Add Dockerfile.older.browser example on how to install older browsers

Author: elgalu

Dockerfile.older.browser

@@ -0,0 +1,30 @@
+# docker-selenium tags are pointer based, for instance:
+#   latest now points to 3 that points to 3.5 that points to 3.5.0 that points to 3.5.0-p1
+#   3.3 points to 3.3.1 that points to 3.3.1-p27
+#   and so on
+FROM elgalu/selenium:3.5
+
+USER root
+
+# In order to install an older chrome we need to:
+# 1. identify the git tag of the release that has that .deb version file
+#    e.g. 3.3.1-p22
+# 2. grab the .deb download url
+#    e.g. https://github.com/elgalu/....../google-chrome-stable_60.0.3112.101_amd64.deb
+RUN mkdir -p /home/seluser/chrome-deb \
+  && cd /home/seluser/chrome-deb \
+  && wget -O "older_chrome.deb" -nv \
+     "https://github.com/elgalu/docker-selenium/releases/download/3.3.1-p22/google-chrome-stable_60.0.3112.101_amd64.deb"
+
+# Installing the deb file will upgrade replace existing Chrome with the one we need
+RUN cd /home/seluser/chrome-deb \
+  && dpkg -i "older_chrome.deb" \
+  && rm "older_chrome.deb" \
+  && apt-get -qyy autoremove \
+  && rm -rf /var/lib/apt/lists/* \
+  && apt-get -qyy clean \
+  && export CH_STABLE_VER=$(/usr/bin/google-chrome-stable --version | grep -iEo "${GREP_ONLY_NUMS_VER}") \
+  && echo "${CH_STABLE_VER}"
+
+# Restore default user
+USER seluser