It’s hard to ignore Kubernetes nowadays when discussing container orchestration thanks to its robustness and comprehensive features. It is capable of supporting even the most complex apps and services. Despite the wealth of features built into Kubernetes, the platform only provides a set of built-in authentication and authorization mechanisms which all administrators can configure and use—the thing is, in the information security world this is not enough. You need to optimize security yourself to take it next level.
With security becoming a primary concern in cloud deployment, knowing how to secure Kubernetes properly is a must. Putting a firewall layer on the host cluster is simply not enough, even though taking care of host security across all servers running Kubernetes containers can help.
It is recommended to use pre-built hardened images which have the minimum amount of packages needed for the cluster to run. The benefit of this is that the fewer packages the OS has, the fewer potential vulnerabilities are created, and thus, the overall potential attack surface area is reduced. Another thing to consider is keeping hosts up-to-date in terms of OS security patches and bug fixes.
So, how can we avoid getting hacked when using Kubernetes. Securing Kubernetes containers is a process that starts with the simplest things, which we’ll review in this article.
Key Security Elements to Cover
The host security mentioned earlier is a good start. Since Kubernetes doesn’t really manage the security of servers assigned to it, taking extra steps to properly secure your cloud environments is a must. When deploying your Kube cluster on cloud providers like AWS or GCP, you actually have plenty of security tools to use out of the box. Kubernetes requires additional configuration first—though this does increase your customization capabilities.
Next, you want to secure the container images. This means making sure that the codes running in each container are clean and free of malicious scripts. Also, it is recommended to keep base images up-to-date in terms of security patches. A container image scanner can help automate the process of scanning codes and warning administrators when faulty codes added to harm the cluster are found. This should be part of the Continuous Integration (CI) system where images that don’t pass the scan and would make the build process fail are prevented from being available for deployment.
Pod-to-pod communications should be the next thing you focus on. Pods communicate with each other and act as the building blocks for a complex app. Pods regularly exchange requests and responses, stream data for different purposes, and deliver key commands that may include sensitive information. Adding TLS to all pod-to-pod communications is a necessity.
It is also desirable to implement Kube network policies or similar; a set of rules which controls how pods are allowed to communicate which each other.
Lastly, incorporate better user and identity management using least-privilege access control. Proper security configurations for each user—including system user—will help secure the entire environment better. Make sure all users follow the predefined security policies and best practices too.
Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS)
Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) are the next layers of security to add to your Kubernetes setup. While the two may look similar, IDS and IPS are two separate functions that serve specific purposes.
IPS as a layer focuses more on network traffic. An IPS layer will monitor and analyze traffic for signs of malicious activity. It can identify potential attackers and the attacks they are trying to launch, and then take the necessary steps to block those potential attackers. In essence, it prevents attacks as early as possible using known security threats.
IDS, on the other hand, focuses more on the traffic itself; a good Intrusion Detection System identifies known cyber threats and a wide range of attacks, and carefully analyzes server activities based on these identifiers. When malicious activities are detected, IDS will also take steps to prevent worse attacks from hitting the server, including notifying the server administrator.
IDS is the more suitable tool for monitoring, while IPS is the tool to use for better system control. The two instruments can be used in tandem to provide sufficient protection to your containers and the microservices running in them.
Kubernetes Security Vendors
These security vendors are definitely worth looking into to help enhance and optimize your Kubernetes security:
- Twistlock is perhaps the most popular security suite for Kubernetes. It offers a long list of security features, signaling its comprehensive approach in container security. The vendor even offers real-time prevention and granular access control across the entire environment.
- Aqua is more famous for its serverless security solution, but the company’s Kubernetes security is not to be taken lightly. It doesn’t just add security layers to existing pods and containers; it also enables developers to set up secure container images and environments from the start.
- Capsule8 requires no kernel or kernel module, so it is very robust and capable when used outside the operating system’s kernel. This makes Capsule8 very suitable for DevOps teams who want to stop worrying about server security. It also performs really well, making it suitable for Ops.
- Falco first became popular for its Container Native Runtime Security. Since it was first introduced, Falco has gotten very robust and Kubernetes-aware. It is a great way to secure your runtimes, especially since every tool that Falco offers is designed with developers in mind.
- Threat Stack is the last vendor on our list, but it is far from being the least recommended. Threat Stack adds observability and security-through-data to better secure your cloud environment. It is also regarded as one of the best when it comes to performance under heavy load.
Which vendor is right for your cloud environment? The answer depends highly on the kind of apps you want to run and the way you configure your cloud. These tools will certainly make setting up sufficient security layers for your Kubernetes environment easy.
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