Getting latest GeckoDriver and Updating Firefox to 57.0.4 (#648)

* Using latest GeckoDriver version

* Upgrade Firefox patch to 57.0.4

Author: diemol

NodeFirefox/Dockerfile.txt

@@ -3,7 +3,7 @@ USER root
 #=========
 # Firefox
 #=========
-ARG FIREFOX_VERSION=57.0.2
+ARG FIREFOX_VERSION=57.0.4
 RUN apt-get update -qqy \
   && apt-get -qqy --no-install-recommends install firefox \
   && rm -rf /var/lib/apt/lists/* /var/cache/apt/* \
@@ -18,14 +18,16 @@ RUN apt-get update -qqy \
 #============
 # GeckoDriver
 #============
-ARG GECKODRIVER_VERSION=0.19.1
-RUN wget --no-verbose -O /tmp/geckodriver.tar.gz https://github.com/mozilla/geckodriver/releases/download/v$GECKODRIVER_VERSION/geckodriver-v$GECKODRIVER_VERSION-linux64.tar.gz \
+ARG GECKODRIVER_VERSION=latest
+RUN GK_VERSION=$(if [ ${GECKODRIVER_VERSION:-latest} = "latest" ]; then echo $(wget -qO- "https://api.github.com/repos/mozilla/geckodriver/releases/latest" | grep '"tag_name":' | sed -E 's/.*"v([0-9.]+)".*/\1/'); else echo $GECKODRIVER_VERSION; fi) \
+  && echo "Using GeckoDriver version: "$GK_VERSION \
+  && wget --no-verbose -O /tmp/geckodriver.tar.gz https://github.com/mozilla/geckodriver/releases/download/v$GK_VERSION/geckodriver-v$GK_VERSION-linux64.tar.gz \
   && rm -rf /opt/geckodriver \
   && tar -C /opt -zxf /tmp/geckodriver.tar.gz \
   && rm /tmp/geckodriver.tar.gz \
-  && mv /opt/geckodriver /opt/geckodriver-$GECKODRIVER_VERSION \
-  && chmod 755 /opt/geckodriver-$GECKODRIVER_VERSION \
-  && ln -fs /opt/geckodriver-$GECKODRIVER_VERSION /usr/bin/geckodriver
+  && mv /opt/geckodriver /opt/geckodriver-$GK_VERSION \
+  && chmod 755 /opt/geckodriver-$GK_VERSION \
+  && ln -fs /opt/geckodriver-$GK_VERSION /usr/bin/geckodriver
 
 # Install 'pulseaudio' package to support WebRTC audio streams
 RUN apt-get update && apt-get install -y pulseaudio