Convert to Alpine

Brings image size from ~270MB to ~200MB

Dockerfile

@@ -2,7 +2,7 @@ ARG ARCH=amd64
 ARG ELECTRUM_VERSION=3.3.8
 ARG ELECTRUM_INSTALL_DIR=/opt/electrum
 
-FROM $ARCH/python:3.7-slim-buster as builder
+FROM $ARCH/python:3.7-alpine as builder
 
 ARG ELECTRUM_VERSION
 ARG ELECTRUM_INSTALL_DIR
@@ -10,15 +10,15 @@ ARG ELECTRUM_INSTALL_DIR
 RUN mkdir $ELECTRUM_INSTALL_DIR
 WORKDIR $ELECTRUM_INSTALL_DIR
 
-RUN apt-get update
-RUN apt-get install -y git
+RUN apk update
+RUN apk add --no-cache git
 RUN git clone git://github.com/spesmilo/electrum.git $ELECTRUM_INSTALL_DIR
 RUN git checkout $ELECTRUM_VERSION
 RUN git submodule update --init
-RUN apt-get install -y build-essential libssl-dev libffi-dev python3-dev
+RUN apk add --no-cache gcc musl-dev python3-dev libffi-dev openssl-dev
 RUN python3 -m pip install --user . cryptography
 
-FROM $ARCH/python:3.7-slim-buster as ephemeral-electrum
+FROM $ARCH/python:3.7-alpine as ephemeral-electrum
 LABEL maintainer="Luke Childs <lukechilds123@gmail.com>"
 
 ARG ELECTRUM_INSTALL_DIR
@@ -27,9 +27,8 @@ COPY --from=builder $ELECTRUM_INSTALL_DIR $ELECTRUM_INSTALL_DIR
 COPY --from=builder /root/.local /root/.local
 
 RUN ln -s $ELECTRUM_INSTALL_DIR/run_electrum /usr/local/bin/electrum && \
-  apt-get update && \
-  apt-get install -y libsecp256k1-0 && \
-  rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+  apk update && \
+  apk add --no-cache git
 
 WORKDIR /root
 

entrypoint

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 seed=$1
 server=$2