Add endpoint for QR Code generation

README.md

@@ -122,9 +122,19 @@ The group id can be obtained via the "List groups" REST call.
    
   ```curl -X POST -H "Content-Type: application/json" 'http://127.0.0.1:8080/v1/link/HomeAssistant'```
 
-  This provides a tsdevice link which have to be converted to a QR-Code, e.g. `qrencode -o linkqr.png tsdevice:...`
+  This provides a tsdevice link which have to be converted to a QR-Code. For this the endpoint /v1/qrcode/<tsdevice_link> ca be used.
 
 
+* Get QR Code
+
+  ```curl -X POST -H "Content-Type: application/json" 'http://127.0.0.1:8080/v1/qrcode/<tsdevice_link>'```
+
+  e.g:
+   
+  ```curl -X POST -H "Content-Type: application/json" 'http://127.0.0.1:8080/v1/qrcode/tsdevice:?uuid=ZiVIV..'```
+
+  This provides a QR-Code image. In case of an error a JSON object will be returned.
+
 
 The following REST API endpoints are **deprecated and no longer maintained!**
 

src/main.go

@@ -14,7 +14,9 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/h2non/filetype"
+	uuid "github.com/satori/go.uuid"
 	log "github.com/sirupsen/logrus"
+	qrcode "github.com/skip2/go-qrcode"
 )
 
 const groupPrefix = "group."
@@ -496,5 +498,23 @@ func main() {
 		}
 	})
 
+	router.GET("/v1/qrcode/:tsdevice_link", func(c *gin.Context) {
+		deviceLink := c.Param("tsdevice_link")
+
+		q, err := qrcode.New(deviceLink, qrcode.Medium)
+		if err != nil {
+			c.JSON(400, gin.H{"error": err.Error()})
+		}
+
+		q.DisableBorder = true
+		var png []byte
+		png, err = q.PNG(256)
+		if err != nil {
+			c.JSON(400, gin.H{"error": err.Error()})
+		}
+
+		c.Data(200, "image/png", png)
+	})
+
 	router.Run()
 }