Docker Architecture & Internals
5 Topics
1
Docker Architecture — Client, Daemon, Registry
Understand the components that make up the Docker platform.
A primary topic in DevOps and Infrastructure interviews to gauge your understanding of Docker's client-server communication, Unix sockets, and system-level security limits.
2
Docker Images and Layers — The Union File System
How overlay2 and copy-on-write compose filesystem layers.
Critical for understanding file storage footprints, overlay directory paths, and optimizing image build sizes during pipeline development.
3
Docker Hub and Image Registries — Public vs Private
Distributing image binaries and authenticating pulls securely.
Crucial for DevOps pipelines, deployment automation, security compliance, and Kubernetes private image pull integrations.
4
The Docker Build Cache — How It Works and How to Use It
Understanding layer caching rules to optimize build speeds.
A very common interview topic for SRE and platform roles. You must know how cache invalidation propagates and how to restructure Dockerfile instructions to minimize CI build times.
5
Docker Image Security — Scanning and Minimizing Attack Surface
Avoiding vulnerabilities, scanning with Trivy, and signing images.
High priority for modern DevSecOps SRE, and platform engineering roles. Expect questions on base image selection, CVE scanning tools, and non-root user enforcement.