Simplify Dockerfile

Change-Id: I302dc1bf83115007919c9745912812fac8ac6648
diff --git a/Dockerfile b/Dockerfile
index 304da77..a48f26c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,37 +1,34 @@
-# Setup container with Ubuntu 22.04 image
+# syntax=docker/dockerfile:1
+
 FROM ubuntu:22.04
 
-# Set the working directory to /
-WORKDIR /
-
-# expose ports for openvswitch-switch
-EXPOSE 6633 6653 6640
-
-# Update container image
-RUN apt-get update -y && \
+# Install dependencies
+RUN <<EOF
+    set -eux
+    apt-get update -y
     apt-get install --no-install-recommends -y \
         lsb-release sudo \
         zip unzip wget git ca-certificates \
         curl iproute2 iputils-ping net-tools \
-        python3 python3-pip \
-        tcpdump vim x11-xserver-utils xterm && \
-        update-ca-certificates && \
-    rm -rf /var/lib/apt/lists/* && \
-    alias python=python3
+        python3 python3-pip python-is-python3 \
+        tcpdump vim x11-xserver-utils xterm
+    rm -rf /var/lib/apt/lists/*
+    update-ca-certificates
+EOF
 
 COPY . /mini-ndn
-
-RUN cd mini-ndn && \
-    pip3 install -r requirements.txt && \
-    ./install.sh -y --source && \
-    cd dl/mininet && make install && cd ../.. && \
-    cd dl/mininet-wifi && make install && cd ../.. && \
-    rm -rf dl && rm -rf /var/lib/apt/lists/* && cd /
-
-COPY docker/ENTRYPOINT.sh /
-RUN chmod +x ENTRYPOINT.sh
-
-# Change the working directory to /mini-ndn
 WORKDIR /mini-ndn
 
-ENTRYPOINT ["/ENTRYPOINT.sh"]
+RUN <<EOF
+    set -eux
+    pip3 install -r requirements.txt
+    ./install.sh -y --source
+    make -C dl/mininet install
+    make -C dl/mininet-wifi install
+    rm -rf dl /var/lib/apt/lists/*
+EOF
+
+# Expose ports for openvswitch-switch
+EXPOSE 6633 6653 6640
+
+ENTRYPOINT ["docker/entrypoint.sh"]