Advanced · 14 lessons
DevOps
DevOps bridges development and operations through automation, CI/CD pipelines, infrastructure as code, and monitoring. It enables teams to deploy code faster, more reliably, and with fewer errors than manual processes.
Key Concepts
Key Takeaways
- ✓ Automate everything repeatable — deployments, tests, provisioning.
- ✓ CI/CD catches bugs early and deploys code consistently.
- ✓ Infrastructure as Code (Terraform) makes servers reproducible.
- ✓ Monitor production and set alerts before users notice problems.
Lessons in This Topic
DevOps Culture & Principles
Speed, stability, and collaboration.
DevOps breaks silos between dev and ops teams. Key metrics: deployment frequency, lead time, MTTR, change failure rate. Automate manual tasks. Fail fast with automated testing. Blameless postmortems after incidents.
CI/CD with GitHub Actions
Automate testing and deployment.
Push code → GitHub Actions runs tests → builds Docker image → deploys to server. YAML workflow files define steps. Run linting, unit tests, integration tests on every PR. Auto-deploy to staging on merge to main. Manual approval gate for production.
Infrastructure as Code (Terraform)
Define servers in version-controlled files.
Terraform HCL files describe cloud resources: VMs, networks, DNS, storage. `terraform plan` previews changes; `terraform apply` creates resources. State file tracks current infrastructure. Modules reuse common patterns. Never manually click-create production resources.
Configuration Management
Ansible, Chef, and server consistency.
Ansible uses YAML playbooks to configure servers: install packages, copy configs, start services. Agentless — connects via SSH. Ensures all servers are identical. Run after Terraform provisions infrastructure. Idempotent: safe to run repeatedly.
Monitoring, Logging & Alerting
Prometheus, Grafana, and ELK stack.
Collect metrics: CPU, memory, request latency, error rates. Prometheus scrapes metrics; Grafana visualizes dashboards. ELK (Elasticsearch, Logstash, Kibana) centralizes logs. Set alerts: PagerDuty/Slack when error rate > 1% or latency > 500ms. On-call rotation for production.