}
+	res, err2 := c.Do(req)
+	if err2 != nil {
+		return err2
+	}
+
+	if res.StatusCode > 200 {
+		defer res.Body.Close()
+		body, _ := ioutil.ReadAll(res.Body)
+		return fmt.Errorf("slack webhook failed: %s", body)
+	}
+
+	return nil
+}

core/notifier_xmpp.go

@@ -8,7 +8,7 @@ import (
 	"github.com/spf13/viper"
 )
 
-var client = &xmpp.Client{} // @Hacky
+var xmppClient = &xmpp.Client{} // @Hacky
 
 // box config required for the XmppNotifier (TransportConfig.Options)
 type XmppNotifier struct {
@@ -27,12 +27,12 @@ func (n XmppNotifier) New(config TransportConfig) (AbstractNotifier, error) {
 
 	// establish connection with server once, and share it accross instances
 	// @Hacky
-	if client.JID() == "" {
+	if xmppClient.JID() == "" {
 		c, err := connectXmpp()
 		if err != nil {
 			return nil, err
 		}
-		client = c
+		xmppClient = c
 	}
 
 	// assign configuration to the notifier after ensuring the correct type.
@@ -65,12 +65,12 @@ func (n XmppNotifier) New(config TransportConfig) (AbstractNotifier, error) {
 }
 
 func (n XmppNotifier) Submit(notification Notification) error {
-	if client.JID() == "" {
+	if xmppClient.JID() == "" {
 		return fmt.Errorf("xmpp client not correctly initialized!")
 	}
 
 	for _, recipient := range n.Recipients {
-		_, err := client.Send(xmpp.Chat{
+		_, err := xmppClient.Send(xmpp.Chat{
 			Remote:  recipient,
 			Subject: notification.Subject,
 			Text:    fmt.Sprintf("%s\n\n%s", notification.Subject, notification.Body),

core/notifiers.go

@@ -10,6 +10,7 @@ import (
 
 var Notifiers = map[string]AbstractNotifier{
 	"email": EmailNotifier{},
+	"slack": SlackNotifier{},
 	"xmpp":  XmppNotifier{},
 }
 
@@ -19,6 +20,7 @@ type AbstractNotifier interface {
 }
 
 type Notification struct {
+	Status  string // one of CheckOk | CheckErr
 	Body    string
 	Subject string
 }
@@ -137,17 +139,21 @@ func ComposeNotification(box *Box, checks []CheckResult) Notification {
 		resolved     string
 		resolvedList string
 		errList      string
+		status string
 	)
 	if len(resolvedTexts) != 0 {
 		resolvedList = fmt.Sprintf("Resolved issue(s):\n\n%s\n\n", strings.Join(resolvedTexts, "\n"))
 	}
 	if len(errTexts) != 0 {
 		errList = fmt.Sprintf("New issue(s):\n\n%s\n\n", strings.Join(errTexts, "\n"))
+		status = CheckErr
 	} else {
 		resolved = "resolved "
+		status = CheckOk
 	}
 
 	return Notification{
+		Status: status,
 		Subject: fmt.Sprintf("Issues %swith your box \"%s\" on opensensemap.org!", resolved, box.Name),
 		Body: fmt.Sprintf("A check at %s identified the following updates for your box \"%s\":\n\n%s%sYou may visit https://opensensemap.org/explore/%s for more details.\n\n--\nSent automatically by osem_notify (https://github.com/noerw/osem_notify)",
 			time.Now().Round(time.Minute), box.Name, errList, resolvedList, box.Id),