Kubernetes configuration management

Broadly speaking, configuration management is the engineering practice of establishing policies regarding configurations and ensuring that those policies are applied consistently across the entire organization, throughout the application life cycle. Configurations are a critical part of managing security risk in cloud-native applications, especially because many default configurations for containers and Kubernetes are not secure. Misconfigurations are the most common source of security risk in containerized applications running on Kubernetes.

Configuration management must be automated, with guardrails managed centrally so that individual developers or operators are not responsible for manually configuring workloads. These guardrails should be based on organizational security policies.

According to Gartner, 95% of cloud security failures are caused by human error. As applications become increasingly complicated, running on distributed systems in containers and Kubernetes, the risk of misconfigurations expands. In the absence of a centralized configuration management tool, it is nearly impossible for organizations to ensure that configuration policies are consistently applied. For companies with a multi-cloud or hybrid cloud setup, getting configuration right consistently is even more challenging, because each environment requires a different set of configurations. There’s also a persistent skills gap among developers and operators who aren’t always aware of best practices for secure configuration.

In many cases the easiest way for developers to set configurations for their applications to run is also the least secure, such as allowing root access, giving admin privileges or setting very high resources limits. With the right tools, configuration management can be integrated into the DevOps workflow so it doesn’t slow down development velocity. Doing so is a best practice, because it eliminates the tension between releasing quickly and securing the workload’s configurations.

Configuration management should include a way to both get visibility into configurations as well as put guardrails on what configurations are allowed, so that insecure builds or risky deployments can be failed automatically. Organizations need to get a single pane of glass to see all relevant configurations across containers and Kubernetes and be alerted to potentially risky configurations.

The cornerstones of configuration management for containers and Kubernetes are the following:

  • Role-based access controls (RBAC). Organizations need to find overly permissive configurations and/or unnecessary roles.
  • Secrets. A good configuration management tool can proactively limit access to secrets.
  • Policy-based assessments. Setting organizational security policies is a crucial part of any security posture, and there should be a way to check deployments against those pre-determined policies.
  • Privileges. Privileges should be assigned based on least-privileged-access principles.
  • Resource limits. Both containers and Kubernetes clusters should have limits on the CPU and memory available.
  • Network policies. Network policies should limit the communication between parts of the application as much as possible to limit potential damage if a container is compromised.

The simplest way to start with configuration management is to follow industry-accepted best practices like the CIS Benchmarks. As the organization’s adoption of containers advances, creating organizational governance policies around configuration management is a best practice. Configuration management should cover both configurations for containers and Kubernetes, as configurations have to be managed appropriately in both places to ensure a strong security posture.

Last updated: Sep-17-2020