From bf7cef54b1a82994929a20bfb849becf2b5d0961 Mon Sep 17 00:00:00 2001
From: Lennart Fleischmann <lennart.fleischmann@hanko.io>
Date: Fri, 12 Jul 2024 12:52:07 +0200
Subject: [PATCH] feat: add webhook env var decoder

---
 backend/config/webhook_config.go      | 21 +++++++++++++++++++++
 backend/config/webhook_config_test.go | 18 ++++++++++++++++++
 backend/docs/Config.md                |  4 ++++
 3 files changed, 43 insertions(+)
 create mode 100644 backend/config/webhook_config_test.go

diff --git a/backend/config/webhook_config.go b/backend/config/webhook_config.go
index fad155505..b2621c0a8 100644
--- a/backend/config/webhook_config.go
+++ b/backend/config/webhook_config.go
@@ -1,9 +1,11 @@
 package config
 
 import (
+	"encoding/json"
 	"fmt"
 	"github.com/teamhanko/hanko/backend/webhooks/events"
 	"net/url"
+	"strings"
 )
 
 type WebhookSettings struct {
@@ -27,6 +29,25 @@ func (ws *WebhookSettings) Validate() error {
 
 type Webhooks []Webhook
 
+// Decode is an implementation of the envconfig.Decoder interface.
+// Assumes that environment variables (for the WEBHOOKS_HOOKS key) have the following format:
+// {"callback":"http://app.com/usercb","events":["user"]};{"callback":"http://app.com/emailcb","events":["email.send"]}
+func (wd *Webhooks) Decode(value string) error {
+	webhooks := Webhooks{}
+	hooks := strings.Split(value, ";")
+	for _, hook := range hooks {
+		webhook := Webhook{}
+		err := json.Unmarshal([]byte(hook), &webhook)
+		if err != nil {
+			return fmt.Errorf("invalid map json: %w", err)
+		}
+		webhooks = append(webhooks, webhook)
+
+	}
+	*wd = webhooks
+	return nil
+}
+
 type Webhook struct {
 	Callback string        `yaml:"callback" json:"callback,omitempty" koanf:"callback"`
 	Events   events.Events `yaml:"events" json:"events,omitempty" koanf:"events"`
diff --git a/backend/config/webhook_config_test.go b/backend/config/webhook_config_test.go
new file mode 100644
index 000000000..606b93e2e
--- /dev/null
+++ b/backend/config/webhook_config_test.go
@@ -0,0 +1,18 @@
+package config
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestWebhooks_Decode(t *testing.T) {
+	webhooks := Webhooks{}
+	value := "{\"callback\":\"http://app.com/usercb\",\"events\":[\"user\"]};{\"callback\":\"http://app.com/callback\",\"events\":[\"email.send\"]}"
+	err := webhooks.Decode(value)
+
+	assert.NoError(t, err)
+	assert.Len(t, webhooks, 2, "has 2 elements")
+	for _, webhook := range webhooks {
+		assert.IsType(t, Webhook{}, webhook)
+	}
+}
diff --git a/backend/docs/Config.md b/backend/docs/Config.md
index d1ff17060..3b38fab85 100644
--- a/backend/docs/Config.md
+++ b/backend/docs/Config.md
@@ -1016,6 +1016,10 @@ webhooks:
     #
     # Callback - Endpoint URL to which the change data will be sent
     #
+    # NOTE: When using environment variables hooks must be defined as in the following example:
+    #
+    # WEBHOOKS_HOOKS={"callback":"http://app.com/usercb","events":["user"]};{"callback":"http://app.com/emailcb","events":["email.send"]}
+    #
     - callback: "<YOUR WEBHOOK ENDPOINT URL>"
       ##
       #