When API deployment settings are changed outside version control, teams can lose track of what changed and allow configurations to drift. Configuration as code (CaC) manages application configuration through descriptive, version-controlled files. Teams can template, roll out, and track changes rather than rely on manual updates. section 1.2 section 1.5.5
CaC applies the version-controlled approach of infrastructure as code to deployed applications rather than infrastructure resources. For API gateways, a declarative configuration states the desired result; an agent sets up the system to match it. An imperative script instead specifies the commands and their order. Keeping the declarative files in Git lets a team collaborate through Git workflows. section 1.2 section 1.5.5
The file to version depends on the API gateway:
- Amazon API Gateway and Kusk API Gateway can place declarative settings in OpenAPI vendor extensions. section 1.5.5
- Apigee Edge uses separate declarative configuration files. section 1.5.5
- Kong and Tyk ingress controllers can use Kubernetes Custom Resource Definitions in manifest files. section 1.5.5
The format is gateway-specific, but the operational rule is the same: store the declarative configuration in version control so deployment settings can participate in an APIOps workflow. section 1.5.5
