kubernetes | farishuskovic.dev

Optimistic Concurrency and Other controller-runtime Gotchas

March 18, 2026

#kubernetes #go

The Kubernetes API uses optimistic concurrency control. If you don’t understand resourceVersion, your controller will fight itself.

Custom Cache Indices in controller-runtime

February 10, 2026

#kubernetes #go

The controller-runtime cache can list resources by namespace and name. Custom indices let you query by any field.

Leader Election in Kubernetes Controllers

January 14, 2026

#kubernetes #go

You run two replicas of your controller for availability. Without leader election, both try to reconcile the same resources at the same time.

Finalizers in Kubernetes Controllers

December 1, 2025

#kubernetes #go

Deletion in Kubernetes is instant — unless a finalizer says otherwise. Here’s how to run cleanup logic before a resource disappears.

Owner References and Secondary Watches

October 7, 2025

#kubernetes #go

Your controller creates a Deployment. The Deployment changes. How does your controller find out? Owner references and secondary watches.

The Status Subresource in Kubernetes Controllers

September 22, 2025

#kubernetes #go

Spec is what the user wants. Status is what the controller observes. Keeping them separate is how you avoid infinite reconcile loops.

Predicates and Event Filtering in controller-runtime

August 12, 2025

#kubernetes #go

Your controller doesn’t need to reconcile every change. Predicates let you filter out the noise.

Custom Resource Definitions with controller-runtime

June 3, 2025

#kubernetes #go

Kubernetes ships with Pods, Deployments, and Services. CRDs let you teach it your own types.

Writing Your First Controller with controller-runtime

May 20, 2025

#kubernetes #go

The reconciler pattern makes sense in theory. Here’s what it looks like in code.

The Reconciler Pattern

April 8, 2025

#kubernetes #go

A Kubernetes controller doesn’t respond to events — it reconciles state. That distinction changes how you think about everything.

Range-over-Func: Custom Iterators in Go

December 3, 2024

#go

Go 1.23 made functions valid range targets. You can now iterate over anything — not just slices, maps, and channels.

Structured Logging with log/slog

September 10, 2024

#go

Go 1.21 added log/slog to the standard library. Structured logging without a dependency.

Building a TCP Reverse Shell in Go

July 16, 2024

#go #security

A reverse shell is one of the simplest networking programs you can write. It’s also one of the most instructive — you’ll touch TCP, process execution, I/O piping, and terminal handling in under 100 lines.

Error Wrapping in Go

May 8, 2024

#go

Go errors are values. Wrapping them adds context without losing the original cause.

HTTP Updates to Go's Standard Library

March 12, 2024

#go

Go 1.22 added path parameters to net/http. You no longer need a third-party router for basic routing.

SSH Local Forwarding to Cloud SQL via Cloud SQL Proxy

March 14, 2023

#gcp #databases #devops

You need to hit a Cloud SQL instance from your laptop. It’s in a private VPC with no public IP. Here’s how to get there.

Cloud Run vs GKE: When to Use Each

November 8, 2022

#gcp #devops

Both run containers. The question is how much of the infrastructure you want to own.

Connection Pooling: Why Your App Shouldn't Manage Its Own Connections

August 16, 2022

#databases #devops

Opening a database connection is expensive. Opening one per request is a problem. Opening one per query is a disaster.

Resource Requests and Limits in Kubernetes

May 10, 2022

#kubernetes #devops

Requests tell the scheduler where to place your pod. Limits tell the runtime when to stop it.

Generics

March 20, 2022

#go

Write the function once. Let the compiler figure out the types.

Database Tooling for Go

February 8, 2022

#databases #go

Four tools, four approaches. Here’s how golang-migrate, goose, sqlc, and GORM compare — and when to use each.

FIFO Queues in Go

November 3, 2021

#go

Go doesn’t ship with a queue. Here’s how to build one that fits your use case.

Liveness vs Readiness Probes: What Breaks When You Get Them Wrong

September 14, 2021

#kubernetes #devops

A pod that’s running isn’t necessarily a pod that’s ready. Kubernetes uses two separate probes to tell the difference.

Database Transactions and Isolation Levels

June 22, 2021

#databases

Transactions are how databases keep their promises. Isolation levels determine how strict those promises are.

Docker Layer Caching: How It Works and How to Use It

July 22, 2020

#docker #devops

Every instruction in your Dockerfile creates a layer. Change one, and everything after it rebuilds. This isn’t a bug — it’s the mechanism. Learn to use it.