CORS middleware

Signed-off-by: Peter Baker <peter.baker122@csiro.au>

Author: PeterBaker0

src/Middleware.jl

@@ -3,6 +3,26 @@ using HTTP
 using Dates
 using JSON
 
+const CORS_HEADERS = [
+    "Access-Control-Allow-Origin" => "*",
+    "Access-Control-Allow-Headers" => "*",
+    "Access-Control-Allow-Methods" => "POST, GET, OPTIONS"
+]
+
+# https://juliaweb.github.io/HTTP.jl/stable/examples/#Cors-Server
+function CorsMiddleware(handler)
+    return function(req::HTTP.Request)
+        @debug "CORS middleware"
+        # determine if this is a pre-flight request from the browser
+        if HTTP.method(req)=="OPTIONS"
+            return HTTP.Response(200, CORS_HEADERS)  
+        else 
+            return handler(req) # passes the request to the AuthMiddleware
+        end
+    end
+end
+
+
 function setup_jwt_middleware(config::Dict)
     if !get(config["jwt_auth"], "JWT_ENABLED", false)
         return identity  # Return a pass-through middleware if JWT is not enabled

src/ReefGuideAPI.jl

@@ -168,9 +168,9 @@ function start_server(config_path)
     println("Initialisation complete, starting server on port 8000.") 
     println("Starting with $(Threads.nthreads()) threads...") 
     if Threads.nthreads() > 1
-        serveparallel(host="0.0.0.0", port=8000)
+        serveparallel(middleware=[CorsMiddleware], host="0.0.0.0", port=8000)
     else
-        serve(host="0.0.0.0", port=8000)
+        serve(middleware=[CorsMiddleware], host="0.0.0.0", port=8000)
     end
 end