ioc: install user-specified runtime tarball packages.

This makes it possible to install software not packaged in the
distribution repositories, such as closed-source local packages.

`ldconfig` is executed at the end to refresh the dynamic linker library
resolution cache, which is required to identify new libraries installed
with lnls-get-n-unpack.

Dockerfile

@@ -7,17 +7,23 @@ FROM debian:${DEBIAN_VERSION}-slim AS base
 ARG RUNDIR
 ARG ENTRYPOINT=/bin/bash
 ARG RUNTIME_PACKAGES
+ARG RUNTIME_TAR_PACKAGES
 
 RUN apt update -y && \
     apt install -y --no-install-recommends \
         libreadline8 \
         busybox \
         netcat-openbsd \
         procserv \
+        wget \
         $RUNTIME_PACKAGES && \
     apt clean && \
     rm -rf /var/lib/apt/lists/*
 
+COPY --from=build-image /usr/local/bin/lnls-get-n-unpack /usr/local/bin/lnls-get-n-unpack
+RUN lnls-get-n-unpack -r $RUNTIME_TAR_PACKAGES && \
+    ldconfig
+
 WORKDIR ${RUNDIR}
 
 RUN ln -s ${ENTRYPOINT} ./entrypoint