Kubernetes for IT Departments: Best practices, Security and Multi-Cloud

Kubernetes is rapidly establishing itself as an essential technology for companies seeking to modernize their IT infrastructures. According to a Gartner forecast, by 2025, over 85% of global enterprises will have deployed Kubernetes in production, a significant increase from 30% in 2020. This massive adoption underscores Kubernetes' importance in cloud platforms, enabling companies to gain flexibility and scalability.

Each major cloud provider offers managed Kubernetes services, with specific features tailored to various enterprise needs:

• Amazon Web Services (AWS): Amazon Elastic Kubernetes Service (EKS)
• Google Cloud Platform (GCP): Google Kubernetes Engine (GKE)
• Microsoft Azure: Azure Kubernetes Service (AKS)
• Oracle Cloud Infrastructure (OCI): Oracle Kubernetes Engine (OKE)

The choice of cloud provider for your Kubernetes service depends on several key factors:

• Your existing cloud provider preference
• Specific integration requirements with other cloud services
• The expertise available within your team to manage and optimize Kubernetes on that platform

However, with the increasing adoption of Kubernetes, the responsibility to ensure these deployments are both efficient and secure becomes increasingly important. It's crucial to follow best practices to manage and protect these complex environments. In this article, we will explore the best practices for using Kubernetes optimally, with a particular focus on security and the increasingly essential multi-cloud aspect.

1. Best Practices for Effective Kubernetes Management

To fully leverage Kubernetes, it's important to follow practices that facilitate the design, management, and optimization of your applications. Here are our top three tips to help you manage your Kubernetes clusters more effectively.

Application Design and Structuring

Your applications should be structured modularly. By dividing your applications into microservices, you simplify their management and make them easier to evolve. This allows you to update different parts of your application independently without risking breaking everything.

Additionally, by using labels and annotations, you can better organize and manage your resources.

• Labels help you categorise and filter objects in Kubernetes, making sorting and grouping operations simpler and more efficient. For example, you can label your pods by environment type, application and version. Kubernetes could automatically adjust the number of pods based on labels, according to workload and predefined rules.
• Annotations allow you to add specific information to objects. This additional information can be used by external tools, such as monitoring tools, security tools and backup tools. 

Resource Management

ConfigMaps are Kubernetes objects that separate application configuration from code. This means that configuration data (such as environment variables, configuration files, etc.) can be modified without having to redeploy the application. For example, you can store a database configuration in a ConfigMap, which your pods can then use. For sensitive information such as passwords or API keys, Secrets are the ideal tool, as they allow you to store and manage them securely.

It's also important to keep track of configuration changes by setting up version control (SVN, GitLab, etc.). That way, if something goes wrong, you can quickly revert to a previous version. 

Continuous Monitoring and Logging

Autoscaling, with Horizontal Pod Autoscaler, automatically adjusts the number of pods according to the workload, ensuring efficient use of resources without overloading your clusters.

The various CSPs offer native services such as Azure monitor for containers and Google Cloud Monitoring to monitor performance. They give you a real-time view of resource utilisation and any bottlenecks. If you want to control the distribution of workloads and node management, you can use the following strategies:

• Pod affinity: Imagine you have a mission-critical application that requires multiple pods to run on the same nodes to reduce latency. You can configure pod affinity using nodeAffinity, so that these pods are scheduled on specific nodes.
• Pod anti-affinity: Conversely, you might want to avoid two instances of the same application being deployed on the same node to improve resilience. Pod anti-affinity allows an application's pods to be dispersed across different nodes. 
• Taints and Tolerations: If you have dedicated nodes for specific workloads, you can use taints to ‘taint’ these nodes, making them inaccessible to the majority of pods except those with an appropriate ‘tolerance’. For example, a node with GPU capability could be marked with a taint gpu=true:NoSchedule, and only pods with a corresponding tolerance will be scheduled on that node, ensuring that GPU resources are not wasted by non-GPU workloads.

2. Securing Kubernetes

Kubernetes is becoming central to enterprise infrastructure. It is therefore essential to put in place robust security measures to prevent risks and vulnerabilities and to ensure that your applications and data are protected. Here are a few things you can do to strengthen the security of your Kubernetes clusters. 

Securing clusters

The first step in securing a Kubernetes cluster is to protect the network and ensure workload isolation. To do this, there are several key mechanisms in place:

• Network Policies allow you to control traffic between pods, limiting unwanted or malicious communications. They enable you to implement a ‘Zero Trust’ type security strategy by prohibiting any traffic that is not explicitly authorised.

• By using Namespaces, you can segment resources and users within the same cluster. Namespaces are often used to organise resources by environment (production, development) or by team.

• RBAC (Role-Based Access Control) lets you define exactly who can access what. 

• The use of pod security admissions and security contexts helps to restrict the actions that pods can take, thereby reducing the risk of security vulnerabilities being exploited. 

Data protection

Data protection is another pillar of security in Kubernetes. 
The cloud platform's native services make it possible to effectively secure your data, whether in transit or at rest. Encrypting data when it is transferred and when it is stored prevents it from being intercepted or read by unauthorised persons. 

Kubernetes allows sensitive information to be stored securely, but it's important to follow best practice to minimise risk, such as avoiding including it directly in pods or exposing it unnecessarily.
Finally, make sure that your data can be recovered in the event of a disaster or incident, while ensuring that backup processes are themselves secure. 

Container image security

Container images are another potential vector for attacks. To minimise the risks, use secure registries to store and distribute your images. These registries can be configured to automatically check for known vulnerabilities.

For example, you can use Google Container Registry (GCR) on GCP, Amazon Elastic Container Registry (ECR) on AWS, Azure Container Registry (ACR) on Azure, and Oracle Container Registry on OCI. Scanning tools such as Clair or Trivy are used in all these environments to identify and correct vulnerabilities in container images.

In addition, image signing and integrity checks, using tools such as Notary, ensure that only approved, unaltered images are deployed in your environment. 

Monitoring and auditing

Different Cloud Providers allow you to easily distribute control plane logs to native SIEM (Security Information and Event Management) systems such as AWS CloudWatch, Azure Monitor, Google Cloud Logging, or Oracle monitoring solutions. This centralised logging enables you to keep track of actions and changes within your cluster, which is important for investigating incidents and ensuring regulatory compliance.

Although there is no direct integration between pod logs running in managed Kubernetes services, and cloud logging tools, you can easily redirect these logs and metrics using native tools. This allows you to use this information to diagnose problems, create metrics filters or trigger notifications for specific events related to your applications. 

3. Kubernetes and multi-cloud interoperability

For businesses looking to adopt multi-cloud strategies, Kubernetes makes it easier to orchestrate and manage applications across multiple platforms. 
Deploying Kubernetes across hybrid and multi-cloud environments presents challenges, including managing connectivity, security, identities, centralised monitoring and configuration consistency. 
To meet these challenges, multi-cluster management tools such as Google's Anthos and Rancher stand out. 

Adopting these solutions offers a number of strategic advantages. Not only do they improve resilience and minimise the risk of dependency on a single cloud provider, they also optimise costs and meet regulatory constraints.

What's even more interesting is that these tools offer the ability to manage Kubernetes clusters spread across multiple clouds from a single interface, simplifying management and monitoring.

Kubernetes offers unprecedented flexibility and scalability for modern enterprises. By following the best practices presented in this article and drawing on the expertise of our teams, you can take full advantage of this technology to accelerate your digital transformation. Ready to modernise your infrastructure? Contact our DEEP experts for a personalised assessment of your needs and tailored support.

•    Source : https://www.gartner.com/en/newsroom/press-releases/2021-11-10-gartner-says-cloud-will-be-the-centerpiece-of-new-digital-experiences