DOCKER WORKFLOW & BEST PRACTICES

Docker Workflow: From Source Code to Secure Images

DOWNLOADING CONCEPT: 1. THE ANATOMY OF A DOCKERFILE...

↳A Dockerfile is the blueprint for creating a container image.
↳Each command creates a new, immutable 'layer' in the Overlay Filesystem.

■FROM alpine:latest: The base image. Always use minimal bases (Alpine, Distroless) to reduce attack surface.
■COPY . /app: Copies files from your host into the image.
■RUN npm install: Executes a command *during the build process* and bakes the result into a new layer.
■ENTRYPOINT ["node", "server.js"]: The exact binary that runs when the container starts. If this process crashes, the container dies.
■CMD ["--port", "8080"]: Default arguments passed to the ENTRYPOINT.

▲ LIVE INCIDENTA junior developer pushed a massive 2.5GB Docker image to ECR. The CI/CD security scanner blocked the deployment citing 45 Critical Vulnerabilities.

sre@arena:~/docker-workflow

sre@arena:~$ trivy image prod-backend:v1 | grep CRITICAL

Docker Workflow: From Source Code to Secure Images

1. The Anatomy of a Dockerfile

2. Layer Caching & Optimization

3. Multi-Stage Builds

4. The .dockerignore File

5. ARG vs ENV (Build vs Runtime)

6. Non-Root Users (Security)

7. The PID 1 Problem (Zombie Processes & Init)

8. Data Persistence (Volumes vs Bind Mounts)

9. Healthchecks

10. Image Scanning & Registries