Fix clustering on fly with versioned Docker image

Author: jonatanklosko

rel/server/env.sh.eex

@@ -9,7 +9,8 @@ if [ "$LIVEBOOK_CLUSTER" = "auto" ] && [ ! -z "$FLY_APP_NAME" ]; then
   esac
 
   if [ -z "${LIVEBOOK_NODE}" ]; then
-    export LIVEBOOK_NODE="${FLY_APP_NAME}-${FLY_IMAGE_REF##*:}@${FLY_PRIVATE_IP}"
+    deployment="$(echo "$FLY_IMAGE_REF" | shasum | cut -c 1-10)"
+    export LIVEBOOK_NODE="${FLY_APP_NAME}-${deployment}@${FLY_PRIVATE_IP}"
   fi
 fi