Blog
Practical, command-level guides for system administrators and DevOps engineers — Linux, networking, containers, cloud, databases, virtualization and telecom.
Topics
Latest articles
auditd Basics
auditd records who did what at the syscall level — file access, config changes, privilege use. Here's how to write useful rules without drowning the disk.
September 16, 2026SSH Server Hardening
The sshd_config settings that matter, in priority order — key-only auth first — plus how to apply them without locking yourself out of the box.
September 16, 2026Finding What Is Using a Port on Linux
The three commands that answer 'address already in use', including the container and namespace cases that trip people up.
September 16, 2026Redis Streams as a Work Queue
Redis Streams give you a persistent, consumer-group log — enough for many work-queue needs without adding Kafka or RabbitMQ. Here's the commands and the reliability model.
September 15, 2026Kustomize Basics
Kustomize customizes plain YAML with overlays instead of templating. Here's bases vs overlays, the patch types, generators, and the gotchas around name suffixes.
September 13, 2026EKS vs Self-Managed Kubernetes
EKS runs the control plane for you; you still own nodes, networking, and add-ons. Here's the division of responsibility, the node options, and when self-managed is worth it.
September 11, 2026AWS Step Functions Basics
Step Functions orchestrates multi-step workflows as a state machine with built-in retries, error handling, and visual history. Here's the states, the two types, and when to use it.
September 10, 2026Diameter Routing Agents in Depth
A Diameter Routing Agent is the STP of the LTE/IMS world — it routes messages by realm and application so nodes don't need full-mesh peering. Here's the agent types and routing.
September 8, 2026The AWS Load Balancer Controller
On EKS, the AWS Load Balancer Controller turns Ingress objects into ALBs and LoadBalancer Services into NLBs. Here's target types, ALB sharing, and the IAM/subnet-tag gotchas.
September 7, 2026How NAT Actually Works
NAT is a stateful rewrite plus a connection-tracking table. What that table holds, why it fills up, and the protocols NAT quietly breaks.
September 7, 2026MySQL User Management and Grants
MySQL identity is user + host, and grants apply at several scopes. Here's creating least-privilege app accounts, roles, and reading SHOW GRANTS.
September 1, 2026Prometheus Cardinality Management
Every unique label combination is a time series, and Prometheus holds them all in memory. A label with a request ID in it can OOM your Prometheus — here's how to find and fix it.
August 31, 2026