14. Security Best Practices¶

14.3.1. Minimize administrative accounts¶

Minimizing the access to system administrative accounts is crucial for maintaining a secure system. A system administrator/root user can access, edit, and disrupt any system application. Keep the number of people/accounts with root access to as small of a group as possible. Do not give out sudo to root or awx (the Tower user) to untrusted users. Know that when restricting administrative access via mechanisms like sudo, that restricting to a certain set of commands may still give a wide range of access. Any command that allows for execution of a shell or arbitrary shell commands, or any command that can change files on the system, is fundamentally equivalent to full root access.

In a Tower context, any Tower ‘system administrator’ or ‘superuser’ account can edit, change, and update any inventory or automation definition in Tower. Restrict this to the minimum set of users possible for low-level Tower configuration and disaster recovery only.

14.3.2. Minimize local system access¶

Ansible Tower, when used with best practices, should not require local user access except for administrative purposes. Non-administrator users should not have access to the Tower system.

14.3.3. Remove access to credentials from users¶

If an automation credential is only stored in Tower, it can be further secured. Services such as OpenSSH can be configured to only allow credentials on connections from specific addresses. Credentials used by automation can be different than credentials used by system administrators for disaster-recovery or other ad-hoc management, allowing for easier auditing.

14.3.4. Enforce separation of duties¶

Different pieces of automation may need to access a system at different levels. For example, you may have low-level system automation that applies patches and performs security baseline checking, while a higher-level piece of automation deploys applications. By using different keys or credentials for each piece of automation, the effect of any one key vulnerability is minimized, while also allowing for easy baseline auditing.

14.4.1. Audit and logging functionality¶

For any administrative access, it is key to audit and watch for actions. For the system overall, this can be done via the built in audit support (https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Security_Guide/chap-system_auditing.html) and via the built-in logging support.

For Ansible Tower, this is done via the built-in Activity Stream support that logs all changes within Tower, as well as via the automation logs.

Best practices dictate collecting logging and auditing centrally, rather than reviewing it on the local system. It is recommended that Ansible Tower be configured to use whatever IDS and/or logging/auditing (Splunk) is standard in your environment. Ansible Tower includes built-in logging integrations for Elastic Stack, Splunk, Sumologic, Loggly, and more. See Tower Logging and Aggregation for more information.

14.4.2. Existing security functionality¶

Do not disable SELinux, and do not disable Tower’s existing multi-tenant containment. Use Tower’s role-based access control (RBAC) to delegate the minimum level of privileges required to run automation. Use Teams in Tower to assign permissions to groups of users rather than to users individually. See Role-Based Access Controls in the Ansible Tower User Guide.

14.4.3. External account stores¶

Maintaining a full set of users just in Tower can be a time-consuming task in a large organization, prone to error. Ansible Tower supports connecting to external account sources via LDAP, SAML 2.0, and certain OAuth providers. Using this eliminates a source of error when working with permissions.

14.4.4. Django password policies¶

Tower admins can leverage Django to set password policies at creation time via AUTH_PASSWORD_VALIDATORS to validate Tower user passwords. In the custom.py file located at /etc/tower/conf.d of your Tower instance, add the following code block example:

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
        'OPTIONS': {
            'min_length': 9,
        }
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

For more information, see Password management in Django in addition to the example posted above.

Be sure to restart your Tower instance for the change to take effect. See Starting, Stopping, and Restarting Tower for detail.