diff --git a/Dockerfile b/Dockerfile
index 0fdb2a7..1cce1e9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -47,9 +47,9 @@
     rm -rf /var/lib/apt/lists/*
 RUN pip install --upgrade pip setuptools 
 
-RUN packages='libsdl2-2.0 xserver-xorg libvulkan1' \
-	&& apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y $packages --no-install-recommends \
-    && VULKAN_API_VERSION=`dpkg -s libvulkan1 | grep -oP 'Version: [0-9|\.]+' | grep -oP '[0-9|\.]+'` && \
+RUN packages='libsdl2-2.0 xserver-xorg libvulkan1' && \
+	apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y $packages --no-install-recommends && \
+        VULKAN_API_VERSION=`dpkg -s libvulkan1 | grep -oP 'Version: [0-9|\.]+' | grep -oP '[0-9|\.]+'` && \
 	mkdir -p /etc/vulkan/icd.d/ && \
 	echo \
 	"{\
@@ -58,8 +58,8 @@
 			\"library_path\": \"libGLX_nvidia.so.0\",\
 			\"api_version\" : \"${VULKAN_API_VERSION}\"\
 		}\
-	}" > /etc/vulkan/icd.d/nvidia_icd.json \
-	&& rm -rf /var/lib/apt/lists/*
+	}" > /etc/vulkan/icd.d/nvidia_icd.json && \
+	rm -rf /var/lib/apt/lists/*
 
 # Error constructing proxy for org.gnome.Terminal:/org/gnome/Terminal/Factory0: Failed to execute child process dbus-launch (No such file or directory)
 # fix by setting LANG https://askubuntu.com/questions/608330/problem-with-gnome-terminal-on-gnome-3-12-2
@@ -94,7 +94,7 @@
         pkg-config \
         libelf-dev \
         gnupg patch xinit && \
-    rm -rf /var/lib/apt/lists/*
+     rm -rf /var/lib/apt/lists/*
 
 #        libc6:i386 \
 # (1-2) Install xorg server and xinit BEFORE INSTALLING NVIDIA DRIVER.
@@ -128,14 +128,14 @@
 #
 # Note: x11vnc in ubuntu18.04 is useless beacuse of stack smashing bug. See below to manual compilation.
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        mesa-utils lxterminal gnome-tweak-tool \
-        x11-apps && \
+    mesa-utils lxterminal gnome-tweak-tool \
+    x11-apps && \
     rm -rf /var/lib/apt/lists/*
 
 # solution for the `stack smashing detected` issue
 # https://github.com/LibVNC/x11vnc/issues/61
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        automake autoconf libssl-dev xorg-dev libvncserver-dev xdg-user-dirs xdg-utils && \
+    automake autoconf libssl-dev xorg-dev libvncserver-dev xdg-user-dirs xdg-utils && \
     rm -rf /var/lib/apt/lists/* && \
     git clone -b 0.9.16 https://github.com/LibVNC/x11vnc.git && \
     cd x11vnc && \
@@ -146,25 +146,22 @@
 # (2-2) Optional vulkan support
 # vulkan-utils includes vulkan-smoketest, benchmark software of vulkan API
 RUN apt-get update && apt-get install -y --no-install-recommends \
-      vulkan-utils \
-      firefox openbox menu \
-      alsa pulseaudio libgtk2.0-0 && \
+    vulkan-utils firefox openbox menu alsa pulseaudio libgtk2.0-0 && \
     rm -rf /var/lib/apt/lists/*
 
 # novnc
 # download websockify as well
 RUN wget https://github.com/novnc/noVNC/archive/v1.3.0.zip && \
-  unzip -q v1.3.0.zip && \
-  rm -rf v1.3.0.zip && \
-  git clone -b v0.10.0 https://github.com/novnc/websockify /noVNC-1.3.0/utils/websockify 
+    unzip -q v1.3.0.zip && \
+    rm -rf v1.3.0.zip && \
+    git clone -b v0.10.0 https://github.com/novnc/websockify /noVNC-1.3.0/utils/websockify 
 
 
 # Xorg segfault error
 # dbus-core: error connecting to system bus: org.freedesktop.DBus.Error.FileNotFound (Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory)
 # related? https://github.com/Microsoft/WSL/issues/2016
 RUN apt-get update && apt-get install -y --no-install-recommends \
-      dbus-x11 \
-      libdbus-c++-1-0v5 && \
+    dbus-x11 libdbus-c++-1-0v5 && \ 
     rm -rf /var/lib/apt/lists/*
 
 RUN echo "alias m='cd /home/$USERNAME ; su $USERNAME'" >> /home/$USERNAME/.bashrc 
@@ -173,23 +170,22 @@
 RUN sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
 RUN apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        ros-melodic-desktop-full \
-        python-rosdep \
-        python-rosinstall \
-        python-rosinstall-generator \
-        python-wstool \
-        && \
+    ros-melodic-desktop-full \
+    python-rosdep \
+    python-rosinstall \
+    python-rosinstall-generator \
+    python-wstool && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
 
 # addtional ROS package
 RUN apt-get update && apt-get install -y --no-install-recommends \
-        ros-melodic-derived-object-msgs \
-        ros-melodic-ackermann-msgs \
-        ros-melodic-ainstein-radar-msgs \
-        python3-numpy \
-        libomp-dev \
-        libomp5 && \
+    ros-melodic-derived-object-msgs \
+    ros-melodic-ackermann-msgs \
+    ros-melodic-ainstein-radar-msgs \
+    python3-numpy \
+    libomp-dev \
+    libomp5 && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*