ci-base-image: entrypoint hackery to make sure PATH gets set

docker/Dockerfile

@@ -27,6 +27,12 @@ RUN apt-get clean
 
 RUN echo "runner ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/allow-runner-sudo
 RUN echo 'APT::Get::Assume-Yes "1";' > /etc/apt/apt.conf.d/75assume-yes
-RUN echo 'export PATH="$PATH:$HOME/.local/bin"' >> /home/runner/.bashrc
+
+# We get run with bash --login. That reads .bash_profile, but not .bashrc.
+RUN echo 'export PATH="$PATH:$HOME/.local/bin"' >> /home/runner/.bash_profile
 
 USER runner
+
+ADD entrypoint.sh /
+
+ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]

docker/entrypoint.sh

@@ -0,0 +1,15 @@
+# According to
+# https://docs.gitlab.com/runner/shells/#shell-profile-loading
+# Gitlab runner's docker executor does not load shell startup files,
+# because that's a great idea.
+cmd=()
+for i in "$@"; do
+  cmd+=("$(echo "$i"| sed "/exec/s/bash/bash --login/g")")
+done
+echo "Using rewritten shell invocation received from executor."
+echo "${cmd[@]}"
+"${cmd[@]}"
+retcode="$?"
+echo "return code from command: $retcode"
+exit "$retcode"
+