Wait for internet connection before starting the setup

scripts/Common/Scripts/wait-network.fish

@@ -0,0 +1,50 @@
+#!/bin/env fish
+function waitNetwork -a witness
+    set -l timeout (math 10 \* 60)
+    set -l codeFile (mktemp)
+
+    if [ -z "$witness" ]
+        tmux new-session -d 'cat /etc/motd; echo "$(tput bold)Please establish an internet connection…$(tput sgr0)"; $SHELL'
+
+        if not systemctl --quiet is-active network-online.target
+            fish (status filename) true &
+            set -l pid "$last_pid"
+
+            function witnessHandler -V codeFile --on-process-exit "$pid" -a event pid code
+                echo "$code" > "$codeFile"
+
+                if [ "$code" -gt 0 ]
+                    echo "Unable to connect to the internet!"
+                end
+            end
+
+            tmux attach
+            wait "$pid"
+            return "$(cat "$codeFile")"
+        end
+    else
+        set -l x 0
+
+        while true
+            set x (math $x + 1)
+
+            if systemctl --quiet is-active network-online.target
+                tmux kill-session &> /dev/null
+                break
+            else
+                not tmux list-sessions &> /dev/null
+                or test "$x" -gt 10
+                and begin
+                    tmux kill-session &> /dev/null
+                    exit 1
+                end
+            end
+
+            sleep 1
+        end
+    end
+end
+
+if [ -n "$argv" ]
+    waitNetwork $argv
+end