feat(docker): add initial Dockerfile for c-lightning

docker/README.md

@@ -48,3 +48,25 @@ Replace `<version>` with the desired LND version (ex: `0.8.0-beta`)
 $ docker push polarlightning/lnd:<version>
 $ docker push polarlightning/lnd:latest
 ```
+
+## c-lightning
+
+### Tags
+
+- `0.7.3`, `latest` ([lnd/Dockerfile](https://github.com/jamaljsr/polar/blob/master/docker/clightning/Dockerfile))
+
+**Building the image**
+
+```sh
+$ cd clightning
+$ docker build --build-arg CLN_VERSION=<version> --build-arg BITCOIN_VERSION=0.18.1 -t polarlightning/clightning:latest -t polarlightning/clightning:<version> .
+```
+
+Replace `<version>` with the desired c-lightning version (ex: `0.7.3`). c-lightning requires `bitcoin-cli` >= v0.16.1 on the same machine, so the bitcoin version can be specified as a build arg as well.
+
+**Push to Docker Hub**
+
+```sh
+$ docker push polarlightning/clightning:<version>
+$ docker push polarlightning/clightning:latest
+```

docker/clightning/Dockerfile

@@ -0,0 +1,31 @@
+FROM ubuntu:18.04
+
+ARG CLN_VERSION
+# bitcoin-cli is required for c-lightning
+ARG BITCOIN_VERSION
+ENV PATH=/opt/bitcoin-${BITCOIN_VERSION}/bin:$PATH
+
+RUN apt-get update -y \
+  && apt-get install -y curl gosu wait-for-it xz-utils libsodium-dev \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+RUN curl -SLO https://bitcoin.org/bin/bitcoin-core-${BITCOIN_VERSION}/bitcoin-${BITCOIN_VERSION}-x86_64-linux-gnu.tar.gz \
+  && tar -xzf *.tar.gz -C /opt \
+  && rm *.tar.gz
+
+RUN curl -SLO https://github.com/ElementsProject/lightning/releases/download/v${CLN_VERSION}/clightning-v${CLN_VERSION}-Ubuntu-18.04.tar.xz  \
+  && tar -xf *.tar.xz -C / \
+  && rm *.tar.xz
+
+COPY docker-entrypoint.sh /entrypoint.sh
+
+RUN chmod a+x /entrypoint.sh
+
+VOLUME ["/home/clightning/.lightning"]
+
+EXPOSE 9735 8080 10000
+
+ENTRYPOINT ["/entrypoint.sh"]
+
+CMD ["lightningd"]

docker/clightning/docker-entrypoint.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+set -e
+
+# containers on linux share file permissions with hosts.
+# assigning the same uid/gid from the host user
+# ensures that the files can be read/write from both sides
+if ! id clightning > /dev/null 2>&1; then
+  USERID=${USERID:-1000}
+  GROUPID=${GROUPID:-1000}
+
+  echo "adding user clightning ($USERID:$GROUPID)"
+  groupadd -f -g $GROUPID clightning
+  useradd -r -u $USERID -g $GROUPID clightning
+  # create the .bitcoin dir for bitcoin-cli
+  mkdir -p /home/clightning/.bitcoin
+  chown clightning:clightning /home/clightning/.bitcoin
+fi
+
+if [ $(echo "$1" | cut -c1) = "-" ]; then
+  echo "$0: assuming arguments for lightningd"
+
+  set -- lightningd "$@"
+fi
+
+if [ "$1" = "lightningd" ] || [ "$1" = "lightning-cli" ]; then
+  echo "Running as clightning user: $@"
+  exec gosu clightning "$@"
+fi
+
+echo
+exec "$@"