build: Use heredoc for Dockerfile commands

Author: kroese

Dockerfile

@@ -9,12 +9,25 @@ ARG DEBCONF_NOWARNINGS="yes"
 ARG DEBIAN_FRONTEND="noninteractive"
 ARG DEBCONF_NONINTERACTIVE_SEEN="true"
 
-RUN groupadd --gid ${GID} bitcoin \
-  && useradd --create-home --no-log-init -u ${UID} -g ${GID} bitcoin \
-  && apt-get update -y \
-  && apt-get --no-install-recommends -y install jq curl gnupg gosu iputils-ping ca-certificates \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+RUN <<EOF
+  set -eu
+
+  # Create bitcoin user
+  groupadd --gid ${GID} bitcoin
+  useradd --create-home --no-log-init -u ${UID} -g ${GID} bitcoin
+
+  apt-get update -y
+  apt-get --no-install-recommends -y install \
+    jq \
+    curl \
+    gnupg \
+    gosu \
+    iputils-ping \
+    ca-certificates
+
+  apt-get clean
+  rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+EOF
 
 ARG TARGETPLATFORM
 
@@ -26,26 +39,57 @@ ENV BITCOIN_DATA=/home/bitcoin/.bitcoin
 ENV PATH=/opt/bitcoin-${BITCOIN_BASE}/bin:$PATH
 
 SHELL ["/bin/bash", "-c"]
-RUN set -eux \
-  && if [ -n "${BITCOIN_RC}" ]; then export SUBDIR=/test.; else export SUBDIR=; fi \
-  && export URL="https://bitcoincore.org/bin/bitcoin-core-${BITCOIN_VERSION}${SUBDIR}${BITCOIN_RC}" \
-  && if [ "${TARGETPLATFORM}" = "linux/amd64" ]; then export TARGETPLATFORM=x86_64-linux-gnu; fi \
-  && if [ "${TARGETPLATFORM}" = "linux/arm64" ]; then export TARGETPLATFORM=aarch64-linux-gnu; fi \
-  && if [ "${TARGETPLATFORM}" = "linux/arm/v7" ]; then export TARGETPLATFORM=arm-linux-gnueabihf; fi \
-  && SIGNERS=($(curl -sS "https://api.github.com/repos/bitcoin-core/guix.sigs/contents/${BITCOIN_BASE}" | jq -r '.[] | select(.type=="dir") | .name' | tr "\n" " ")) \
-  && for name in "${SIGNERS[@]}"; do \
-  curl -sSL "https://raw.githubusercontent.com/bitcoin-core/guix.sigs/main/builder-keys/${name}.gpg" | gpg --import - ; \
-  done \
-  && curl -SLO "${URL}/bitcoin-${BITCOIN_BASE}-${TARGETPLATFORM}.tar.gz" \
-  && curl -SLO "${URL}/SHA256SUMS" \
-  && curl -SLO "${URL}/SHA256SUMS.asc" \
-  && gpg --verify SHA256SUMS.asc SHA256SUMS \
-  && grep " bitcoin-${BITCOIN_BASE}-${TARGETPLATFORM}.tar.gz" SHA256SUMS | sha256sum -c - \
-  && tar -xzf ./*.tar.gz -C /opt \
-  && rm ./*.tar.gz ./*.asc \
-  && rm -rf "/opt/bitcoin-${BITCOIN_BASE}/bin/bitcoin-qt" \
-  && rm -rf "/opt/bitcoin-${BITCOIN_BASE}/bin/test_bitcoin"
-  
+
+RUN <<EOF
+  set -eux
+
+  # Determine Bitcoin Core release URL
+  if [ -n "${BITCOIN_RC}" ]; then
+    export SUBDIR=/test.
+  else
+    export SUBDIR=
+  fi
+
+  export URL="https://bitcoincore.org/bin/bitcoin-core-${BITCOIN_VERSION}${SUBDIR}${BITCOIN_RC}"
+
+  # Map Docker platform to Bitcoin Core archive platform
+  if [ "${TARGETPLATFORM}" = "linux/amd64" ]; then
+    export TARGETPLATFORM=x86_64-linux-gnu
+  fi
+
+  if [ "${TARGETPLATFORM}" = "linux/arm64" ]; then
+    export TARGETPLATFORM=aarch64-linux-gnu
+  fi
+
+  if [ "${TARGETPLATFORM}" = "linux/arm/v7" ]; then
+    export TARGETPLATFORM=arm-linux-gnueabihf
+  fi
+
+  # Import Bitcoin Core Guix signer keys
+  SIGNERS=($(curl -sS "https://api.github.com/repos/bitcoin-core/guix.sigs/contents/${BITCOIN_BASE}" | jq -r '.[] | select(.type=="dir") | .name' | tr "\n" " "))
+
+  for name in "${SIGNERS[@]}"; do
+    curl -sSL "https://raw.githubusercontent.com/bitcoin-core/guix.sigs/main/builder-keys/${name}.gpg" | gpg --import -
+  done
+
+  # Download Bitcoin Core release files
+  curl -SLO "${URL}/bitcoin-${BITCOIN_BASE}-${TARGETPLATFORM}.tar.gz"
+  curl -SLO "${URL}/SHA256SUMS"
+  curl -SLO "${URL}/SHA256SUMS.asc"
+
+  # Verify Bitcoin Core release
+  gpg --verify SHA256SUMS.asc SHA256SUMS
+  grep " bitcoin-${BITCOIN_BASE}-${TARGETPLATFORM}.tar.gz" SHA256SUMS | sha256sum -c -
+
+  # Install Bitcoin Core
+  tar -xzf ./*.tar.gz -C /opt
+
+  # Cleanup
+  rm ./*.tar.gz ./*.asc
+  rm -rf "/opt/bitcoin-${BITCOIN_BASE}/bin/bitcoin-qt"
+  rm -rf "/opt/bitcoin-${BITCOIN_BASE}/bin/test_bitcoin"
+EOF
+
 COPY --chmod=755 entrypoint.sh /entrypoint.sh
 
 VOLUME ["/home/bitcoin/.bitcoin"]