1. #!/bin/bash
2.  
3. #Stop services for cleanup
4. sudo service rsyslog stop
5.  
6. #clear audit logs
7. if [ -f /var/log/wtmp ]; then
8.     truncate -s0 /var/log/wtmp
9. fi
10. if [ -f /var/log/lastlog ]; then
11.     truncate -s0 /var/log/lastlog
12. fi
13.  
14. #cleanup /tmp directories
15. rm -rf /tmp/*
16. rm -rf /var/tmp/*
17.  
18. #cleanup current ssh keys
19. rm -f /etc/ssh/ssh_host_*
20.  
21. #add check for ssh keys on reboot...regenerate if neccessary
22. cat << 'EOL' | sudo tee /etc/rc.local
23. #!/bin/sh -e
24. #
25. # rc.local
26. #
27. # This script is executed at the end of each multiuser runlevel.
28. # Make sure that the script will "" on success or any other
29. # value on error.
30. #
31. # In order to enable or disable this script just change the execution
32. # bits.
33. #
34. # By default this script does nothing.
35. # dynamically create hostname (optional)
36. #if hostname | grep localhost; then
37. #    hostnamectl set-hostname "$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 13 ; echo '')"
38. #fi
39. test -f /etc/ssh/ssh_host_dsa_key || dpkg-reconfigure openssh-server
40. exit 0
41. EOL
42.  
43. # make sure the script is executable
44. chmod +x /etc/rc.local
45.  
46. #reset hostname
47. # prevent cloudconfig from preserving the original hostname
48. sed -i 's/preserve_hostname: false/preserve_hostname: true/g' /etc/cloud/cloud.cfg
49. truncate -s0 /etc/hostname
50. hostnamectl set-hostname localhost
51.  
52. #cleanup apt
53. apt clean
54.  
55. # set dhcp to use mac - this is a little bit of a hack but I need this to be placed under the active nic settings
56. # also look in /etc/netplan for other config files
57. sed -i 's/optional: true/dhcp-identifier: mac/g' /etc/netplan/50-cloud-init.yaml
58.  
59. # cleans out all of the cloud-init cache / logs - this is mainly cleaning out networking info
60. sudo cloud-init clean --logs
61.  
62. #cleanup shell history
63. cat /dev/null > ~/.bash_history && history -c
64. history -w