Refactor building and running of backend to functions

hack/tfw_magic_start.sh

@@ -32,15 +32,25 @@ build_baseimage()
     docker build -t "${BASEIMAGE_NAME}:${VERSION}-${DATE}" .
 }
 
-run_backend()
+build_backend()
 {
     cd $BACKEND_PATH
     docker build -t $IMAGE_NAME -f ${BUILD_CONTEXT}/Dockerfile --build-arg BUILD_CONTEXT=$BUILD_CONTEXT --build-arg NOFRONTEND=1 .
+}
+
+run_backend()
+{
     docker run --rm -p $BACKEND_PORT:$BACKEND_PORT -e AVATAO_SECRET=$AVATAO_SECRET $IMAGE_NAME
 }
 
+build_and_run_backend()
+{
+    build_backend
+    run_backend
+}
+
 trap 'exit' INT TERM
 trap 'kill 0' EXIT
 build_baseimage
-run_frontend & run_backend
+run_frontend & build_and_run_backend
 wait