content: FROM docker.io/library/ubuntu:20.04
  
  # metadata
  ARG VCS_REF
  ARG BUILD_DATE
  ARG POLKADOT_VERSION
  ARG POLKADOT_GPGKEY=9D4B2B6EB8F97156D19669A9FF0812D491B96798
  ARG GPG_KEYSERVER="keyserver.ubuntu.com"
  
  LABEL io.parity.image.authors="devops-team@parity.io" \
  	io.parity.image.vendor="Parity Technologies" \
  	io.parity.image.title="parity/polkadot" \
  	io.parity.image.description="Polkadot: a platform for web3. This is the official Parity image with an injected binary." \
  	io.parity.image.source="https://github.com/paritytech/polkadot/blob/${VCS_REF}/scripts/ci/dockerfiles/polkadot_injected_release.Dockerfile" \
  	io.parity.image.revision="${VCS_REF}" \
  	io.parity.image.created="${BUILD_DATE}" \
  	io.parity.image.documentation="https://github.com/paritytech/polkadot/"
  
  # show backtraces
  ENV RUST_BACKTRACE 1
  
  # install tools and dependencies
  RUN apt-get update && \
  	DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
  		libssl1.1 \
  		ca-certificates \
  		gnupg && \
  	useradd -m -u 1000 -U -s /bin/sh -d /polkadot polkadot && \
  # add repo's gpg keys and install the published polkadot binary
  	gpg --keyserver ${GPG_KEYSERVER} --recv-keys ${POLKADOT_GPGKEY} && \
  	gpg --export ${POLKADOT_GPGKEY} > /usr/share/keyrings/parity.gpg && \
  	echo 'deb [signed-by=/usr/share/keyrings/parity.gpg] https://releases.parity.io/deb release main' > /etc/apt/sources.list.d/parity.list && \
  	apt-get update && \
  	apt-get install -y --no-install-recommends polkadot=${POLKADOT_VERSION#?} && \
  # apt cleanup
  	apt-get autoremove -y && \
  	apt-get clean && \
  	rm -rf /var/lib/apt/lists/* ; \
  	mkdir -p /data /polkadot/.local/share && \
  	chown -R polkadot:polkadot /data && \
  	ln -s /data /polkadot/.local/share/polkadot
  
  USER polkadot
  
  # check if executable works in this container
  RUN /usr/bin/polkadot --version
  RUN /usr/local/bin/polkadot-execute-worker --version
  RUN /usr/local/bin/polkadot-prepare-worker --version
  
  EXPOSE 30333 9933 9944
  VOLUME ["/polkadot"]
  
  ENTRYPOINT ["/usr/bin/polkadot"]
  