emscripten Dockerfile, slightly updated

Dockerfile

FROM buildpack-deps:bionic

RUN apt-get -y update && apt-get -y upgrade && apt-get -y install apt-utils

SHELL ["/bin/bash", "-c"]
ENV DEBIAN_FRONTEND=noninteractive LANG=C.UTF-8
RUN mkdir -p /root/emscripten/
COPY emscripten /root/emscripten/

RUN cd /root/ \
 && apt-get update \
 && apt-get install -y python cmake build-essential default-jre \
 && wget https://github.com/juj/emsdk/archive/master.tar.gz \
 && tar -xf master.tar.gz \
 && pushd emsdk-master \
 && ./emsdk update-tags \
 && ./emsdk install latest \
 && ./emsdk activate latest \
 && popd \
 && echo BINARYEN_ROOT="''" >> .emscripten \
 && echo 'export PATH=$PATH:/root/emscripten' >>/root/.bashrc