Schema validation: update HTTP sample 3

Author: andreyaksenov

doc/code_snippets/snippets/config/instances.enabled/application_role_http_api/http-api.lua

@@ -37,7 +37,10 @@ local function apply(cfg)
     if httpd then
         httpd:stop()
     end
-    httpd = require('http.server').new(cfg.host, cfg.port)
+    local cfg_with_defaults = listen_address_schema:apply_default(cfg)
+    local host = listen_address_schema:get(cfg_with_defaults, 'host')
+    local port = listen_address_schema:get(cfg_with_defaults, 'port')
+    httpd = require('http.server').new(host, port)
     local response_headers = { ['content-type'] = 'application/json' }
     httpd:route({ path = '/band/:id', method = 'GET' }, function(req)
         local id = req:stash('id')