Kubernetes’ complexity necessitates substantial effort for its configuration and management. Kubernetes workloads, especially those used in a production environment, need to be protected by implementing security best practises. This is because fixing it will necessitate addressing critical architecture flaws and platform reliance.
The first step is to turn on Kubernetes’ RBAC feature (RBAC)
With RBAC’s help, you can specify which users have access to the Kubernetes API and what privileges they have there. RBAC is normally enabled by default on Kubernetes versions 1.6 and later (later on some hosted Kubernetes providers). When using Kubernetes with its new RBAC feature, you must turn off the older Attribute Based Access Control first. Kubernetes’s integration of authorization controllers is to blame (ABAC).
Read our in-depth tutorial on Kubernetes RBAC to learn more
Second, have a third-party authentication service be used by the API server
Integrating a third-party authentication provider into the kubernetes best practices environment is highly recommended (e.g. GitHub). This not only provides extra security features like multi-factor authentication, but also guarantees that kube-apiserver does not change when users are added or removed. If at all possible, you should prevent the API server from being responsible for user management. Connectors for OAuth 2.0, such as Dex, are also at your disposal.
Protect etcd with a firewall, encryption, and Transport Layer Security (TLS)
etcd stores the cluster state and secrets, making it a prime target for attackers and making it a vulnerable resource for the cluster. If a hacker manages to gain access to etcd, they can effectively take over the entire cluster. As with write access, read access is dangerous because it can be used by malicious users to gain access to even more sensitive information.
Enable encryption of secrets while the etcd is idle:
However, etcd’s encryption is disabled by default despite its importance to the system’s safety. Using the kube-apiserver process and passing it the -encryption-provider-config argument will get things working. To enable encryption in the configuration, you’ll need to select a provider and define your private keys. Please consult the manual for more details.
Kubernetes Node Isolation
Whenever possible, keep Kubernetes nodes isolated from the internet by connecting them to a private network. You should avoid connecting directly to the corporate network if at all possible.
In order for this to work with Kubernetes, the separation of control and data traffic is a prerequisite. In the absence of both of these conditions, the data and control planes will use the same pipe, and unrestricted access to the data plane will inevitably lead to unrestricted access to the control plane. In a perfect world, the network access control list on each node would be set up to only allow connections from the master node on a specific port (ACL).
Monitor network activity and place limits on data and voice transmissions
Containerized applications typically make extensive use of cluster networks. Monitor the current network traffic and compare it to the traffic allowed by the Kubernetes network policy to spot unusual forms of communication and gain a deeper understanding of how your application operates.
Take advantage of whitelisting processes
Whitelisting processes is an effective way to identify those that should not be active. The first step is to keep an eye on the app while it’s running normally to figure out which processes are keeping it going. Then, use this approved-users-only list as a filter for your future app-related actions.
Seven, turn on the option to record audit trails
Make sure audit logging is enabled and that API calls, and particularly failed authentication attempts, are being closely monitored for anything that might be suspicious. All of these log entries show a “Forbidden” status message. It’s possible that an attacker is trying to use stolen credentials if authorization fails.
