Continuous Integration and Continuous Deployment transform how teams ship software. Instead of dreading deployments as high-risk events, CI/CD makes them routine. Here's how to implement pipelines that actually improve your development workflow.
What CI/CD Really Means
Continuous Integration is the practice of merging code changes frequently;at least daily;and validating each merge with automated builds and tests. The goal is catching integration problems early when they're cheap to fix.
Continuous Deployment extends this by automatically deploying every change that passes testing to production. Continuous Delivery is the slightly less aggressive variant where code is always deployable, but the actual deployment requires manual approval.
The distinction matters less than the underlying principle: automation reduces risk by making deployments smaller and more frequent.
Building Your CI Pipeline
A CI pipeline runs automatically when code is pushed. At minimum, it should answer: "Does this code work?"
Stage 1: Install Dependencies
Start by setting up the environment. Cache dependencies to speed up subsequent runs:
- name: Cache dependencies
uses: actions/cache@v4
with:
path: vendor
key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
- name: Install dependencies
run: composer install --no-interaction --prefer-dist
Stage 2: Code Quality Checks
Run static analysis before tests. These catch issues instantly without executing code:
- name: Run Pint (code style)
run: ./vendor/bin/pint --test
- name: Run PHPStan (static analysis)
run: ./vendor/bin/phpstan analyse
Code style enforcement seems minor, but it eliminates entire categories of code review comments and keeps the codebase consistent.
Stage 3: Automated Tests
Tests are the core of CI. Run your full test suite:
- name: Run tests
run: php artisan test --parallel
env:
DB_CONNECTION: sqlite
DB_DATABASE: ":memory:"
For faster feedback, consider running tests in parallel. Most CI providers support parallelization across multiple runners.
Stage 4: Security Scanning
Automated security scanning catches known vulnerabilities in dependencies:
- name: Check for vulnerabilities
run: composer audit
For deeper analysis, integrate tools like Snyk or GitHub's Dependabot. These monitor for vulnerabilities that emerge after you've written your code.
Deployment Strategies
How you deploy affects risk and recovery time. Choose strategies based on your risk tolerance and infrastructure.
Rolling Deployments
New code is gradually rolled out across servers. At any time during deployment, some servers run old code and some run new code.
Pros: Zero downtime, easy rollback by stopping the rollout Cons: Both versions must be compatible (database migrations need care)
Blue-Green Deployments
Maintain two identical environments: blue (current) and green (new). Deploy to green, test it, then switch traffic from blue to green.
Pros: Instant rollback (switch back to blue), full testing before traffic hits new code Cons: Requires duplicate infrastructure, more complex database migration handling
Canary Releases
Route a small percentage of traffic to the new version. Monitor for errors, then gradually increase the percentage.
Pros: Real-world testing with limited blast radius, data-driven confidence Cons: Requires sophisticated traffic routing, monitoring must be excellent
Feature Flags
Deploy code to production but control feature visibility separately:
if (Feature::active('new-checkout-flow')) {
return $this->newCheckout();
}
return $this->legacyCheckout();
Pros: Deploy and release are separate decisions, instant rollback without deployment Cons: Adds complexity, flags must be cleaned up to avoid technical debt
Tool Recommendations
GitHub Actions
GitHub Actions provides CI/CD integrated with your repository. The workflow syntax is YAML-based and supports reusable workflows:
name: CI
on:
push:
branches: [main]
pull_request:
branches: [main]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: shivammathur/setup-php@v2
with:
php-version: '8.3'
- run: composer install
- run: php artisan test
GitLab CI
GitLab CI uses a similar YAML format with some different conventions:
test:
stage: test
image: php:8.3
script:
- composer install
- php artisan test
only:
- main
- merge_requests
GitLab's integrated container registry and environment management make it particularly strong for Kubernetes deployments.
Dedicated CD Tools
For complex deployments, consider dedicated tools:
- ArgoCD: GitOps for Kubernetes, syncs cluster state with Git
- Spinnaker: Multi-cloud deployment with sophisticated release strategies
- Octopus Deploy: Strong .NET support, good for hybrid environments
Common Pitfalls
Flaky Tests
Tests that sometimes pass and sometimes fail destroy CI confidence. When a test is flaky, either fix it or delete it;a flaky test is worse than no test.
Common causes:
- Race conditions in asynchronous code
- Tests depending on execution order
- Time-dependent assertions
- Shared state between tests
Slow Pipelines
A pipeline that takes 30 minutes provides feedback too late. Developers context-switch to other work and lose the thread.
Speed up pipelines by:
- Running tests in parallel
- Caching dependencies aggressively
- Running only affected tests on pull requests
- Moving slow integration tests to a separate stage
Inadequate Staging Environment
If staging doesn't match production, you'll find bugs in production. This includes:
- Same database type and version
- Similar data volumes
- Same third-party service configurations
- Equivalent infrastructure (don't test on a single server if production uses 10)
Missing Rollback Plans
Every deployment needs a rollback plan. Before deploying, know:
- How do we detect a problem?
- How do we revert the code?
- How do we revert database changes?
- Who has authority to trigger rollback?
Automate rollback where possible. If error rates spike above a threshold, automatically roll back without human intervention.
Measuring CI/CD Success
Track these metrics to understand if your CI/CD is working:
Deployment Frequency: How often do you deploy? More frequent is generally better.
Lead Time: How long from code commit to production? Shorter is better.
Mean Time to Recovery (MTTR): When something breaks, how quickly do you fix it?
Change Failure Rate: What percentage of deployments cause problems?
Elite performers deploy multiple times per day with lead times under an hour and change failure rates below 5%. Most teams have significant room to improve.
Conclusion
CI/CD isn't about tools;it's about the practice of integrating and deploying frequently with confidence. Start with automated tests and a simple deployment process. Add sophistication as you need it.
The goal isn't a perfect pipeline on day one. It's a pipeline that gets better over time, catching more issues earlier and deploying more reliably. Every team's path looks different, but the destination is the same: deployments that are so routine they're boring.