network: Add MDNS support for .local domains

This requires the initialisation of both DBus and
Avahi in the `entry.sh` script to allow resolution
via libc.

Due to issues with Avahi's `init.d` script, the previous
PIDfile is explicitly removed.

Connects-to: #712
Change-type: minor
Signed-off-by: Heds Simons <heds@resin.io>

Dockerfile

@@ -98,7 +98,7 @@ RUN [ "cross-build-end" ]
 ##############################################################################
 
 # Minimal runtime image
-FROM resin/$ARCH-supervisor-base:v1.2.0
+FROM resin/$ARCH-supervisor-base:v1.3.0
 ARG ARCH
 ARG VERSION=master
 ARG DEFAULT_MIXPANEL_TOKEN=bananasbananas
@@ -109,6 +109,9 @@ COPY --from=node-build /usr/src/app/dist ./dist
 COPY --from=node-deps /build/node_modules ./node_modules
 COPY --from=node-deps /build/rootfs-overlay/ /
 
+# Remove default nproc limit for Avahi for it to work in-container
+COPY avahi-daemon.conf /etc/avahi/avahi-daemon.conf
+
 VOLUME /data
 
 ENV CONFIG_MOUNT_POINT=/boot/config.json \

avahi-daemon.conf

@@ -0,0 +1,67 @@
+# This file is part of avahi.
+#
+# avahi is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 2 of the
+# License, or (at your option) any later version.
+#
+# avahi is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with avahi; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+# USA.
+
+# See avahi-daemon.conf(5) for more information on this configuration
+# file!
+
+[server]
+#host-name=foo
+#domain-name=local
+#browse-domains=0pointer.de, zeroconf.org
+use-ipv4=yes
+use-ipv6=yes
+#allow-interfaces=eth0
+#deny-interfaces=eth1
+#check-response-ttl=no
+#use-iff-running=no
+#enable-dbus=yes
+#disallow-other-stacks=no
+#allow-point-to-point=no
+#cache-entries-max=4096
+#clients-max=4096
+#objects-per-client-max=1024
+#entries-per-entry-group-max=32
+ratelimit-interval-usec=1000000
+ratelimit-burst=1000
+
+[wide-area]
+enable-wide-area=yes
+
+[publish]
+#disable-publishing=no
+#disable-user-service-publishing=no
+#add-service-cookie=no
+#publish-addresses=yes
+publish-hinfo=no
+publish-workstation=no
+#publish-domain=yes
+#publish-dns-servers=192.168.50.1, 192.168.50.2
+#publish-resolv-conf-dns-servers=yes
+#publish-aaaa-on-ipv4=yes
+#publish-a-on-ipv6=no
+
+[reflector]
+#enable-reflector=no
+#reflect-ipv=no
+
+[rlimits]
+#rlimit-as=
+rlimit-core=0
+rlimit-data=4194304
+rlimit-fsize=0
+rlimit-nofile=768
+rlimit-stack=4194304

entry.sh

@@ -2,6 +2,12 @@
 
 set -o errexit
 
+# Start Avahi to allow MDNS lookups
+mkdir -p /var/run/dbus
+rm -f /var/run/avahi-daemon/pid
+/etc/init.d/dbus-1 start
+/etc/init.d/avahi-daemon start
+
 [ -d /mnt/root/tmp/resin-supervisor ] ||
     mkdir -p /mnt/root/tmp/resin-supervisor