Ensure prosody package key is world-readable (so apt user can read it)

Dockerfile

@@ -10,6 +10,7 @@ MAINTAINER Prosody Developers <developers@prosody.im>
 # Some dependencies in stretch are not suitable for Prosody 0.11.x, so add our repo
 RUN echo "deb http://packages.prosody.im/debian stretch main" > /etc/apt/sources.list.d/prosody.list
 ADD prosody_packages.gpg /etc/apt/trusted.gpg.d/prosody.gpg
+RUN chmod a+r /etc/apt/trusted.gpg.d/prosody.gpg
 
 # Install dependencies
 RUN apt-get update \
@@ -29,6 +30,7 @@ RUN apt-get update \
         lua-socket \
         lua-zlib \
         lua5.1 \
+        lua5.2 \
         openssl \
         ca-certificates \
         ssl-cert \
@@ -40,6 +42,8 @@ RUN dpkg -i /tmp/prosody.deb \
     && sed -i '1s/^/daemonize = false;\n/' /etc/prosody/prosody.cfg.lua \
     && perl -i -pe 'BEGIN{undef $/;} s/^log = {.*?^}$/log = {\n    {levels = {min = "info"}, to = "console"};\n}/smg' /etc/prosody/prosody.cfg.lua
 
+RUN mkdir -p /var/run/prosody && chown prosody:prosody /var/run/prosody
+
 COPY ./entrypoint.sh /entrypoint.sh
 RUN chmod 755 /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]