rework cypress tests dockerfile:

- reduce to necessary dependencies
- control browser installation (chromium, firefox)
- use yarn for cypress installation

e2e-tests/cypress/Dockerfile

@@ -2,64 +2,31 @@
 # Dockerfile to create a ready-to-use Cypress Docker image for end-to-end
 # testing.
 #
-# This Dockerfile is based on the Dockerfile using Node.js 16.14.2 and
-# Cypress 10.3.0
-# (https://github.com/cypress-io/cypress-docker-images/blob/master/included/10.3.0/Dockerfile)
-# from Cypress.io Docker images.
+# Based on the images containing several browsers, provided by Cypress.io
+# (https://github.com/cypress-io/cypress-docker-images/tree/master/browsers)
+# this Dockerfile is based a slim Linux Dockerfile using Node.js 16.14.2.
+#
+# Here the latest stable versions of the browsers Chromium and Firefox are
+# installed before installing Cypress.
 ###############################################################################
-FROM cypress/browsers:node16.14.2-slim-chrome100-ff99-edge
+FROM cypress/base:16.14.2-slim
 
-# avoid too many progress messages
-# https://github.com/cypress-io/cypress/issues/1243
-ENV CI=1 \
-# disable shared memory X11 affecting Cypress v4 and Chrome
-# https://github.com/cypress-io/cypress-docker-images/issues/270
-  QT_X11_NO_MITSHM=1 \
-  _X11_NO_MITSHM=1 \
-  _MITSHM=0 \
-  # point Cypress at the /root/cache no matter what user account is used
-  # see https://on.cypress.io/caching
-  CYPRESS_CACHE_FOLDER=/root/.cache/Cypress \
-  # Allow projects to reference globally installed cypress
-  NODE_PATH=/usr/local/lib/node_modules
+# install dependencies
+RUN apt-get -qq update > /dev/null && \
+  apt-get -qq install -y bzip2 mplayer wget > /dev/null
 
-# should be root user
-RUN echo "whoami: $(whoami)" \
-  && npm config -g set user $(whoami) \
-  # command "id" should print:
-  # uid=0(root) gid=0(root) groups=0(root)
-  # which means the current user is root
-  && id \
-  && npm install -g "cypress@10.3.0" \
-  && cypress verify \
-  # Cypress cache and installed version
-  # should be in the root user's home folder
-  && cypress cache path \
-  && cypress cache list \
-  && cypress info \
-  && cypress version \
-  # give every user read access to the "/root" folder where the binary is cached
-  # we really only need to worry about the top folder, fortunately
-  && ls -la /root \
-  && chmod 755 /root \
-  # always grab the latest Yarn
-  # otherwise the base image might have old versions
-  # NPM does not need to be installed as it is already included with Node.
-  && npm i -g yarn@latest \
-  # Show where Node loads required modules from
-  && node -p 'module.paths' \
-  # should print Cypress version
-  # plus Electron and bundled Node versions
-  && cypress version \
-  && echo  " node version:    $(node -v) \n" \
-    "npm version:     $(npm -v) \n" \
-    "yarn version:    $(yarn -v) \n" \
-    "debian version:  $(cat /etc/debian_version) \n" \
-    "user:            $(whoami) \n" \
-    "chrome:          $(google-chrome --version || true) \n" \
-    "firefox:         $(firefox --version || true) \n"
+# install Chromium browser
+RUN apt-get -qq install -y chromium > /dev/null
+
+# install Firefox browser
+RUN wget --no-verbose -O /tmp/firefox.tar.bz2 "https://download.mozilla.org/?product=firefox-latest&os=linux64&lang=en-US" && \
+  tar -C /opt -xjf /tmp/firefox.tar.bz2 && \
+  rm /tmp/firefox.tar.bz2 && \
+  ln -fs /opt/firefox/firefox /usr/bin/firefox
+
+# clean up
+RUN rm -rf /var/lib/apt/lists/* && apt-get -qq clean > /dev/null
 
 WORKDIR /tests
 COPY tests/ /tests
-
-# ENTRYPOINT ["cypress", "run"]
+RUN yarn install