Dockerfile

FROM            alpine as ngrok

RUN             apk add --no-cache --virtual .bootstrap-deps ca-certificates && \
                wget -O /tmp/ngrok.zip https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip && \
                unzip -o /tmp/ngrok.zip -d / && \
                apk del .bootstrap-deps && \
                rm -rf /tmp/* && \
                rm -rf /var/cache/apk/*

FROM            busybox:glibc

LABEL           maintainer="Dmitry Shkoliar @shkoliar"

COPY            --from=ngrok /ngrok /bin/ngrok
COPY            start.sh /
        
RUN             mkdir -p /home/ngrok /home/ngrok/.ngrok2 && \
                        printf 'web_addr: 0.0.0.0:4551' > /home/ngrok/.ngrok2/ngrok.yml && \
                        addgroup -g 4551 -S ngrok && \
                adduser -u 4551 -S ngrok -G ngrok -h /home/ngrok -s /bin/ash && \
                        chown -R ngrok:ngrok /home/ngrok && \
                chmod +x /start.sh

USER            ngrok:ngrok

EXPOSE          4551

ENTRYPOINT      ["/start.sh"]