Management interfaces

Management interfaces

It is necessary for administrators to perform command and control over the cloud for various operational functions. It is important these command and control facilities are understood and secured.

OpenStack provides several management interfaces for operators and tenants:

  • OpenStack dashboard (horizon)

  • OpenStack API

  • Secure shell (SSH)

  • OpenStack management utilities such as nova-manage and glance-manage

  • Out-of-band management interfaces, such as IPMI

Dashboard

The OpenStack dashboard (horizon) provides administrators and tenants with a web-based graphical interface to provision and access cloud-based resources. The dashboard communicates with the back-end services through calls to the OpenStack API.

Capabilities

  • As a cloud administrator, the dashboard provides an overall view of the size and state of your cloud. You can create users and tenants/projects, assign users to tenant/projects and set limits on the resources available for them.

  • The dashboard provides tenant-users a self-service portal to provision their own resources within the limits set by administrators.

  • The dashboard provides GUI support for routers and load-balancers. For example, the dashboard now implements all of the main Networking features.

  • It is an extensible Django web application that allows easy plug-in of third-party products and services, such as billing, monitoring, and additional management tools.

  • The dashboard can also be branded for service providers and other commercial vendors.

Security considerations

  • The dashboard requires cookies and JavaScript to be enabled in the web browser.

  • The web server that hosts the dashboard should be configured for TLS to ensure data is encrypted.

  • Both the horizon web service and the OpenStack API it uses to communicate with the back end are susceptible to web attack vectors such as denial of service and must be monitored.

  • It is now possible (though there are numerous deployment/security implications) to upload an image file directly from a user’s hard disk to OpenStack Image service through the dashboard. For multi-gigabyte images it is still strongly recommended that the upload be done using the glance CLI.

  • Create and manage security groups through dashboard. The security groups allows L3-L4 packet filtering for security policies to protect virtual machines.

Bibliography

OpenStack.org, ReleaseNotes/Liberty. 2015. OpenStack Liberty Release Notes

OpenStack API

The OpenStack API is a RESTful web service endpoint to access, provision and automate cloud-based resources. Operators and users typically access the API through command-line utilities (for example, nova or glance), language-specific libraries, or third-party tools.

Capabilities

  • To the cloud administrator, the API provides an overall view of the size and state of the cloud deployment and allows the creation of users, tenants/projects, assigning users to tenants/projects, and specifying resource quotas on a per tenant/project basis.

  • The API provides a tenant interface for provisioning, managing, and accessing their resources.

Security considerations

  • The API service should be configured for TLS to ensure data is encrypted.

  • As a web service, OpenStack API is susceptible to familiar web site attack vectors such as denial of service attacks.

Secure shell (SSH)

It has become industry practice to use secure shell (SSH) access for the management of Linux and Unix systems. SSH uses secure cryptographic primitives for communication. With the scope and importance of SSH in typical OpenStack deployments, it is important to understand best practices for deploying SSH.

Host key fingerprints

Often overlooked is the need for key management for SSH hosts. As most or all hosts in an OpenStack deployment will provide an SSH service, it is important to have confidence in connections to these hosts. It cannot be understated that failing to provide a reasonably secure and accessible method to verify SSH host key fingerprints is ripe for abuse and exploitation.

All SSH daemons have private host keys and, upon connection, offer a host key fingerprint. This host key fingerprint is the hash of an unsigned public key. It is important these host key fingerprints are known in advance of making SSH connections to those hosts. Verification of host key fingerprints is instrumental in detecting man-in-the-middle attacks.

Typically, when an SSH daemon is installed, host keys will be generated. It is necessary that the hosts have sufficient entropy during host key generation. Insufficient entropy during host key generation can result in the possibility to eavesdrop on SSH sessions.

Once the SSH host key is generated, the host key fingerprint should be stored in a secure and queryable location. One particularly convenient solution is DNS using SSHFP resource records as defined in RFC-4255. For this to be secure, it is necessary that DNSSEC be deployed.

Management utilities

The OpenStack Management Utilities are open-source Python command-line clients that make API calls. There is a client for each OpenStack service (for example, nova, glance). In addition to the standard CLI client, most of the services have a management command-line utility which makes direct calls to the database. These dedicated management utilities are slowly being deprecated.

Security considerations

  • The dedicated management utilities (*-manage) in some cases use the direct database connection.

  • Ensure that the .rc file which has your credential information is secured.

Bibliography

OpenStack.org, OpenStack End User Guide section. 2016. OpenStack command-line clients overview

OpenStack.org, Set environment variables using the OpenStack RC file. 2016. Download and source the OpenStack RC file

Out-of-band management interface

OpenStack management relies on out-of-band management interfaces such as the IPMI protocol to access into nodes running OpenStack components. IPMI is a very popular specification to remotely manage, diagnose, and reboot servers whether the operating system is running or the system has crashed.

Security considerations

  • Use strong passwords and safeguard them, or use client-side TLS authentication.

  • Ensure that the network interfaces are on their own private(management or a separate) network. Segregate management domains with firewalls or other network gear.

  • If you use a web interface to interact with the BMC/IPMI, always use the TLS interface, such as HTTPS or port 443. This TLS interface should NOT use self-signed certificates, as is often default, but should have trusted certificates using the correctly defined fully qualified domain names (FQDNs).

  • Monitor the traffic on the management network. The anomalies might be easier to track than on the busier compute nodes.

Out of band management interfaces also often include graphical machine console access. It is often possible, although not necessarily default, that these interfaces are encrypted. Consult with your system software documentation for encrypting these interfaces.

Bibliography

SANS Technology Institute, InfoSec Handlers Diary Blog. 2012. Hacking servers that are turned off

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