.github/Dockerfile with pkgx support

Author: gaggle

.dockerignore

@@ -0,0 +1,4 @@
+**
+!.pkgx.yaml
+!lib/**/*
+!mix.exs

.github/Dockerfile

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+FROM pkgxdev/pkgx as base
+# Set locale to utf8, without this Elixir warns:
+# > the VM is running with native name encoding of latin1 which may cause Elixir to malfunction as it expects utf8.
+# > Please ensure your locale is set to UTF-8 (which can be verified by running "locale" in your shell)
+# > or set the ELIXIR_ERL_OPTIONS="+fnu" environment variable
+RUN apt-get -y install locales
+RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && locale-gen
+ENV LANG en_US.UTF-8
+ENV LANGUAGE en_US:en
+ENV LC_ALL en_US.UTF-8
+
+FROM base as build
+WORKDIR /action/workspace
+
+# System dependencies
+COPY ../.pkgx.yaml .
+RUN eval "$(pkgx --internal.activate $PWD)"
+
+# Mix dependencies
+COPY ../mix.exs .
+RUN eval "$(pkgx --internal.activate $PWD)" && mix deps.get
+
+# Compile
+COPY ../lib lib
+RUN eval "$(pkgx --internal.activate $PWD)" && mix deps.compile
+RUN eval "$(pkgx --internal.activate $PWD)" && mix escript.build
+
+FROM base as release
+COPY --from=build /root/.pkgx /root/.pkgx
+COPY --from=build /action/workspace/.pkgx.yaml /usr/local/bin
+COPY --from=build /action/workspace/elixir_script /usr/local/bin
+RUN echo '#!/bin/sh\n\
+eval "$(pkgx --internal.activate /usr/local/bin)"\n\
+exec /usr/local/bin/elixir_script "$@"' > /usr/local/bin/elixir_script_wrapper && \
+chmod +x /usr/local/bin/elixir_script_wrapper
+
+ENTRYPOINT ["elixir_script_wrapper"]