Custom service configuration

A custom configuration relates to your business logic and your requirements. It is not used by PURISTA itself. The custom service config will be available in all commands and subscriptions of this service via this.config. Custom service configurations are one option to pass configuration values to commands and subscriptions. But, you can also use stores.

Service configuration and stores addressing different data. Here is a table, that will help you to understand the differences.

	custom config	Config Store	Secret store
provided/managed by	infrastructure & deployment	database or vendor solution	vendor solution
addresses	technical configuration	business configuration	secrets & confidential data
value	is set once, during instance creation	fetched per usage	fetched per usage
change effects	instance restart/next deployment	on next usage	on next usage
value type	object (nested)	object, string, number, boolean (key-value)	string (key-value)
can be set ()*	🛑 no	✅ yes	✅ yes
can be deleted ()*	🛑 no	✅ yes	✅ yes
use for confidential data	🙏🏻 please no, technically possible	🙏🏻 please no, technically possible	✅ yes
use cases	third-party url, ports, timeout settings	feature flag, business data like currency exchange values	passwords, auth tokens, certificates

(*) by commands and subscriptions

For a custom configuration, you must define a zod schema. Example:

export const userServiceV1ConfigSchema = z.object({
  myOption: z.string().optional().default('something')
})

export type UserServiceV1Config = z.input<typeof userServiceV1ConfigSchema>

export const userV1ServiceBuilder = new ServiceBuilder(userServiceInfo)
  .setConfigSchema(userServiceV1ConfigSchema)

As you can see, in the example an optional string entry myOption is added. This field is marked as optional. Because of this, in the generated type UserServiceV1Config, the myOption is also optional.

The schema also contains a default value for myOption. If no value is provided during configuration, the default value will be used.