From c455a355ebf5d7e6030a43d20809d4f69ae96d6e Mon Sep 17 00:00:00 2001
From: Quentin Manfroi <quentin.manfroi@fr.clara.net>
Date: Mon, 19 Apr 2021 13:44:56 +0200
Subject: [PATCH] make install script reusable multiple times

---
 install.sh | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/install.sh b/install.sh
index 84cef78..f71bce6 100755
--- a/install.sh
+++ b/install.sh
@@ -1,10 +1,17 @@
 #!/bin/bash
+set -euo pipefail
 
-truncate -s0 /etc/motd           # empty native static motd
-mkdir -p /etc/update-motd.d/     # create dedicated directory following ubuntu
-cp motd /etc/update-motd.d/      # copy the static motd banner into it
-chmod -x /etc/update-motd.d/*    # disable any existing script
-cp scripts/* /etc/update-motd.d/ # enable claranet motd script
+# empty native static motd to prevent usage elsewhere (motd=/etc/motd from pam_motd.so or PrintMotd from sshd)
+truncate -s0 /etc/motd
+# create dedicated directory following ubuntu to contain required files
+mkdir -p /etc/update-motd.d/
+# copy the static motd banner into this directory in place of /etc/motd
+cp motd /etc/update-motd.d/
+# disable any existing script in this directory (e.g. for ubunutu)
+chmod -x /etc/update-motd.d/*
+# enable claranet motd script
+cp --preserve=mode scripts/* /etc/update-motd.d/
 
+echo "Claranet motd successfully installed!"
 echo "For distributions which does not use update-motd (e.g. ubuntu/debian), do not forget to add the following to /etc/pam.d/sshd:"
 echo "session    optional   pam_exec.so          stdout /etc/update-motd.d/00-basic"