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Securing services with SSL certificates

The OpenStack Security Guide recommends providing secure communication between various services in an OpenStack deployment.

The OpenStack-Ansible project currently offers the ability to configure SSL certificates for secure communication with the following services:

  • HAProxy
  • Horizon
  • Keystone
  • RabbitMQ

For each service, you have the option to use self-signed certificates generated during the deployment process or provide SSL certificates, keys, and CA certificates from your own trusted certificate authority. Highly secured environments use trusted, user-provided, certificates for as many services as possible.

Note

Conduct all SSL certificate configuration in /etc/openstack_deploy/user_variables.yml and not in the playbook roles themselves.

Self-signed certificates

Self-signed certificates ensure you are able to start quickly and you are able to encrypt data in transit. However, they do not provide a high level of trust for highly secure environments. The use of self-signed certificates is currently the default in OpenStack-Ansible. When self-signed certificates are being used, certificate verification must be disabled using the following user variables depending on your configuration. Add these variables in /etc/openstack_deploy/user_variables.yml.

keystone_service_adminuri_insecure: true
keystone_service_internaluri_insecure: true

Setting self-signed certificate subject data

Change the subject data of any self-signed certificate using configuration variables. The configuration variable for each service is <servicename>_ssl_self_signed_subject. To change the SSL certificate subject data for HAProxy, adjust /etc/openstack_deploy/user_variables.yml:

haproxy_ssl_self_signed_subject: "/C=US/ST=Texas/L=San Antonio/O=IT/CN=haproxy.example.com"

For more information about the available fields in the certificate subject, refer to OpenSSL’s documentation on the req subcommand.

Generating and regenerating self-signed certificates

Generate self-signed certificates for each service during the first run of the playbook.

Note

Subsequent runs of the playbook do not generate new SSL certificates unless you set <servicename>_ssl_self_signed_regen to true.

To force a self-signed certificate to regenerate, you can pass the variable to openstack-ansible on the command line:

# openstack-ansible -e "horizon_ssl_self_signed_regen=true" os-horizon-install.yml

To force a self-signed certificate to regenerate with every playbook run, set the appropriate regeneration option to true. For example, if you have already run the os-horizon playbook, but you want to regenerate the self-signed certificate, set the horizon_ssl_self_signed_regen variable to true in /etc/openstack_deploy/user_variables.yml:

horizon_ssl_self_signed_regen: true

Note

Regenerating self-signed certificates replaces the existing certificates whether they are self-signed or user-provided.

User-provided certificates

You can provide your own SSL certificates, keys, and CA certificates for added trust in highly secure environments. Acquiring certificates from a trusted certificate authority is outside the scope of this document, but the

Certificate Management section of the Linux Documentation Project explains

how to create your own certificate authority and sign certificates.

Deploying user-provided SSL certificates is a three step process:

  1. Copy your SSL certificate, key, and CA certificate to the deployment host.
  2. Specify the path to your SSL certificate, key, and CA certificate in /etc/openstack_deploy/user_variables.yml.
  3. Run the playbook for that service.

For example, to deploy user-provided certificates for RabbitMQ, copy the certificates to the deployment host, edit /etc/openstack_deploy/user_variables.yml and set the following three variables:

rabbitmq_user_ssl_cert:    /tmp/example.com.crt
rabbitmq_user_ssl_key:     /tmp/example.com.key
rabbitmq_user_ssl_ca_cert: /tmp/ExampleCA.crt

Run the playbook to apply the certificates:

# openstack-ansible rabbitmq-install.yml

The playbook deploys your user-provided SSL certificate, key, and CA certificate to each RabbitMQ container.

The process is identical to the other services. Replace rabbitmq in the configuration variables shown above with horizon, haproxy, or keystone to deploy user-provided certificates to those services.