fix: add valid origin check for cors (#83)

Resolves #72

server/middlewares/context.go

@@ -0,0 +1,23 @@
+package middlewares
+
+import (
+	"context"
+	"log"
+
+	"github.com/authorizerdev/authorizer/server/constants"
+	"github.com/gin-contrib/location"
+	"github.com/gin-gonic/gin"
+)
+
+func GinContextToContextMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if constants.AUTHORIZER_URL == "" {
+			url := location.Get(c)
+			constants.AUTHORIZER_URL = url.Scheme + "://" + c.Request.Host
+			log.Println("=> authorizer url:", constants.AUTHORIZER_URL)
+		}
+		ctx := context.WithValue(c.Request.Context(), "GinContextKey", c)
+		c.Request = c.Request.WithContext(ctx)
+		c.Next()
+	}
+}