September 21st, 2022

Breaking Changes:

• ⚠ (smithy-rs#1603, aws-sdk-rust#586) aws_config::RetryConfig no longer implements Default, and its new function has been replaced with standard.
• ⚠ (smithy-rs#1603, aws-sdk-rust#586) Direct configuration of aws_config::SdkConfig now defaults to retries being disabled.
  If you're using aws_config::load_from_env() or aws_config::from_env() to configure
  the SDK, then you are NOT affected by this change. If you use SdkConfig::builder() to
  configure the SDK, then you ARE affected by this change and should set the retry config
  on that builder.
• ⚠ (smithy-rs#1603, aws-sdk-rust#586) Client creation now panics if retries or timeouts are enabled without an async sleep
  implementation set on the SDK config.
  If you're using the Tokio runtime and have the rt-tokio feature enabled (which is enabled by default),
  then you shouldn't notice this change at all.
  Otherwise, if using something other than Tokio as the async runtime, the AsyncSleep trait must be implemented,
  and that implementation given to the config builder via the sleep_impl method. Alternatively, retry can be
  explicitly turned off by setting the retry config to RetryConfig::disabled(), which will result in successful
  client creation without an async sleep implementation.
• ⚠ (smithy-rs#1715, smithy-rs#1717) ClassifyResponse was renamed to ClassifyRetry and is no longer implemented for the unit type.
• ⚠ (smithy-rs#1715, smithy-rs#1717) The with_retry_policy and retry_policy functions on aws_smithy_http::operation::Operation have been
  renamed to with_retry_classifier and retry_classifier respectively. Public member retry_policy on
  aws_smithy_http::operation::Parts has been renamed to retry_classifier.

New this release:

• 🎉 (smithy-rs#1647, smithy-rs#1112) Implemented customizable operations per RFC-0017.

  Before this change, modifying operations before sending them required using lower-level APIs:

  let input = SomeOperationInput::builder().some_value(5).build()?;
  
  let operation = {
      let op = input.make_operation(&service_config).await?;
      let (request, response) = op.into_request_response();
  
      let request = request.augment(|req, _props| {
          req.headers_mut().insert(
              HeaderName::from_static("x-some-header"),
              HeaderValue::from_static("some-value")
          );
          Result::<_, Infallible>::Ok(req)
      })?;
  
      Operation::from_parts(request, response)
  };
  
  let response = smithy_client.call(operation).await?;

  Now, users may easily modify operations before sending with the customize method:

  let response = client.some_operation()
      .some_value(5)
      .customize()
      .await?
      .mutate_request(|mut req| {
          req.headers_mut().insert(
              HeaderName::from_static("x-some-header"),
              HeaderValue::from_static("some-value")
          );
      })
      .send()
      .await?;

• 🐛 (smithy-rs#966, smithy-rs#1718) The AWS STS SDK now automatically retries IDPCommunicationError when calling AssumeRoleWithWebIdentity

• 🐛 (aws-sdk-rust#303, smithy-rs#1717) The SdkError::ResponseError, typically caused by a connection terminating before the full response is received, is now treated as a transient failure and retried.