3. Maintaining Kubernetes

Date: 2023-12-20

Status

Accepted

Context

We need to decide how to deploy our services to Kubernetes and maintain our Kubernetes clusters. Previously, we used Kubespray for cluster maintenance but needed a more efficient solution. We also required a seamless method for deploying services to Kubernetes.

Decision

Kubernetes Cluster Maintenance

We have transitioned from Kubespray to Talos for maintaining our Kubernetes clusters. Talos is a modern OS designed specifically for Kubernetes, providing a minimal, immutable, and secure environment. We have also integrated the GitLab Agent in our Kubernetes clusters for improved CI pipeline connectivity.

Deployment of Services

For the deployment of our services to Kubernetes, we will use the Helm package manager. This approach ensures efficient management of Kubernetes applications.

Hardware Configuration

@startuml k8s_nodes

' Define KubernetesPuml for URL inclusion
!define KubernetesPuml https://raw.githubusercontent.com/dcasati/kubernetes-PlantUML/master/dist

' Include common Kubernetes components
!includeurl KubernetesPuml/kubernetes_Common.puml
!includeurl KubernetesPuml/kubernetes_Context.puml

' Include specific components for nodes
!includeurl KubernetesPuml/OSS/KubernetesNode.puml

' Include C4 model
!includeurl https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml

skinparam backgroundColor #FEFEFE
skinparam handwritten false

left to right direction

' Define C4 Context
LAYOUT_TOP_DOWN()

System_Boundary(k8s_cluster, "K8s Cluster") {
    ' Define Nodes
    KubernetesNode(talos_bxi_ihe, "talos-bxi-ihe\nStatus: Ready\nRoles: <none>\nAge: 78d\nVersion: v1.31.2", "#ffcccc")
    KubernetesNode(talos_coj_emd, "talos-coj-emd\nStatus: Ready\nRoles: <none>\nAge: 78d\nVersion: v1.31.2", "#ccffcc")
    KubernetesNode(talos_dks_th8, "talos-dks-th8\nStatus: Ready\nRoles: <none>\nAge: 78d\nVersion: v1.31.2", "#ccccff")
}

@enduml

CI/CD

We will use the GitLab CI/CD to deploy our services to Kubernetes.

GitOps

We will use ArgoCD to manage our Kubernetes cluster.

• Introduction to Continuous Delivery and GitOps using Argo CD

Secrets

We use SOPS to manage our secrets.

Consequences

• Enhanced Cluster Security and Simplification: Talos improves security and simplifies Kubernetes operations.
• Efficient Updates and Rollbacks: Talos offers reliable, minimal-downtime update and rollback processes.
• Improved CI Integration: GitLab Agent enables automated, secure CI connections.
• GitOps Efficiency: ArgoCD enhances cluster management via GitOps.
• Secure Secret Management: SOPS ensures secure handling of secrets.

References

1. Talos Systems: For detailed information about Talos, visit their official website: Talos Systems.
2. GitLab Kubernetes Agent: To learn more about the GitLab Agent for Kubernetes, refer to the official documentation at GitLab Kubernetes Agent.