Testing
Testing with Coolify: Self-Hosted Deployment Verification and Docker Testing
Coolify has emerged as the leading self-hosted alternative to platforms like Heroku and Render.
Docker
Latest
Testing
seccomp Profiles: Writing and Testing Syscall Filters for Containers
Every system call a container makes is an attack surface. seccomp (Secure Computing Mode) lets you define exactly which syscalls a container is allowed to make — and kill or log anything outside that list. The challenge is writing profiles that are tight enough to restrict attacker behavior but permissive enough
Testing
Local Email Testing with MailHog in Docker: Capturing, Inspecting, and Asserting Emails
MailHog is an open-source local SMTP server that captures all outgoing emails and exposes them via a web UI and HTTP API. No signups, no internet connection required, and no risk of emails reaching real users. This guide covers running MailHog in Docker, asserting on captured emails via its
Chaos Engineering
Pumba: Docker Container Chaos Testing Guide
Pumba is a chaos testing tool for Docker containers. It kills containers, pauses them, and injects network failures using Linux tc (traffic control) — directly on your Docker host or inside Docker Compose environments. If you run microservices locally with Docker Compose or test in Docker-based CI environments, Pumba is
Security Testing
Trivy: Container Image and IaC Security Scanning
Trivy is an open-source vulnerability scanner that covers container images (OS packages and application dependencies), Kubernetes manifests, Terraform, Dockerfiles, and secrets. It's fast, requires no setup beyond installation, and produces structured JSON or table output. Use Trivy in CI to block builds with critical vulnerabilities before they
Testing
Testing Container Images: Trivy, Grype, and Structure Tests
Shipping a container image without testing it is like deploying code without running tests.
Integration Testing
Testcontainers Python: Integration Tests with Real Services
Mocking database calls in Python tests creates a false sense of security. testcontainers-python spins up real PostgreSQL, Redis, and MongoDB containers via Docker during your pytest run, giving you genuine integration coverage without managing external services. Key Takeaways testcontainers-python integrates with pytest through fixtures. Define containers in conftest.
Integration Testing
Testcontainers for Node.js: Database Integration Tests Done Right
Node.js integration tests that mock PostgreSQL and Redis test your assumptions, not your code. testcontainers starts real database containers during your Jest run and tears them down after. Your tests talk to the actual services — no mocks, no drift, no surprises. Key Takeaways testcontainers/node works with Jest, Vitest,
Docker
How to Test Docker Containers and Dockerized Applications
Shipping a Docker image without testing it is like deploying code without tests — the problems show up in production. Docker containers need their own testing layer: build tests, container smoke tests, integration tests, and security scans. Here's how to build that layer. Key Takeaways Test at four levels:
CI/CD
Container Testing in CI/CD: GitHub Actions + Docker Best Practices
Container-based integration tests are slower in CI than you want them to be — mostly because of image pulls, layer rebuilds, and serial test execution. Fix that with layer caching, GitHub Actions service containers, and parallel job splitting. Here's exactly how. Key Takeaways GitHub Actions service containers are