DevOps Fundamentals
DevOps Fundamentals tests the practices that shorten the path from commit to production while keeping it reliable: version control, continuous integration and delivery, infrastructure as code, containers, and observability.
Flow and feedback
Version control is the source of truth; every change should be reviewable and traceable. Continuous integration merges changes frequently and runs automated build and test steps. Continuous delivery keeps every validated change releasable; continuous deployment goes further and releases automatically. Infrastructure as code defines servers, networks, and policies in files so environments are reproducible and reviewed like software.
Containers and orchestration
A container packages an application with its dependencies and shares the host kernel; a virtual machine includes a full guest OS. Immutable images are built once, tagged, and promoted between environments rather than rebuilt per environment. Orchestrators such as Kubernetes schedule containers, restart failed ones, and expose services.
Observability
Metrics, logs, and traces answer different questions: metrics show trends and alerts, logs show discrete events, traces show a request across services. Instrument before incidents, not during them.
Worked example: a pipeline builds an image, runs unit tests, scans it, and pushes it to a registry; deployment promotes the same image digest to staging and production. Rebuilding the image for production would break the guarantee that what was tested is what ships, so promotion by immutable digest is correct.
Traps: treating CI as continuous deployment; storing secrets in the repository; configuring production by hand after an IaC run, which creates drift; and assuming containers are a security boundary equivalent to VMs. A failed test should stop the pipeline, not be overridden routinely.