Actionable walkthroughs on containerization, multi-stage builds, microservices orchestration, container networking, and DevOps pipelines.
A private container registry is the backbone of any serious container workflow. Public registries like Docker Hub are convenient for open-source images, but they impose pull rate limits, expose your image names to the world, and create a dependency on an external service that can go down or change its terms. For teams building proprietary…
A private registry running without authentication and TLS is a liability. Anyone who can reach the port can push malicious images, overwrite your tags, or pull your proprietary code. Anyone on the network path can read every byte of your images in transit. And even a secured registry will eventually fill its disk with orphaned…
Docker Swarm is Docker’s native clustering and orchestration solution, built directly into the Docker Engine. Unlike Kubernetes, which is a separate system that you install on top of your infrastructure, Swarm mode is activated with a single command and requires no additional software. This integration is both its greatest strength and its most limiting constraint:…
A Docker Swarm service is not a container. It is a declaration of intent. When you create a service, you are telling the Swarm manager what the cluster should look like—how many instances of an image should be running, how they should be networked, and what policies govern their lifecycle. The manager then works continuously…
Docker Swarm overlay networks solve a fundamental problem: how do containers running on different physical hosts communicate as if they were on the same machine? The answer has two layers. The first is the overlay network itself—a virtual Layer 2 network that spans all Swarm nodes, with container traffic encapsulated in UDP datagrams through the…
Docker Swarm provides two native cluster objects for delivering data to services: secrets for sensitive information and configs for non-sensitive configuration. Both solve the same fundamental problem—how to inject data into containers without baking it into images or passing it through environment variables—but they differ in one critical dimension: secrets are encrypted at rest in…
A homelab or small server deployment that runs on a single machine is not highly available. When that machine reboots, every service goes down. When a disk fails, every container is lost. The purpose of building a Swarm cluster for a homelab is not to match the scale of a cloud provider—it is to eliminate…
Docker Compose and Kubernetes both run containers, but they are built on fundamentally different assumptions about what a deployment is. Compose assumes a single host, a single Docker Engine, and a developer who wants to start a multi-container application with one command. Kubernetes assumes a cluster of machines, a control plane that continuously reconciles desired…
kompose is the official Kubernetes project for converting Docker Compose files into Kubernetes or OpenShift manifests . Its purpose is mechanical translation: it reads the services, volumes, and port definitions in a compose.yaml file and produces Deployments, Services, and PersistentVolumeClaims that the Kubernetes API can accept . The tool is explicitly designed as a starting…
Docker Engine has always been a layered system. When you run docker run, the CLI talks to dockerd, which delegates to containerd, which in turn uses runc to create the actual container process . The containerd layer is the core runtime: it manages images, snapshots, and container lifecycle, and it is the component that Kubernetes…