add dockerfile

Dockerfile

+FROM zonemaster/engine:local as build
+
+RUN apk add --no-cache \
+    build-base \
+    make \
+    perl-dev \
+    perl-lwp-protocol-https \
+    #
+    perl-app-cpanminus \
+    perl-class-method-modifiers \
+    perl-config-inifiles \
+    perl-dbd-sqlite \
+    perl-dbi \
+    perl-file-sharedir \
+    perl-file-slurp \
+    perl-html-parser \
+    perl-mojolicious \
+    perl-io-stringy \
+    perl-libwww \
+    jq \
+    perl-log-any \
+    perl-log-dispatch \
+    perl-moose \
+    perl-parallel-forkmanager \
+    perl-plack \
+    perl-role-tiny \
+    perl-string-shellquote \
+    perl-try-tiny \
+    perl-net-server \
+    perl-role-tiny \
+    perl-test-nowarnings \
+    perl-test-nowarnings \
+    perl-test-simple \
+
+ && cpanm --no-wget --from=https://cpan.metacpan.org/ --notest \
+    Daemon::Control \
+    JSON::Validator \
+    JSON::PP \
+    Module::Find \
+    Plack::Middleware::ReverseProxy \
+    Starman \
+    Log::Any::Adapter::Dispatch \
+    Plack::Test \
+    String::ShellQuote \
+    JSON::RPC \
+    Router::Simple \
+    Net::Statsd
+
+ARG version
+
+COPY ./Zonemaster-Backend-${version}.tar.gz ./Zonemaster-Backend-${version}.tar.gz
+
+
+RUN cpanm --notest --no-wget \
+    ./Zonemaster-Backend-${version}.tar.gz
+
+FROM zonemaster/engine:local
+
+EXPOSE 5000
+VOLUME /etc/zonemaster
+
+RUN apk add --no-cache \
+    # All the locales we need and more
+    musl-locales \
+    jq \
+    # Run-time dependencies
+    perl-class-method-modifiers \
+    perl-config-inifiles \
+    perl-dbd-sqlite \
+    perl-dbd-pg \
+    perl-dbi \
+    perl-file-sharedir \
+    perl-file-slurp \
+    perl-html-parser \
+    perl-mojolicious \
+    perl-io-stringy \
+    perl-libwww \
+    perl-log-any \
+    perl-log-dispatch \
+    perl-moose \
+    perl-parallel-forkmanager \
+    perl-plack \
+    perl-role-tiny \
+    perl-string-shellquote \
+    perl-try-tiny \
+    perl-net-server \
+    perl-role-tiny
+
+COPY --from=build /usr/local/lib/perl5/site_perl /usr/local/lib/perl5/site_perl
+COPY --from=build /usr/local/share/perl5/site_perl /usr/local/share/perl5/site_perl
+COPY --from=build /usr/local/bin/zonemaster_backend_testagent /usr/local/bin/zonemaster_backend_testagent
+COPY --from=build /usr/local/bin/zonemaster_backend_rpcapi.psgi /usr/local/bin/zonemaster_backend_rpcapi.psgi