Fixing snap package that was broken in the 1.2.0 update:

- Fix path to launch.sh - it's in the utils/ directory, not the top-level
- Version should be '1.2.0', previously it was some variable which looks like it comes from an external build program (this results in the snap being unable to build)
- Source of the novnc part has been fixed to reference the correct release file on github, not a 'build' directory on local machine (not present in the novnc sources)
- Websockify is now built direct from the 0.9.0 release on github. It appears that the version previously used (from the websockify package on Ubuntu) is too old to support 1.2.0 release of novnc (errors: "code 400, message Client must support 'binary' or 'base64' protocol")
- paths to launch.sh and svc_wrapper.sh have been corrected to where they actually are in the novnc sourc from github

snap/local/svc_wrapper.sh

@@ -24,6 +24,6 @@ snapctl get services | jq -c '.[]' | while read service; do # for each service t
         echo "novnc: not starting service ${service} with listen_port ${listen_port} and vnc_host_port ${vnc_host_port}"
     else
         # start (and fork with '&') the service using the specified listen port and VNC host:port
-        $SNAP/launch.sh --listen $listen_port --vnc $vnc_host_port &
+        $SNAP/utils/launch.sh --listen $listen_port --vnc $vnc_host_port &
     fi
 done

snap/snapcraft.yaml

@@ -1,6 +1,6 @@
 name: novnc
 base: core18 # the base snap is the execution environment for this snap
-version: '@VERSION@'
+version: 1.2.0
 summary: Open Source VNC client using HTML5 (WebSockets, Canvas)
 description: |
   Open Source VNC client using HTML5 (WebSockets, Canvas).
@@ -13,13 +13,17 @@ confinement: strict
 
 parts:
     novnc:
-        source: build/
+        source: https://github.com/novnc/noVNC/archive/v1.2.0.tar.gz
         plugin: dump
         stage-packages:
-            - websockify
             - bash
             - jq
-            - python-numpy
+            - python3-numpy
+            
+    websockify:
+        source: https://github.com/novnc/websockify/archive/v0.9.0.tar.gz
+        plugin: python
+        stage-packages:
             - python3-numpy
 
 hooks:
@@ -28,9 +32,9 @@ hooks:
 
 apps:
     novnc:
-        command: ./launch.sh
+        command: utils/launch.sh
         plugs: [network, network-bind]
     novncsvc:
-        command: ./svc_wrapper.sh
+        command: snap/local/svc_wrapper.sh
         daemon: forking
         plugs: [network, network-bind]