fix: generalize the http status code returned to nginx when required

src/lua/api-gateway/validation/validator.lua

@@ -255,6 +255,25 @@ function BaseValidator:executeTtl(key)
     end
 end
 
+-- converts a response status to a valid HTTP status code
+function BaseValidator:convertToValidHttpStatusCode(response_status)
+    response_status = tonumber(response_status)
+    if response_status == nil then
+        return 500
+    end
+    if (response_status >= 100 and response_status <= 599) then
+        return response_status
+    end
+
+    local http_code_str = string.sub(tostring(response_status), 1, 3)
+    local http_code_number = tonumber(http_code_str)
+    if http_code_number ~= nil and http_code_number >= 100 and http_code_number <= 599 then
+        return http_code_number
+    end
+
+    ngx.log(ngx.DEBUG, "Status code: ", tostring(response_status), " is not in a valid HTTP Status Code format")
+    return 500
+end
 
 -- generic exit function for a validator --
 function BaseValidator:exitFn(status, resp_body)
@@ -269,9 +288,10 @@ function BaseValidator:exitFn(status, resp_body)
         end
     end
 
-    ngx.status = status
+    ngx.status = self:convertToValidHttpStatusCode(status)
 
     if (ngx.null ~= resp_body) then
+        ngx.header["Content-Type"] = "application/json"
         ngx.say(resp_body)
     end
 

src/lua/api-gateway/validation/validatorsHandlerErrorDecorator.lua

@@ -109,6 +109,15 @@ function ValidatorHandlerErrorDecorator:decorateResponse(response_status, respon
     response_status = tonumber(response_status)
 
     local o = getResponsesTemplate()[response_status]
+    -- If no match by status code (e.g. status was converted from an extended error_code like 401013 to 401),
+    -- try to extract the error_code from the response body and look up by that instead.
+    if (o == nil and response_body ~= nil and #response_body > 0 and response_body ~= "nil\n") then
+        local ok, json_body = pcall(cjson.decode, response_body)
+        if ok and json_body and json_body.error_code then
+            o = getResponsesTemplate()[tonumber(json_body.error_code)]
+        end
+    end
+
     if (o ~= nil) then
         ngx.status = self:convertToValidHttpStatusCode(o.http_status)
         -- NOTE: assumption: for the moment if it's custom, then it's application/json