feat: Add support for multiple chat rooms

A new required query param (`room_name`) is introduced in `/create` POST call.
This is for routing alerts to different teams based on the alertmanager
config.

The `room_name` must be additionally configured in `config.toml`, which
has information about `notification_url` of the room.

README.md

@@ -6,14 +6,13 @@
 
 `calert` is a lightweight binary to push [Alertmanager](https://github.com/prometheus/alertmanager) notifications to [Google Chat](http://chat.google.com) via webhook integration.
 
-
 ## Install
 
 There are various ways of installing calert.
 
 ### Precompiled binaries
 
-Precompiled binaries for released versions are available in the [*Releases* section](https://github.com/mr-karan/calert/releases/).
+Precompiled binaries for released versions are available in the [_Releases_ section](https://github.com/mr-karan/calert/releases/).
 
 ### Compiling the binary
 
@@ -29,45 +28,46 @@ $ cp config.toml.sample config.toml
 $ ./calert
 ```
 
-
 ## How to Use
 
 `calert` uses Alertmanager [webhook receiver](https://prometheus.io/docs/alerting/configuration/#webhook_config) to receive alerts payload, and pushes this data to Google Chat [webhook](https://developers.google.com/hangouts/chat/how-tos/webhooks) endpoint.
 
-- Download the binary and [sample config file](config.toml.sample) and place them in one folder.
+-   Download the binary and [sample config file](config.toml.sample) and place them in one folder.
 
 ```sh
 mkdir calert-example && cd calert-example/
 cp config.toml.sample config.toml # change the settings like hostname, address, google chat webhook url, timeouts etc in this file.
 ./calert.bin # this command starts a web server and is ready to receive events from alertmanager
 ```
 
-- Set the webhook URL from Google Chat in `[app.notification_url]` section of `config.toml`. You can refer to the [official documentation](https://developers.google.com/hangouts/chat/quickstart/incoming-bot-python#step_1_register_the_incoming_webhook) for more details.
+-   Set the webhook URL from Google Chat in `[app.notification_url]` section of `config.toml`. You can refer to the [official documentation](https://developers.google.com/hangouts/chat/quickstart/incoming-bot-python#step_1_register_the_incoming_webhook) for more details.
 
-- Configure Alertmanager config file (`alertmanager.yml`) and give the address of calert web-server. You can refer to the [official documentation](https://prometheus.io/docs/alerting/configuration/#webhook_config) for more details.
+-   Configure Alertmanager config file (`alertmanager.yml`) and give the address of calert web-server. You can refer to the [official documentation](https://prometheus.io/docs/alerting/configuration/#webhook_config) for more details.
 
 You are now ready to send alerts to Google Chat!
 
 ![](images/gchat.png)
 
 ## Configuration
 
-- You can configure the default template for notification and create your own. Create a [template](https://golang.org/pkg/text/template/) file, similar to [message.tmpl](message.tmpl) and set the path of this file in `[app.template_file]` section of `config.toml`
-
-- Alertmanager has the ability of group similar alerts together and fire only one event, clubbing all the alerts data into one event. `calert` leverages this and sends all alerts in one message by looping over the alerts and passing data in the template. You can configure the rules for grouping the alerts in `alertmanager.yml` config. You can read more about it [here](https://github.com/prometheus/docs/blob/master/content/docs/alerting/alertmanager.md#grouping)
+-   You can configure the default template for notification and create your own. Create a [template](https://golang.org/pkg/text/template/) file, similar to [message.tmpl](message.tmpl) and set the path of this file in `[app.template_file]` section of `config.toml`
 
+-   Alertmanager has the ability of group similar alerts together and fire only one event, clubbing all the alerts data into one event. `calert` leverages this and sends all alerts in one message by looping over the alerts and passing data in the template. You can configure the rules for grouping the alerts in `alertmanager.yml` config. You can read more about it [here](https://github.com/prometheus/docs/blob/master/content/docs/alerting/alertmanager.md#grouping)
 
 ## API
 
-- POST `/create` (Used to receive new alerts and push to Google Chat)
+-   POST `/create?room_name=<>` (Used to receive new alerts and push to Google Chat)
 
 ```sh
 # example request. (See examples/send_alert.sh)
-➜ curl -XPOST -d"$alerts1" http://localhost:6000/create -i
+➜ curl -XPOST -d"$alerts1" http://localhost:6000/create?room_name=<room> -i
 {"status":"success","message":"Alert sent","data":null}
 ```
 
-- GET `/ping` (Health check endpoint)
+_`room_name`_ param is required. The same `room_name` should be present in `app.chat` section. You can refer to the `config.sample` for examples.
+
+-   GET `/ping` (Health check endpoint)
+
 ```sh
 ➜ curl http://localhost:6000/ping
 {"status":"success","data":{"buildVersion":"025a3a3 (2018-12-26 22:04:46 +0530)","buildDate":"2018-12-27 10:41:52","ping":"pong"}}
@@ -83,4 +83,4 @@ PRs on Feature Requests, Bug fixes are welcome. Feel free to open an issue and h
 
 ## License
 
-[MIT](license)
+[MIT](license)

TODO.md

@@ -1,32 +1,33 @@
-- [x] Add route for inserting new alert
+-   [x] Add route for inserting new alert
 
-- [x] Parse alertmanager reponse
+-   [x] Parse alertmanager reponse
 
-- [x] Add example payload - curl script
+-   [x] Add example payload - curl script
 
-- [x] Log only errors (unix philosophy)
+-   [x] Log only errors (unix philosophy)
 
-- [x] Response check from google chat
+-   [x] Response check from google chat
 
-- [x] Gomod
+-   [x] Gomod
 
-- [x] Refactor to new name
+-   [x] Refactor to new name
 
-- [ ] Add tests
+-   [ ] Add tests
 
-- [x] Use middleware to pass around args/context/return err signature instead of naked returns (ugly! *must fix)
+-   [x] Use middleware to pass around args/context/return err signature instead of naked returns (ugly! \*must fix)
 
-- [ ] Create a package
+-   [ ] Create a package
 
-- [x] Goreleaser binary
+-   [x] Goreleaser binary
 
-- [x] Images (Google chat instructions + bot usage (gif) + Logo)
+-   [x] Images (Google chat instructions + bot usage (gif) + Logo)
 
-- [x] Add documentation + comments everywhere
+-   [x] Add documentation + comments everywhere
 
-- [x] Add License, CoC, CONTRIBUTION.md
+-   [x] Add License, CoC, CONTRIBUTION.md
 
-- [ ] Add metrics handler (feature request)
+-   [ ] Add metrics handler (feature request)
 
-- [ ] Add verbose mode (optional, low priority)
+-   [ ] Add verbose mode (optional, low priority)
 
+-   [x] Add support for chat room param, so people can use multiple chat rooms based on alertmanager config (DUH! How could I possibly miss this)

api.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 
 	alerttemplate "github.com/prometheus/alertmanager/template"
+	"github.com/spf13/viper"
 )
 
 const (
@@ -78,13 +79,25 @@ func handleNewAlert(a *App, w http.ResponseWriter, r *http.Request) (code int, m
 		alertData = alerttemplate.Data{}
 		n         = a.notifier
 	)
+	// fetch the room_name param. This room_name is used to map the webhook URL from the config.
+	// just an abstraction, for a more humanised version and to not end up making alertmanager config
+	// a mess by not flooding with google chat webhook URLs all over the place.
+	roomName := r.URL.Query().Get("room_name")
+	if roomName == "" {
+		return http.StatusBadRequest, "Missing required room_name param", nil, excepBadRequest, err
+	}
+	webHookURL := viper.GetString(fmt.Sprintf("app.chat.%s.notification_url", roomName))
+	if webHookURL == "" {
+		errMsg := fmt.Sprintf("Webhook URL not configured for room_name: %s", roomName)
+		return http.StatusBadRequest, errMsg, nil, excepBadRequest, err
+	}
 	// decode request payload from Alertmanager in a struct
 	if err := json.NewDecoder(r.Body).Decode(&alertData); err != nil {
 		errMsg := fmt.Sprintf("Error while decoding alertmanager response: %s", err)
 		return http.StatusBadRequest, errMsg, nil, excepBadRequest, err
 	}
 	// send notification to chat
-	err = sendMessageToChat(alertData.Alerts, &n)
+	err = sendMessageToChat(alertData.Alerts, &n, webHookURL)
 	if err != nil {
 		return http.StatusInternalServerError, "Something went wrong while sending alert notification", nil, excepGeneral, err
 	}

config.toml.sample

@@ -13,9 +13,14 @@ keepalive_timeout=300000
 max_body_size=20000
 
 [app]
-notification_url = "https://chat.googleapis.com/v1/spaces/xxx/messages?key=abc-xyz&token=token-unique-key%3D"
 template_file = "message.tmpl"
 
 [app.http_client]
 max_idle_conns =  100
 request_timeout = 8000
+
+[app.chat.alertManagerTestRoom]
+notification_url = "https://chat.googleapis.com/v1/spaces/xxx/messages?key=abc-xyz&token=token-unique-key%3D"
+
+[app.chat.awesomeRoomTwo]
+notification_url = "https://chat.googleapis.com/v1/spaces/xxx/messages?key=abc-xyz&token=token-unique-key%3D"

examples/send_alert.sh

@@ -213,4 +213,4 @@ alerts1='{
    "groupKey":"{}:{alertname=\"Instance Down\"}"
 }'
 
-curl -XPOST -d"$alerts1" http://localhost:6000/create -i
+curl -XPOST -d"$alerts1" http://localhost:6000/create?room_name=alertManagerTestRoom -i

helper.go

@@ -10,7 +10,7 @@ import (
 	alerttemplate "github.com/prometheus/alertmanager/template"
 )
 
-func sendMessageToChat(alerts []alerttemplate.Alert, notif *Notifier) error {
+func sendMessageToChat(alerts []alerttemplate.Alert, notif *Notifier, webHookURL string) error {
 	var (
 		message = ChatNotification{}
 		str     strings.Builder
@@ -40,5 +40,5 @@ func sendMessageToChat(alerts []alerttemplate.Alert, notif *Notifier) error {
 	// prepare request payload for Google chat webhook endpoint
 	message.Text = str.String()
 
-	return notif.PushNotification(message)
+	return notif.PushNotification(message, webHookURL)
 }

main.go

@@ -95,7 +95,7 @@ func initPackage() {
 		}}
 
 	// Notifier for sending alerts.
-	notifier := NewNotifier(viper.GetString("app.notification_url"), *httpClient)
+	notifier := NewNotifier(*httpClient)
 
 	context := &App{notifier, sysLog}
 

notification.go

@@ -16,21 +16,20 @@ type Notifier struct {
 }
 
 // NewNotifier initialises a new instance of the Notifier.
-func NewNotifier(root string, h http.Client) Notifier {
+func NewNotifier(h http.Client) Notifier {
 	return Notifier{
-		root:       root,
 		httpClient: &h,
 	}
 }
 
 // PushNotification pushes out a notification to Google Chat Room.
-func (n *Notifier) PushNotification(notif ChatNotification) error {
+func (n *Notifier) PushNotification(notif ChatNotification, webHookURL string) error {
 	out, err := json.Marshal(notif)
 	if err != nil {
 		return err
 	}
 	// prepare POST request to webhook endpoint
-	req, err := http.NewRequest("POST", n.root, bytes.NewBuffer(out))
+	req, err := http.NewRequest("POST", webHookURL, bytes.NewBuffer(out))
 	if err != nil {
 		return err
 	}