Disable S3 dependencies when s3 feature is disabled

Cargo.toml

@@ -15,10 +15,8 @@ license = "MIT"
 readme = "README.md"
 
 [features]
-default = ["dimse", "s3"]
-dimse = []
-# TODO: feature-gate S3 dependencies
-s3 = []
+default = []
+s3 = ["dep:aws-config", "dep:aws-sdk-s3", "dep:aws-credential-types"]
 
 [dependencies]
 # DICOM processing
@@ -54,9 +52,9 @@ multer = "3.1.0"
 pin-project = "1.1.10"
 image = { version = "0.25.6", features = ["png", "jpeg", "gif"] }
 # S3 backend
-aws-config = { version = "1.6.2", features = ["behavior-version-latest"] }
-aws-sdk-s3 = "1.85.0"
-aws-credential-types = "1.2.3"
+aws-config = { version = "1.6.2", features = ["behavior-version-latest"], optional = true }
+aws-sdk-s3 = { version = "1.85.0", optional = true }
+aws-credential-types = { version = "1.2.3", optional = true }
 
 [lints.rust]
 unsafe_code = "forbid"

src/backend/mod.rs

@@ -1,20 +1,14 @@
 use crate::api::qido::QidoService;
 use crate::api::stow::StowService;
 use crate::api::wado::WadoService;
-use crate::backend::dimse::qido::DimseQidoService;
-use crate::backend::dimse::stow::DimseStowService;
-use crate::backend::dimse::wado::DimseWadoService;
-use crate::backend::s3::wado::S3WadoService;
 use crate::config::BackendConfig;
 use crate::AppState;
-use async_trait::async_trait;
 use axum::extract::{FromRef, FromRequestParts, Path};
 use axum::http::request::Parts;
 use axum::http::StatusCode;
 use serde::Deserialize;
 use std::time::Duration;
 
-// #[cfg(feature = "dimse")]
 pub mod dimse;
 
 #[cfg(feature = "s3")]
@@ -54,8 +48,11 @@ where
 
 		// TODO: Use a singleton to avoid re-creating on every request.
 		let provider = match ae_config.backend {
-			#[cfg(feature = "dimse")]
 			BackendConfig::Dimse { .. } => {
+				use crate::backend::dimse::qido::DimseQidoService;
+				use crate::backend::dimse::stow::DimseStowService;
+				use crate::backend::dimse::wado::DimseWadoService;
+
 				let pool = state.pools.get(&ae_config.aet).expect("pool should exist");
 
 				Self {
@@ -75,19 +72,16 @@ where
 					))),
 				}
 			}
-			// For some reason serde doesn't work with feature-gated enum variants.
-			// A no-op backend is used as a workaround if the dimse feature is not enabled.
-			#[cfg(not(feature = "dimse"))]
-			Backend::Dimse => Self {
-				qido: None,
-				wado: None,
-				stow: None,
-			},
-			BackendConfig::S3(config) => Self {
-				qido: None,
-				wado: Some(Box::new(S3WadoService::new(&config))),
-				stow: None,
-			},
+			#[cfg(feature = "s3")]
+			BackendConfig::S3(config) => {
+				use crate::backend::s3::wado::S3WadoService;
+
+				Self {
+					qido: None,
+					wado: Some(Box::new(S3WadoService::new(&config))),
+					stow: None,
+				}
+			}
 		};
 
 		Ok(provider)

src/config/mod.rs

@@ -1,6 +1,6 @@
 use crate::types::AE;
 use crate::DEFAULT_AET;
-use aws_credential_types::Credentials as AwsCredentials;
+
 use serde::de::Error;
 use serde::{Deserialize, Deserializer};
 use std::net::IpAddr;
@@ -36,6 +36,7 @@ pub struct ApplicationEntityConfig {
 pub enum BackendConfig {
 	#[serde(rename = "DIMSE")]
 	Dimse(DimseConfig),
+	#[cfg(feature = "s3")]
 	#[serde(rename = "S3")]
 	S3(S3Config),
 }
@@ -49,6 +50,7 @@ pub struct DimseConfig {
 	pub pool: PoolConfig,
 }
 
+#[cfg(feature = "s3")]
 #[derive(Debug, Clone, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct S3Config {
@@ -63,19 +65,22 @@ pub struct S3Config {
 	pub endpoint_style: S3EndpointStyle,
 }
 
+#[cfg(feature = "s3")]
 #[derive(Debug, Clone, Deserialize)]
 #[serde(rename_all = "lowercase")]
 pub enum S3EndpointStyle {
 	Path,
 	VHost,
 }
 
+#[cfg(feature = "s3")]
 impl Default for S3EndpointStyle {
 	fn default() -> Self {
 		Self::VHost
 	}
 }
 
+#[cfg(feature = "s3")]
 #[derive(Debug, Clone, Deserialize)]
 #[serde(untagged)]
 pub enum S3CredentialsConfig {
@@ -91,13 +96,14 @@ pub enum S3CredentialsConfig {
 	},
 }
 
+#[cfg(feature = "s3")]
 impl S3CredentialsConfig {
-	pub fn resolve(&self) -> Result<AwsCredentials, std::env::VarError> {
+	pub fn resolve(&self) -> Result<aws_credential_types::Credentials, std::env::VarError> {
 		match &self {
 			Self::Plain {
 				access_key,
 				secret_key,
-			} => Ok(AwsCredentials::new(
+			} => Ok(aws_credential_types::Credentials::new(
 				access_key,
 				secret_key,
 				None,
@@ -110,7 +116,7 @@ impl S3CredentialsConfig {
 			} => {
 				let access_key = std::env::var(access_key_env)?;
 				let secret_key = std::env::var(secret_key_env)?;
-				Ok(AwsCredentials::new(
+				Ok(aws_credential_types::Credentials::new(
 					access_key,
 					secret_key,
 					None,
@@ -274,14 +280,9 @@ pub enum Backend {
 }
 
 impl Default for Backend {
-	#[cfg(feature = "dimse")]
 	fn default() -> Self {
 		Self::Dimse
 	}
-	#[cfg(not(feature = "dimse"))]
-	fn default() -> Self {
-		Self::Disabled
-	}
 }
 
 impl Default for DimseServerConfig {

src/main.rs

@@ -57,9 +57,7 @@ fn init_logger(level: tracing::Level) {
 #[derive(Clone)]
 pub struct AppState {
 	pub config: AppConfig,
-	#[cfg(feature = "dimse")]
 	pub pools: AssociationPools,
-	#[cfg(feature = "dimse")]
 	pub mediator: MoveMediator,
 }
 
@@ -102,20 +100,15 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 }
 
 async fn run(config: AppConfig) -> anyhow::Result<()> {
-	#[cfg(feature = "dimse")]
 	let mediator = MoveMediator::new(&config);
-	#[cfg(feature = "dimse")]
 	let pools = AssociationPools::new(&config);
 
 	let app_state = AppState {
 		config: config.clone(),
-		#[cfg(feature = "dimse")]
 		mediator: mediator.clone(),
-		#[cfg(feature = "dimse")]
 		pools,
 	};
 
-	#[cfg(feature = "dimse")]
 	for dimse_config in config.server.dimse {
 		let mediator = mediator.clone();
 		let subscribers: Vec<AE> = config