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Traditionally, Kong Gateway has always required a database, either PostgreSQL or Cassandra, to store entities such as Routes, Services, and Plugins during runtime. The database settings are typically stored in a configuration file called
Kong Gateway 1.1 added the ability to run the Gateway without a database. This ability is called DB-less mode. Since not having a database would preclude using the Admin API to create entities, the entities must be declared in another configuration file (YAML or JSON). This file is known as the declarative configuration, or declarative config for short.
DB-less mode and declarative configuration bring a number of benefits over using a database:
- Reduced lookup latency: all data is local to the cluster’s node.
- Reduced dependencies: only the Kong Gateway nodes and configuration are required.
- Single source of truth: entities are stored in a single file which can be source-controlled.
- New deployment models: Kong Gateway can now easily serve as a lightweight node.
Now that you’re familiar with the value that DB-less mode and declarative configuration can provide, let’s walk through how Kong Studio’s Insomnia Designer can help you go from an OpenAPI spec to Kong Declarative Configuration.
Step 1: Create or import a spec into Insomnia Designer
Copy the spec you’d like to convert to declarative config to your clipboard. If you don’t have a spec on hand, you can test it out using the Petstore specification.
Navigate to the Documents Listing View and click Create, then select Blank Document from the dropdown.
- Name the document and click Create.
- Inside the Editor field, paste the specification you copied in Step 1. You should now see the specification in the Editor.
Step 2: Generate a config
Now that you’ve added a specification to Insomnia Designer, you can generate a Kong Declarative Configuration.
In the upper right-hand corner of the editor, click Generate Config.
A modal window appears displaying the generated configuration as YAML. At the bottom of the modal, click the button to Copy to Clipboard.