Infrastructure

RHEL in Practice #4 Monitoring: Cockpit, PCP
11 min read

RHEL in Practice #4 Monitoring: Cockpit, PCP

The fourth post in the RHEL in Practice track. Once you have web, DB, and containers running, it is time to look at what is actually happening on top of them. This post walks through one full cycle: standing up the Cockpit web console for browser-based server management and Performance Co-Pilot (PCP) for collecting and recording performance metrics on RHEL, then wiring the two together to view performance graphs. It also covers when to reach for the basic commands like top, ss, journalctl, and sar.

AWS Certified Cloud Practitioner (CLF-C02) #5 Domain 2-2 Compliance — Governance, AWS Artifact, GDPR/HIPAA
9 min read

AWS Certified Cloud Practitioner (CLF-C02) #5 Domain 2-2 Compliance — Governance, AWS Artifact, GDPR/HIPAA

The second half of Domain 2. What AWS compliance certifications (SOC, ISO, PCI DSS, HIPAA, FedRAMP, GDPR) actually mean, how to pull certification documents through AWS Artifact, where governance tools (CloudTrail, Config, Organizations SCP) and security operations tools (GuardDuty, Inspector, Macie, Security Hub) sit, and finally data encryption (at rest and in transit) together with KMS and CloudHSM. In #6 we head into Domain 3 — Compute and Storage at 34% of the exam weight.

AWS in Practice #4: IaC — Terraform Fundamentals
10 min read

AWS in Practice #4: IaC — Terraform Fundamentals

Why IaC, Terraform shape of provider / resource / state, team collaboration with S3 + DynamoDB backend, environment separation through modules, and the flow of code-ifying the #1–#3 infrastructure line by line.

K8s Practice #1: EKS Cluster Setup — Terraform / eksctl / IRSA / Addons
12 min read

K8s Practice #1: EKS Cluster Setup — Terraform / eksctl / IRSA / Addons

The first post in the K8s Practice series. We follow the path of building a real operational cluster rather than a toy abstraction. Defining the VPC and EKS cluster with Terraform, setting up node groups and IRSA, laying on the essential addons (VPC CNI, CoreDNS, kube-proxy, EBS CSI), and comparing eksctl as a faster setup option along the way. The starting point for the imaginary service myshop-api used throughout the 6-post series.

RHEL in Practice #3: Container Workloads — Podman, systemd (quadlet)
9 min read

RHEL in Practice #3: Container Workloads — Podman, systemd (quadlet)

The third post in the RHEL in Practice track. Putting the web and DB we stood up by hand in #1 and #2 back up as containers, we organize the operational flow of Podman, RHEL's standard container engine. Image pull and run, volumes and port mapping, rootless containers, and integrating containers as systemd services with quadlet for automatic startup at boot — all in one cycle.

AWS Certified Cloud Practitioner (CLF-C02) #4 Domain 2-1 Security — Shared Responsibility Model and IAM Basics
9 min read

AWS Certified Cloud Practitioner (CLF-C02) #4 Domain 2-1 Security — Shared Responsibility Model and IAM Basics

The first half of Domain 2 (30%), the largest-weighted domain of the CLF-C02 exam. Where the responsibility line falls between AWS and the customer (and how that shifts with the service model), the four IAM essentials — users, groups, roles, and policies — and how they differ, operating principles for MFA and access keys, and a root user guide that often appears as an exam trap. The next post #5 continues with compliance certifications, AWS Artifact, and encryption.

AWS in Practice #3: CI/CD — GitHub Actions + ECR + ECS
10 min read

AWS in Practice #3: CI/CD — GitHub Actions + ECR + ECS

GitHub Actions without access keys via OIDC, ECR push, automatic Task Definition updates, ECS Service rolling deployments, deployment circuit breakers and auto-rollback, and a touch of CodeDeploy blue/green — a deployment flow that ends with a single git push.

K8s Advanced #6: GitOps — ArgoCD / Flux
11 min read

K8s Advanced #6: GitOps — ArgoCD / Flux

The last post in the K8s Advanced series. GitOps — the operational model where the source of truth for manifests lives in git and a controller inside the cluster watches git to sync automatically. Covers the difference between push and pull models, ArgoCD's Application CRD and sync wave, Flux's Source / Kustomization / HelmRelease, directory structure patterns, and how to safely store secrets in git via Sealed Secrets / External Secrets. Also includes a 6-post K8s Advanced retrospective and a preview of the next track, K8s Practice.

RHEL in Practice #2: Database Operations — PostgreSQL on RHEL
9 min read

RHEL in Practice #2: Database Operations — PostgreSQL on RHEL

The second post in the RHEL in Practice track. Having stood up the web tier, we move to the data tier behind it: installing and initializing PostgreSQL via RHEL's AppStream modules. We cover the data directory and SELinux context, postgresql.conf / pg_hba.conf settings and the firewalld opening for remote access, and everything from creating users and databases to backup, recovery, and diagnosis when you get stuck — all from a real operations perspective.

AWS Certified Cloud Practitioner (CLF-C02) #3 Domain 1-2 Cloud Design — The Six Well-Architected Pillars
9 min read

AWS Certified Cloud Practitioner (CLF-C02) #3 Domain 1-2 Cloud Design — The Six Well-Architected Pillars

The second half of CLF-C02 Domain 1. We unpack the six pillars of the AWS Well-Architected Framework — Operational Excellence, Security, Reliability, Performance Efficiency, Cost Optimization, and Sustainability — and organize the design principles and exam-scenario mappings for each. We also fix the common mistake of memorizing only five pillars and forgetting Sustainability, which was added in December 2021. From #4 onward we head into Domain 2 Security, the 30% giant.

AWS in Practice #2: RDS Integration and Migration Operations
10 min read

AWS in Practice #2: RDS Integration and Migration Operations

RDS Postgres Multi-AZ inside the VPC, Security Group design, password injection through Secrets Manager, the operational side of Alembic / Django migrations, and blue/green-compatible migration patterns.

K8s Advanced #5: Observability — Prometheus / Grafana / Loki / OpenTelemetry
10 min read

K8s Advanced #5: Observability — Prometheus / Grafana / Loki / OpenTelemetry

Operational cluster observability is composed of three axes — metrics, logs, and traces. The K8s standard stack for each axis is nearly settled. Metrics with Prometheus + kube-state-metrics + node-exporter, logs with Loki (or EFK), traces with OpenTelemetry, visualization with Grafana, alerting with Alertmanager. This post organizes the three-axis model, the standard components for each axis, and operational principles like cardinality, retention period, and alert design — all in one cycle.