Merge pull request #5916 from ryanlovett/datahub-man

Enable man.

deployments/datahub/images/default/Dockerfile

@@ -21,6 +21,9 @@ RUN apt-get -qq update --yes && \
 
 RUN adduser --disabled-password --gecos "Default Jupyter user" ${NB_USER}
 
+# Do not exclude manpages from being installed.
+RUN sed -i -e '/usr.share.man/s/^/#/' /etc/dpkg/dpkg.cfg.d/excludes
+
 # Install all apt packages
 COPY apt.txt /tmp/apt.txt
 RUN apt-get -qq update --yes && \
@@ -30,6 +33,15 @@ RUN apt-get -qq update --yes && \
     apt-get -qq clean && \
     rm -rf /var/lib/apt/lists/*
 
+# From docker-ce-packaging
+# Remove diverted man binary to prevent man-pages being replaced with "minimized" message. See docker/for-linux#639
+RUN if  [ "$(dpkg-divert --truename /usr/bin/man)" = "/usr/bin/man.REAL" ]; then \
+        rm -f /usr/bin/man; \
+        dpkg-divert --quiet --remove --rename /usr/bin/man; \
+    fi
+
+RUN mandb -c
+
 # Create user owned R libs dir
 # This lets users temporarily install packages
 RUN install -d -o ${NB_USER} -g ${NB_USER} ${R_LIBS_USER}