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AWS Options

Options allow you to configure clients in code. Configuration via options takes precedence over all other configuration sources.

Basic usage​

Each client has an accompanying options interface and class e.g. ISQSOptions and TSQSOptions for use with the TSQSClient class.

var
  Options: ISQSOptions;
begin
  Options := TSQSOptions.Create;
  Options.RetryLimit := 5;
  SQS := TSQSClient.Create(Options);
end.

Common options​

Every options interface extends IAWSOptions which defines the options common to all clients, such as credentials, region, retry behaviour, and endpoints.

Service-scoped options​

Options created with a service-specific class like TS3Options are scoped to that service. This allows you to build a single options object where most clients use common defaults but specific services are configured differently.

For example, to point S3 at a third-party provider while all other services use the default AWS endpoints:

var
  S3Opts: IS3Options;
  Options: IAWSOptions;
begin
  S3Opts := TS3Options.Create;
  S3Opts.EndpointUrl := 'https://s3.example.com';

  Options := TAWSOptions.Create(S3Opts);

  // S3 clients will use s3.example.com
  S3 := TS3Client.Create(Options);

  // Other clients will use the default AWS endpoints
  SQS := TSQSClient.Create(Options);
end.

All options classes accept an IAWSOptions in their constructor. The merge logic handles scoping automatically so service-specific values only apply to their respective clients.

Note that all clients accept IAWSOptions, not just their own options type. If you pass an ISNSOptions to an S3 client, the SNS-scoped values will be ignored and only common values from IAWSOptions will apply. To configure a specific client, use the matching options class for that service, or a TAWSOptions which will apply to any client.