nbde_client

Ansible role for configuring Network-Bound Disk Encryption clients (e.g. clevis).

This role currently supports clevis as a provider and it uses it for operations like encryption and decryption.

Supported Distributions

• RHEL-7+, CentOS-7+
• Fedora

Limitations

This role can currently create tang bindings. TPM2 is not supported as of now.

Role Variables

These are the variables that can be passed to the role:

Variable	Default/Choices	Description
nbde_client_provider	clevis	identifies the provider for the nbde_client role. We currently support clevis.
nbde_client_bindings		a list containing binding configurations, which include e.g. devices and slots.
nbde_client_early_boot	true	by default nbde_client will configure the initrd to unlock the volume. This may need to be disabled if the managed host is using static IP addressing, or if the volume should be unlocked by clevis-luks-askpass

nbde_client_bindings

nbde_client_bindings is a list of dictionaries that support the following keys:

Name	Default/Choices	Description
device		specifies the path of the backing device of an encrypted device on the managed host. This device must be already configured as a LUKS device before using the role (REQUIRED).
encryption_password		a valid password or passphrase for opening/unlocking the specified device. Recommend vault encrypting the value. See https://docs.ansible.com/ansible/latest/user_guide/vault.html
encryption_key_src		either the absolute or relative path, on the control node, of a file containing an encryption key valid for opening/unlocking the specified device. The role will copy this file to the managed node(s).
state	present / absent	specifies whether a binding with the configuration described should be added or removed. Setting state to present (the default) means a binding will be added; setting state to absent means a binding will be removed from the device/slot.
slot	1	specifies the slot to use for the binding.
servers		specifies a list of servers to bind to. To enable high availability, specify more than one server here.
threshold	1	specifies the threshold for the Shamir Secret Sharing (SSS) scheme that is put in place when using more than one server. When using multiple servers, threshold indicates how many of those servers should succeed, in terms of decryption, in order to complete the process of recovering the LUKS passphrase to open the device.
password_temporary	false	If true, the password or passphrase that was provided via the encryption_password or encryption_key arguments will be used to unlock the device and then it will be removed from the LUKS device after the binding operation completes, i.e. it will not be valid anymore. To be used if device has been previously created with a sample password or passphrase (for example by an automated install like kickstart that set up some sort of "default" password), which the role should replace by a stronger one.

Example:

nbde_client_bindings:
  - device: /dev/sda1
    encryption_key_src: /vault/keyfile
    state: present
    slot: 2
    threshold: 1
    password_temporary: false
    servers:
      - http://server1.example.com
      - http://server2.example.com

Example Playbooks

Example 1: high availability

---
- hosts: all
  vars:
    nbde_client_bindings:
      - device: /dev/sda1
        # recommend vault encrypting the encryption_password
        # see https://docs.ansible.com/ansible/latest/user_guide/vault.html
        encryption_password: password
        servers:
          - http://server1.example.com
          - http://server2.example.com
  roles:
    - linux-system-roles.nbde_client

Example 2: remove binding from slot 2 in /dev/sda1

---
- hosts: all
  vars:
    nbde_client_bindings:
      - device: /dev/sda1
        # recommend vault encrypting the encryption_password
        # see https://docs.ansible.com/ansible/latest/user_guide/vault.html
        encryption_password: password
        slot: 2
        state: absent
  roles:
    - linux-system-roles.nbde_client

License

MIT