Back up Key Trustee Server using the ktbackup.sh script

Key Trustee Server releases 5.7 and higher include a script, ktbackup.sh, to simplify and automate backing up Key Trustee Server.

When run on a Key Trustee Server host, the script creates a tarball containing the Key Trustee Server private GPG keys and the PostgreSQL database.

To preserve the security of the backup, you must specify a GPG recipient. Because this recipient is the only entity that can decrypt the backup, the recipient must be someone authorized to access the Key Trustee Server database, such as a key administrator.

Creating and Importing a GPG Key for Encrypting and Decrypting Backups

If the key administrator responsible for backing up and restoring Key Trustee Server does not already have a GPG key pair, they can create one using the gpg --gen-key command. The following example demonstrates this procedure:

[john.doe@backup-host ~]$ gpg --gen-key
gpg (GnuPG) 2.0.14; Copyright (C) 2009 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
Your selection? 1
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048)
Requested keysize is 2048 bits
Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0)
Key does not expire at all
Is this correct? (y/N) y

GnuPG needs to construct a user ID to identify your key.

Real name: John Doe
Email address: john.doe@example.com
Comment: Key Trustee Backup
You selected this USER-ID:
    "John Doe (Key Trustee Backup) <john.doe@example.com>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
You need a Passphrase to protect your secret key.

can't connect to `/home/john.doe/.gnupg/S.gpg-agent': No such file or directory
gpg-agent[10638]: directory `/home/john.doe/.gnupg/private-keys-v1.d' created
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: /home/john.doe/.gnupg/trustdb.gpg: trustdb created
gpg: key 0936CB67 marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
pub   2048R/0936CB67 2016-02-10
      Key fingerprint = CE57 FDED 3AFE E67D 2041  9EBF E64B 7D00 0936 CB67
uid                  John Doe (Key Trustee Backup) <john.doe@example.com>
sub   2048R/52A6FC5C 2016-02-10

After the GPG key pair is generated, you can export the public key:

[john.doe@backup-host ~]$ gpg --armor --output /path/to/johndoe.pub --export 'John Doe'

Copy the public key (johndoe.pub in this example) to the Key Trustee Server host, and import it into the service account keyring (keytrustee for Key Trustee Server):

  • On the Key Trustee Server host:
    sudo -u keytrustee gpg --import /path/to/johndoe.pub

Running the ktbackup.sh Script

You must run ktbackup.sh as the service account. The location of the script depends on the service and installation method. See the following table for the script location and default service account for package- and parcel-based installations for Key Trustee Server.

Table 1. Backup Script Locations
Service Service Account Parcel-Based Installation Package-Based Installation
Key Trustee Server keytrustee /opt/cloudera/parcels/KEYTRUSTEE_SERVER/bin/ktbackup.sh /usr/bin/ktbackup.sh

The following table lists the command options for ktbackup.sh.

Table 2. Command Options for ktbackup.sh
Command Option Description
-c, --confdir=CONFDIR Specifies the Key Trustee configuration directory. Defaults to /var/lib/keytrustee/.keytrustee for parcel-based Key Trustee Server. For package-based Key Trustee Server, you must specify this option.
--database-port=PORT Specifies the Key Trustee Server database port. Defaults to 11381 for parcel-based installations. For package-based Key Trustee Server installations, you must specify this option.
--gpg-recipient=GPG_RECIPIENT Specifies the GPG recipient. The backup is encrypted with the public key of the specified recipient. The GPG recipient public key must be imported into the service account keyring before running the script.
--cleartext Outputs an unencrypted tarball. To preserve the security of the cryptographic keys, do not use this option in production environments.
--output=DIR Specifies the output directory for the tarball. Defaults to /var/lib/keytrustee for parcel-based Key Trustee Server. For package-based Key Trustee Server, you must specify this option.
--roll=n Deletes backups older than the last n backups from the directory specified by the --output parameter. For example, if you have 10 backups, specifying --roll=10 creates a new backup (11 backups total) and then delete the oldest backup. Specifying --roll=1 creates a new backup and then deletes all other backups.
-q, --quiet Suppresses console log messages and, if successful, returns only the backup tarball file path. This is useful for automating backups.
--verbose Outputs additional log messages to the console for debugging.

The following examples demonstrate the command usage for different scenarios:

  • To back up a parcel-based Key Trustee Server, specifying the GPG recipient by name:
    $ sudo -u keytrustee /opt/cloudera/parcels/KEYTRUSTEE_SERVER/bin/ktbackup.sh --gpg-recipient='John Doe'
  • To back up a package-based Key Trustee Server with the database running on a non-default port (12345 in this example):
    $ sudo -u keytrustee ktbackup.sh --database-port=12345 --gpg-recipient=john.doe@example.com

Automating Backups Using cron

You can schedule automatic backups of Key Trustee Server using the cron scheduling utility.

Create a crontab entry using the following commands:

  1. Edit the crontab by running the following command:
    sudo -u keytrustee crontab -e
  2. Add the following entry to run the backup script every 30 minutes. This example is for a parcel-based installation of Key Trustee Server. See the “Backup Script Locations” table for the package-based script location.
    */30 * * * * /opt/cloudera/parcels/KEYTRUSTEE_SERVER/bin/ktbackup.sh --gpg-recipient='John Doe' --quiet --output=/tmp/backups --roll=10

    Run man 5 crontab to see the crontab man page for details on using cron to schedule backups at different intervals.