Make async provide credentials async-trait compatible (#588) (346cdfe9) · Commits · Public Repositories / Smithy Rust

aws/rust-runtime/aws-auth/Cargo.toml

+1 −0

Original line number	Diff line number	Diff line
		@@ -14,3 +14,4 @@ zeroize = "1.2.0"
		[dev-dependencies]
		http = "0.2.3"
		tokio = { version = "1.0", features = ["rt", "macros"] }
		async-trait = "0.1.50"

aws/rust-runtime/aws-auth/src/middleware.rs

+5 −2

Original line number	Diff line number	Diff line
		@@ -72,13 +72,16 @@ impl AsyncMapRequest for CredentialsStage {

		fn apply(&self, mut request: Request) -> BoxFuture<Result<Request, Self::Error>> {
		Box::pin(async move {
		let cred_future = {
		let provider = {
		let config = request.config();
		let credential_provider = config
		.get::<CredentialsProvider>()
		.ok_or(CredentialsStageError::MissingCredentialsProvider)?;
		credential_provider.provide_credentials()
		// we need to enable releasing the config lock so that we don't hold the config
		// lock across an await point
		credential_provider.clone()
		};
		let cred_future = { provider.provide_credentials() };
		let credentials = cred_future.await?;
		request.config_mut().insert(credentials);
		Ok(request)

aws/rust-runtime/aws-auth/src/provider.rs

+38 −5

Original line number	Diff line number	Diff line
		@@ -40,7 +40,7 @@ impl Error for CredentialsError {
		}

		pub type CredentialsResult = Result<Credentials, CredentialsError>;
		type BoxFuture<T> = Pin<Box<dyn Future<Output = T> + Send>>;
		type BoxFuture<'a, T> = Pin<Box<dyn Future<Output = T> + Send + 'a>>;

		/// An asynchronous credentials provider
		///
		@@ -48,7 +48,9 @@ type BoxFuture<T> = Pin<Box<dyn Future<Output = T> + Send>>;
		/// consider using [`async_provide_credentials_fn`] with a closure rather than directly implementing
		/// this trait.
		pub trait AsyncProvideCredentials: Send + Sync {
		fn provide_credentials(&self) -> BoxFuture<CredentialsResult>;
		fn provide_credentials<'a>(&'a self) -> BoxFuture<'a, CredentialsResult>
		where
		Self: 'a;
		}

		pub type CredentialsProvider = Arc<dyn AsyncProvideCredentials>;
		@@ -66,7 +68,10 @@ where
		T: Fn() -> F + Send + Sync,
		F: Future<Output = CredentialsResult> + Send + 'static,
		{
		fn provide_credentials(&self) -> BoxFuture<CredentialsResult> {
		fn provide_credentials<'a>(&'a self) -> BoxFuture<'a, CredentialsResult>
		where
		Self: 'a,
		{
		Box::pin((self.f)())
		}
		}
		@@ -81,9 +86,13 @@ where
		/// use aws_auth::Credentials;
		/// use aws_auth::provider::async_provide_credentials_fn;
		///
		/// async fn load_credentials() -> Credentials {
		/// todo!()
		/// }
		///
		/// async_provide_credentials_fn(\|\| async {
		/// // Async process to retrieve credentials goes here
		/// let credentials: Credentials = todo!().await?;
		/// let credentials = load_credentials().await;
		/// Ok(credentials)
		/// });
		/// ```
		@@ -107,7 +116,10 @@ impl<T> AsyncProvideCredentials for T
		where
		T: ProvideCredentials,
		{
		fn provide_credentials(&self) -> BoxFuture<CredentialsResult> {
		fn provide_credentials<'a>(&'a self) -> BoxFuture<'a, CredentialsResult>
		where
		Self: 'a,
		{
		let result = self.provide_credentials();
		Box::pin(future::ready(result))
		}
		@@ -130,7 +142,9 @@ pub fn set_provider(config: &mut PropertyBag, provider: Arc<dyn AsyncProvideCred

		#[cfg(test)]
		mod test {
		use crate::provider::{AsyncProvideCredentials, BoxFuture, CredentialsResult};
		use crate::Credentials;
		use async_trait::async_trait;

		fn assert_send_sync<T: Send + Sync>() {}

		@@ -138,4 +152,23 @@ mod test {
		fn creds_are_send_sync() {
		assert_send_sync::<Credentials>()
		}

		#[async_trait]
		trait AnotherTrait: Send + Sync {
		async fn creds(&self) -> Credentials;
		}

		struct AnotherTraitWrapper<T> {
		inner: T,
		}

		impl<T: AnotherTrait> AsyncProvideCredentials for AnotherTraitWrapper<T> {
		fn provide_credentials<'a>(&'a self) -> BoxFuture<'a, CredentialsResult>
		where
		Self: 'a,
		{
		let inner_fut = self.inner.creds();
		Box::pin(async move { Ok(inner_fut.await) })
		}
		}
		}