A script that creates a script that backs up the '/etc' folder. To use it, run `/etc/bak` after running the script below, as root.

bak.sh

#!/bin/sh

cat<<EOF>>/etc/bak.exclude
./etc/.pwd.lock
./etc/machine-id
./etc/mtab
./etc/multipath/bindings
./etc/openldap/schema
./etc/os-release
./etc/resolv.conf
./etc/ssh/ssh_host_*
EOF

cat<<EOF>>/etc/bak.include
./etc
./root/.ssh/authorized_keys
./var/lib/letsencrypt
EOF

cat<<EOF>>/etc/bak
#!/bin/sh
bak=/bak.\$(date -I).tar.gz
tar -C / -acpf \${1:-\${bak}} --exclude-from=/etc/bak.exclude --files-from=/etc/bak.include
EOF
chmod +x /etc/bak

I use this to save and clone my Clear Linux machines. The 'exclude' files are typical Clear Linux files that I want to drop.