fix: support to mDNS/zeroconf in snap build, closes #58

snap/snapcraft.yaml

@@ -14,6 +14,9 @@ confinement: strict
 architectures:
   - build-on: amd64
 compression: lzo
+layout:
+  /etc/nsswitch.conf:
+    bind-file: $SNAP/etc/nsswitch.conf
 
 parts:
   antares:
@@ -71,11 +74,28 @@ parts:
   cleanup:
     after: [antares]
     plugin: nil
-    build-snaps: [ gnome-3-28-1804 ]
+    build-snaps: [gnome-3-28-1804]
     override-prime: |
-        set -eux
-        cd /snap/gnome-3-28-1804/current
-        find . -type f,l -exec rm -f $SNAPCRAFT_PRIME/{} \;
+      set -eux
+      cd /snap/gnome-3-28-1804/current
+      find . -type f,l -exec rm -f $SNAPCRAFT_PRIME/{} \;
+
+  mdns-lookup:
+    # Make resolution of ".local" host names (Zero-Conf/mDNS/DNS-SD)
+    # working: Take the original nsswitch.conf file from the base
+    # Snap and add "mdns4_minimal [NOTFOUND=return]" to its "hosts:" line
+    # Also install corresponding mdns4_minimal plug-in
+    # See: https://forum.snapcraft.io/t/no-mdns-support-in-snaps-should-core-have-a-modified-nsswitch-conf/
+    plugin: nil
+    stage-packages:
+      - libnss-mdns
+    override-prime: |
+      set -eux
+      sed -Ee 's/^\s*hosts:(\s+)files/hosts:\1files mdns4_minimal \[NOTFOUND=return\]/' /snap/core18/current/etc/nsswitch.conf > $SNAPCRAFT_STAGE/etc/nsswitch.conf
+      snapcraftctl prime
+    prime:
+      - lib/$SNAPCRAFT_ARCH_TRIPLET/libnss_mdns4_minimal*
+      - etc/nsswitch.conf
 
 apps:
   antares:
@@ -93,4 +113,4 @@ apps:
       - opengl
       - pulseaudio
       - removable-media
-      - unity7
+      - unity7