Dockerfile

FROM alpine:latest
LABEL maintainer="James Z.M. Gao <gaozm55@gmail.com>"

ENV OC_VERSION=8.05

RUN set -ex \
# 1. install pptpclient
    && echo '@testing http://dl-cdn.alpinelinux.org/alpine/edge/testing' >> /etc/apk/repositories \
    && apk --update --no-progress upgrade \
    && apk add --no-progress ca-certificates pptpclient@testing \
# 2. build and install openconnect (ref: https://github.com/04n0/docker-openconnect-client)
## 2.1 install runtime and build dependencies
    && apk add --no-progress --virtual .openconnect-run-deps \
               gnutls gnutls-utils iptables libev libintl \
               libnl3 libseccomp linux-pam lz4-libs openssl \
               libxml2 nmap-ncat socat openssh-client \
    && apk add --no-progress --virtual .openconnect-build-deps \
               curl file g++ gnutls-dev gpgme gzip libev-dev \
               libnl3-dev libseccomp-dev libxml2-dev linux-headers \
               linux-pam-dev lz4-dev make readline-dev tar \
               sed readline procps \
## 2.2 download vpnc-script
    && mkdir -p /etc/vpnc \
    && curl https://gitlab.com/openconnect/vpnc-scripts/raw/master/vpnc-script -o /etc/vpnc/vpnc-script \
    && chmod 750 /etc/vpnc/vpnc-script \
## 2.3 create build dir, download, verify and decompress OC package to build dir
    && gpg --recv-key 0x63762cda67e2f359 \
    && mkdir -p /tmp/build/openconnect \
    && curl -SL "ftp://ftp.infradead.org/pub/openconnect/openconnect-$OC_VERSION.tar.gz" -o /tmp/openconnect.tar.gz \
    && curl -SL "ftp://ftp.infradead.org/pub/openconnect/openconnect-$OC_VERSION.tar.gz.asc" -o /tmp/openconnect.tar.gz.asc \
    && gpg --verify /tmp/openconnect.tar.gz.asc \
    && tar -xf /tmp/openconnect.tar.gz -C /tmp/build/openconnect --strip-components=1 \
## 2.4 build and install
    && cd /tmp/build/openconnect \
    && ./configure \
    && make \
    && make install \
    && cd / \
## 2.5 install dependency packages for openconnect csd wrapper
    && apk add --no-progress bash curl xmlstarlet \
# 3. fix ip command location for the pptp client
    && ln -s "$(which ip)" /usr/sbin/ip \
# 4. cleanup
    && apk del .openconnect-build-deps \
    && rm -rf /var/cache/apk/* /tmp/* ~/.gnupg

COPY content /

ENTRYPOINT ["/entrypoint.sh"]