February 22, 2026The most dangerous thing an agent can do is confidently produce a deliverable based on wrong assumptions. An agent that assumes x86_64 when the target is ARM64, that assumes PostgreSQL 14 behavior when the target runs 15, or that assumes AWS IAM patterns when the target is Azure – that agent produces a runbook that will fail in ways the human did not expect and may not understand.
February 22, 2026Devcontainers provide disposable, reproducible development environments that run in a container. You define the tools, extensions, and configuration in a .devcontainer/ directory, and any compatible host – GitHub Codespaces, Gitpod, VS Code with Docker, or the devcontainer CLI – builds and launches the environment from that definition.
For infrastructure validation, devcontainers solve a specific problem: giving every developer and every CI run the exact same set of tools at the exact same versions, without requiring them to install anything on their local machine. A Kubernetes devcontainer includes kind, kubectl, helm, and kustomize at pinned versions. A Terraform devcontainer includes terraform, tflint, checkov, and cloud CLIs. The environment is ready to use the moment it starts.
February 22, 2026A trace represents a single request flowing through a distributed system. It is identified by a 128-bit trace ID. A span represents one unit of work within that trace – an HTTP handler, a database query, a message publish. Each span has a name, start time, duration, status, attributes (key-value pairs), and events (timestamped annotations). Spans form a tree: every span except the root has a parent span ID.
February 22, 2026EKS bridges two identity systems: AWS IAM and Kubernetes RBAC. Understanding how they connect is essential for both granting pods access to AWS services and controlling who can access the cluster.
IRSA lets Kubernetes pods assume IAM roles without using node-level credentials. Each pod gets exactly the AWS permissions it needs, not the broad permissions attached to the node role.
February 22, 2026EKS networking differs fundamentally from generic Kubernetes networking. Pods get real VPC IP addresses, load balancers are AWS-native resources, and networking decisions have direct cost and IP capacity implications.
The AWS VPC CNI plugin assigns each pod an IP address from your VPC CIDR. Unlike overlay networks (Calico, Flannel), pods are directly routable within the VPC. This means security groups, NACLs, and VPC flow logs all work with pod traffic natively.
February 22, 2026Amazon EKS runs the Kubernetes control plane for you – managed etcd, API server, and controller manager across multiple AZs. You are responsible for the worker nodes, networking configuration, and add-ons.
eksctl is the fastest path for a working cluster. It creates the VPC, subnets, NAT gateway, IAM roles, node groups, and kubeconfig in one command:
eksctl create cluster \
--name my-cluster \
--region us-east-1 \
--version 1.31 \
--nodegroup-name workers \
--node-type m6i.large \
--nodes 3 \
--nodes-min 2 \
--nodes-max 10 \
--managedFor repeatable setups, use a ClusterConfig file:
February 22, 2026EKS failure modes combine Kubernetes problems with AWS-specific issues. Most fall into a handful of categories: IAM permissions, networking/security groups, missing tags, and add-on misconfiguration.
Symptoms: kubectl get nodes shows fewer nodes than expected. ASG shows instances running, but they never register.
The most common cause. Worker nodes authenticate via aws-auth. If the node IAM role is not mapped, nodes are rejected silently.
February 22, 2026Ephemeral clusters exist for one purpose: validate something, then disappear. They are not staging environments, not shared dev clusters, not long-lived resources that someone forgets to turn off. The operational model is strict – create, validate, destroy – and the entire sequence must be automated so that destruction cannot be forgotten.
The cost of getting this wrong is real. A three-node EKS cluster left running over a weekend costs roughly $15. Left running for a month, $200. Multiply by the number of developers or CI pipelines that create clusters, and forgotten ephemeral infrastructure becomes a significant budget line item. Every template in this article includes auto-destroy mechanisms to prevent this.
February 22, 2026etcd is the backing store for all Kubernetes cluster state. Every object – pods, services, secrets, configmaps – lives in etcd. If etcd is unhealthy, your cluster is unhealthy. If etcd data is lost, your cluster is gone. Managed Kubernetes services (EKS, GKE, AKS) handle etcd for you, but self-managed clusters require you to operate it directly.
All etcdctl commands below require TLS flags. Set these as environment variables to avoid repeating them:
February 22, 2026This is the definitive operational plan for taking a fresh Kubernetes cluster and making it production-ready. Each phase builds on the previous one, with verification steps between phases and rollback notes where applicable. An agent should be able to follow this sequence end-to-end.
Estimated timeline: 5 days for a single operator. Phases 1-2 are blocking prerequisites. Phases 3-6 can partially overlap.
Everything else depends on a healthy cluster with proper namespacing and storage. Do not proceed until every verification step passes.