raster rendering: return HTTP error if Vector Tile cannot be fetched

docker-entrypoint.sh

@@ -10,12 +10,24 @@ handle() {
 
 trap handle INT TERM
 
+refresh() {
+	SIGNAL=$(( $? - 128 ))
+	echo "Caught signal ${SIGNAL}, refreshing"
+	kill -s ${SIGNAL} $(pidof node) 2>/dev/null
+}
+
+trap refresh HUP
+
 if ! which -- "${1}"; then
   # first arg is not an executable
   xvfb-run -a --server-args="-screen 0 1024x768x24" -- node /app/ "$@" &
 	# Wait exits immediately on signals which have traps set. Store return value and wait
 	# again for all jobs to actually complete before continuing.
 	wait $! || RETVAL=$?
+	while [ ${RETVAL} = 129 ] ; do
+	  # Refressh signal HUP received. Continue waiting for signals.
+	  wait $! || RETVAL=$?
+	done
 	wait
 	exit ${RETVAL}
 fi

docs/usage.rst

@@ -29,8 +29,10 @@ Default preview style and configuration
 - If no configuration file is specified, a default preview style (compatible with openmaptiles) is used.
 - If no mbtiles file is specified (and is not found in the current working directory), a sample file is downloaded (showing the Zurich area)
 
-Reloading configuration
+Reloading the configuration
 ======
 
 It is possible to reload the configuration file without restarting the whole process by sending a SIGHUP signal to the node process.
-However, this does not currently work when running the tileserver-gl docker container (the signal is not passed to the subprocess, see https://github.com/maptiler/tileserver-gl/issues/420#issuecomment-597507663).
+
+- The `docker kill -s HUP tileserver-gl` command can be used when running the tileserver-gl docker container.
+- The `docker-compose kill -s HUP tileserver-gl-service-name` can be used when tileserver-gl is run as a docker-compose service.

src/serve_rendered.js

@@ -641,25 +641,30 @@ module.exports = {
                 const parts = url.parse(req.url);
                 const extension = path.extname(parts.pathname).toLowerCase();
                 const format = extensionToFormat[extension] || '';
-                if (err || res.statusCode < 200 || res.statusCode >= 300) {
+                // send empty response with status code 500 if vector tile server errors
+                if (res.statusCode >= 500) {
+                  console.log('HTTP error when fetching vector tile', err || res.statusCode);
+                  return false;
+                }
+                else if (err || res.statusCode < 200 || res.statusCode >= 300) {
                   // console.log('HTTP error', err || res.statusCode);
                   createEmptyResponse(format, '', callback);
                   return;
-                }
+                } else {
+                  const response = {};
+                  if (res.headers.modified) {
+                    response.modified = new Date(res.headers.modified);
+                  }
+                  if (res.headers.expires) {
+                    response.expires = new Date(res.headers.expires);
+                  }
+                  if (res.headers.etag) {
+                    response.etag = res.headers.etag;
+                  }
 
-                const response = {};
-                if (res.headers.modified) {
-                  response.modified = new Date(res.headers.modified);
-                }
-                if (res.headers.expires) {
-                  response.expires = new Date(res.headers.expires);
-                }
-                if (res.headers.etag) {
-                  response.etag = res.headers.etag;
+                  response.data = body;
+                  callback(null, response);
                 }
-
-                response.data = body;
-                callback(null, response);
               });
             }
           }