Speedier Docker builds

Dockerfile

@@ -5,20 +5,19 @@ ENV LC_ALL C.UTF-8
 ENV DEBIAN_FRONTEND noninteractive
 
 # Make apt faster
-RUN echo force-unsafe-io > /etc/dpkg/dpkg.cfg.d/docker-apt-speedup
-RUN echo "Dpkg::Use-Pty=0;" > /etc/apt/apt.conf.d/99quieter
+RUN echo force-unsafe-io > /etc/dpkg/dpkg.cfg.d/docker-apt-speedup \
+ && echo "Dpkg::Use-Pty=0;" > /etc/apt/apt.conf.d/99quieter
 
-RUN apt-get update -qq
-RUN apt-get install -y -qq \
+RUN apt-get update -qq \
+ && apt-get install -y -qq \
   python3-pip \
   openvpn \
   strongswan
 
 # Dump on console what modules StrongSwan attempts to load
-RUN echo '#!/bin/bash' > /usr/sbin/modprobe
-RUN echo 'echo Attempting to load modules: $@' >> /usr/sbin/modprobe
-RUN cat /usr/sbin/modprobe
-RUN chmod +x /usr/sbin/modprobe
+RUN echo '#!/bin/bash' > /usr/sbin/modprobe \
+ && echo 'echo Attempting to load modules: $@' >> /usr/sbin/modprobe \
+ && chmod +x /usr/sbin/modprobe
 
 COPY entrypoint-openvpn.sh /entrypoint-openvpn.sh
 COPY entrypoint-strongswan.sh /entrypoint-strongswan.sh
@@ -27,6 +26,6 @@ COPY setup.py /src/
 COPY README.md /src/
 COPY misc/ /src/misc/
 WORKDIR /src
-RUN pip3 install .
-RUN echo "#!/bin/sh" > /usr/bin/chcon
-RUN chmod +x /usr/bin/chcon
+RUN pip3 install . \
+ && echo "#!/bin/sh" > /usr/bin/chcon \
+ && chmod +x /usr/bin/chcon