more dynamic ip updating

[distro-setup] / switch-mail-host

diff --git a/switch-mail-host b/switch-mail-host
index 288211264ee5e377c2aed0b523d29f33fb52809a..5d7a6793388dd76b181b5b893eae590c4f1b1fdb 100755 (executable)
--- a/switch-mail-host
+++ b/switch-mail-host
@@ -65,8 +65,18 @@ if [[ ! $new_host || ! $old_host ]]; then
   exit 1
 fi
 
+# TODO: turn this home dns update into a separate script that also runs
+# as a cronjob for the MAIL_HOST, so it can update dns for a laptop that
+# moves to a different network.
+#
+# This exists because if mail_host is on the home network with a vpn
+# tunnel, and another host on the home network tries to connect to the
+# public tunnel ip, it won't work because from the public machine's
+# perspective, due to nat, both home network machines have the same
+# ip. We could solve this by using ipv6 addresses, but not all networks
+# i'm on with more than one machine are ipv6 enabled.
 at_home=false
-if [[ $HOSTNAME == tp ]] || [[ $HOSTNAME == frodo ]] || timeout -s 9 5 ssh wrt.b8.nz :; then
+if timeout -s 9 5 ssh-keyscan -p 2220 -t rsa 10.0.0.1 2>/dev/null | grep -qFx '[10.0.0.1]:2220 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCH+/h1dGEfKEusBblndU2e6QT4wLCm5+yqr/sqh/0X9YfjR7BfWWm8nNmuP55cYc+Wuf5ljB1H1acXEcsl1y8e0j3agHfF0V74FE1N1zz5nn2Ep8NHnmqgEhza38ZxMPh+4p3X7zklEKU7+3SzybKBi8sg0wLzlS2LM0JaUN80zR2sK11Kye3dURUXPk78u5wodOkgcEYRwSYaDMJlUzWP+poRXIDJwFaMQnwmxbl/c84yOyaU0x/d6hFwoRscWecihX+vvBNeSyxR4xr2HDOyUWwJkctyAgt2p7w3tfkXOKcCRzTAjGVIMQLTvo0sG/yJbcyHoEFdFybCsgDvfyYn'; then
   at_home=true
 fi
 echo "$0: at_home = $at_home"