Doppelganger

Doppelganger is configured as Herald with the following exceptions:

  1. Change the hostname in /etc/config/system.
  2. Change /etc/config/fstab to match the attached disk.
  3. Edit the files in /etc that refer to the attached disk’s mount point.
  4. Configure logging in a way appropriate for the host network. This might involve removing syslog-ng and reverting to use logd.
  5. Adjust mynetworks in Postfix’s /etc/postfix/main.cf, because Doppelganger might exist on a different network than Herald.
  6. Adjust /etc/postfix/saslpasswd and relayhost in Postfix’s /etc/postfix/main.cf to use a relay appropriate for Doppelganger’s network. Compile with postmap.
  7. Set listen = 127.0.0.1 in Dovecot’s /etc/dovecot/dovecot.conf, as mail on Doppelganger must be checked using webmail.
  8. add accounts for mail users to /etc/passwd and /etc/shadow if LDAP is unavailable. Add mydestination = EXAMPLE.COM to /etc/postfix/main.cf. Also, avoid the use of virtual_mailbox_domains, virtual_mailbox_maps, virtual_mailbox_lock, virtual_uid_maps and virtual_gid_maps in /etc/postfix/main.cf.

Once Doppelganger is running, you might want to synchronize it with Herald:

  1. On Herald, generate an SSH key pair: dropbearkey -t rsa -f ~/.ssh/id_dropbear -s 4096.
  2. Install the public key on Doppelganger at /etc/dropbear/authorized_keys.
  3. On Herald, run rsync --progress --delete -aHe ssh /mnt/sda1/* root@doppelganger.EXAMPLE.COM:/mnt/sda1/.

My research interests include free and open source software, system security, and network security.