support dynamic max upload size on tus endpoint

docker/nginx/conf.d/client.conf

@@ -337,6 +337,23 @@ server {
 		# proxy /skynet/tus requests to siad endpoint with all arguments
 		proxy_pass http://siad;
 
+		# set max upload size dynamically based on account limits
+		rewrite_by_lua_block {
+			-- set default limit value to 1 GB
+			ngx.req.set_header("SkynetMaxUploadSize", 1073741824)
+
+			-- this block runs only when accounts are enabled
+			if os.getenv("ACCOUNTS_ENABLED", "0") == "0" then end
+
+			-- fetch account limits and set max upload size accordingly
+			local res = ngx.location.capture("/accounts/user/limits", { copy_all_vars = true })
+			if res.status == ngx.HTTP_OK then
+				local json = require('cjson')
+				local limits = json.decode(res.body)
+				ngx.req.set_header("SkynetMaxUploadSize", limits.maxUploadSize)
+			end
+		}
+
 		# extract skylink from base64 encoded upload metadata and assign to a proper header
 		header_filter_by_lua_block {
 			if ngx.header["Upload-Metadata"] then