Standardise credentials API (#4223) (#4163) (apache#4225)

* Standardise credentials API (#4223) (#4163)

* Clippy

* Allow HTTP metadata endpoint

Author: tustvold

src/aws/client.rs

@@ -16,8 +16,8 @@
 // under the License.
 
 use crate::aws::checksum::Checksum;
-use crate::aws::credential::{AwsCredential, CredentialExt, CredentialProvider};
-use crate::aws::{STORE, STRICT_PATH_ENCODE_SET};
+use crate::aws::credential::{AwsCredential, CredentialExt};
+use crate::aws::{AwsCredentialProvider, STORE, STRICT_PATH_ENCODE_SET};
 use crate::client::list::ListResponse;
 use crate::client::pagination::stream_paginated;
 use crate::client::retry::RetryExt;
@@ -135,7 +135,7 @@ pub struct S3Config {
     pub endpoint: String,
     pub bucket: String,
     pub bucket_endpoint: String,
-    pub credentials: Box<dyn CredentialProvider>,
+    pub credentials: AwsCredentialProvider,
     pub retry_config: RetryConfig,
     pub client_options: ClientOptions,
     pub sign_payload: bool,

src/aws/credential.rs

@@ -18,12 +18,12 @@
 use crate::aws::{STORE, STRICT_ENCODE_SET};
 use crate::client::retry::RetryExt;
 use crate::client::token::{TemporaryToken, TokenCache};
+use crate::client::TokenProvider;
 use crate::util::hmac_sha256;
 use crate::{Result, RetryConfig};
+use async_trait::async_trait;
 use bytes::Buf;
 use chrono::{DateTime, Utc};
-use futures::future::BoxFuture;
-use futures::TryFutureExt;
 use percent_encoding::utf8_percent_encode;
 use reqwest::header::{HeaderMap, HeaderValue};
 use reqwest::{Client, Method, Request, RequestBuilder, StatusCode};
@@ -41,10 +41,14 @@ static EMPTY_SHA256_HASH: &str =
     "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855";
 static UNSIGNED_PAYLOAD_LITERAL: &str = "UNSIGNED-PAYLOAD";
 
-#[derive(Debug)]
+/// A set of AWS security credentials
+#[derive(Debug, Eq, PartialEq)]
 pub struct AwsCredential {
+    /// AWS_ACCESS_KEY_ID
     pub key_id: String,
+    /// AWS_SECRET_ACCESS_KEY
     pub secret_key: String,
+    /// AWS_SESSION_TOKEN
     pub token: Option<String>,
 }
 
@@ -291,49 +295,31 @@ fn canonicalize_headers(header_map: &HeaderMap) -> (String, String) {
     (signed_headers, canonical_headers)
 }
 
-/// Provides credentials for use when signing requests
-pub trait CredentialProvider: std::fmt::Debug + Send + Sync {
-    fn get_credential(&self) -> BoxFuture<'_, Result<Arc<AwsCredential>>>;
-}
-
-/// A static set of credentials
-#[derive(Debug)]
-pub struct StaticCredentialProvider {
-    pub credential: Arc<AwsCredential>,
-}
-
-impl CredentialProvider for StaticCredentialProvider {
-    fn get_credential(&self) -> BoxFuture<'_, Result<Arc<AwsCredential>>> {
-        Box::pin(futures::future::ready(Ok(Arc::clone(&self.credential))))
-    }
-}
-
 /// Credentials sourced from the instance metadata service
 ///
 /// <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html>
 #[derive(Debug)]
 pub struct InstanceCredentialProvider {
     pub cache: TokenCache<Arc<AwsCredential>>,
-    pub client: Client,
-    pub retry_config: RetryConfig,
     pub imdsv1_fallback: bool,
     pub metadata_endpoint: String,
 }
 
-impl CredentialProvider for InstanceCredentialProvider {
-    fn get_credential(&self) -> BoxFuture<'_, Result<Arc<AwsCredential>>> {
-        Box::pin(self.cache.get_or_insert_with(|| {
-            instance_creds(
-                &self.client,
-                &self.retry_config,
-                &self.metadata_endpoint,
-                self.imdsv1_fallback,
-            )
+#[async_trait]
+impl TokenProvider for InstanceCredentialProvider {
+    type Credential = AwsCredential;
+
+    async fn fetch_token(
+        &self,
+        client: &Client,
+        retry: &RetryConfig,
+    ) -> Result<TemporaryToken<Arc<AwsCredential>>> {
+        instance_creds(client, retry, &self.metadata_endpoint, self.imdsv1_fallback)
+            .await
             .map_err(|source| crate::Error::Generic {
                 store: STORE,
                 source,
             })
-        }))
     }
 }
 
@@ -342,31 +328,34 @@ impl CredentialProvider for InstanceCredentialProvider {
 /// <https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts-technical-overview.html>
 #[derive(Debug)]
 pub struct WebIdentityProvider {
-    pub cache: TokenCache<Arc<AwsCredential>>,
     pub token_path: String,
     pub role_arn: String,
     pub session_name: String,
     pub endpoint: String,
-    pub client: Client,
-    pub retry_config: RetryConfig,
 }
 
-impl CredentialProvider for WebIdentityProvider {
-    fn get_credential(&self) -> BoxFuture<'_, Result<Arc<AwsCredential>>> {
-        Box::pin(self.cache.get_or_insert_with(|| {
-            web_identity(
-                &self.client,
-                &self.retry_config,
-                &self.token_path,
-                &self.role_arn,
-                &self.session_name,
-                &self.endpoint,
-            )
-            .map_err(|source| crate::Error::Generic {
-                store: STORE,
-                source,
-            })
-        }))
+#[async_trait]
+impl TokenProvider for WebIdentityProvider {
+    type Credential = AwsCredential;
+
+    async fn fetch_token(
+        &self,
+        client: &Client,
+        retry: &RetryConfig,
+    ) -> Result<TemporaryToken<Arc<AwsCredential>>> {
+        web_identity(
+            client,
+            retry,
+            &self.token_path,
+            &self.role_arn,
+            &self.session_name,
+            &self.endpoint,
+        )
+        .await
+        .map_err(|source| crate::Error::Generic {
+            store: STORE,
+            source,
+        })
     }
 }
 

src/aws/mod.rs

@@ -48,11 +48,13 @@ use url::Url;
 pub use crate::aws::checksum::Checksum;
 use crate::aws::client::{S3Client, S3Config};
 use crate::aws::credential::{
-    AwsCredential, CredentialProvider, InstanceCredentialProvider,
-    StaticCredentialProvider, WebIdentityProvider,
+    AwsCredential, InstanceCredentialProvider, WebIdentityProvider,
 };
 use crate::client::header::header_meta;
-use crate::client::ClientConfigKey;
+use crate::client::{
+    ClientConfigKey, CredentialProvider, StaticCredentialProvider,
+    TokenCredentialProvider,
+};
 use crate::config::ConfigValue;
 use crate::multipart::{CloudMultiPartUpload, CloudMultiPartUploadImpl, UploadPart};
 use crate::{
@@ -83,6 +85,8 @@ const STRICT_PATH_ENCODE_SET: percent_encoding::AsciiSet = STRICT_ENCODE_SET.rem
 
 const STORE: &str = "S3";
 
+type AwsCredentialProvider = Arc<dyn CredentialProvider<Credential = AwsCredential>>;
+
 /// Default metadata endpoint
 static METADATA_ENDPOINT: &str = "http://169.254.169.254";
 
@@ -1001,13 +1005,12 @@ impl AmazonS3Builder {
         let credentials = match (self.access_key_id, self.secret_access_key, self.token) {
             (Some(key_id), Some(secret_key), token) => {
                 info!("Using Static credential provider");
-                Box::new(StaticCredentialProvider {
-                    credential: Arc::new(AwsCredential {
-                        key_id,
-                        secret_key,
-                        token,
-                    }),
-                }) as _
+                let credential = AwsCredential {
+                    key_id,
+                    secret_key,
+                    token,
+                };
+                Arc::new(StaticCredentialProvider::new(credential)) as _
             }
             (None, Some(_), _) => return Err(Error::MissingAccessKeyId.into()),
             (Some(_), None, _) => return Err(Error::MissingSecretAccessKey.into()),
@@ -1031,15 +1034,18 @@ impl AmazonS3Builder {
                         .with_allow_http(false)
                         .client()?;
 
-                    Box::new(WebIdentityProvider {
-                        cache: Default::default(),
+                    let token = WebIdentityProvider {
                         token_path,
                         session_name,
                         role_arn,
                         endpoint,
+                    };
+
+                    Arc::new(TokenCredentialProvider::new(
+                        token,
                         client,
-                        retry_config: self.retry_config.clone(),
-                    }) as _
+                        self.retry_config.clone(),
+                    )) as _
                 }
                 _ => match self.profile {
                     Some(profile) => {
@@ -1049,19 +1055,20 @@ impl AmazonS3Builder {
                     None => {
                         info!("Using Instance credential provider");
 
-                        // The instance metadata endpoint is access over HTTP
-                        let client_options =
-                            self.client_options.clone().with_allow_http(true);
-
-                        Box::new(InstanceCredentialProvider {
+                        let token = InstanceCredentialProvider {
                             cache: Default::default(),
-                            client: client_options.client()?,
-                            retry_config: self.retry_config.clone(),
                             imdsv1_fallback: self.imdsv1_fallback.get()?,
                             metadata_endpoint: self
                                 .metadata_endpoint
                                 .unwrap_or_else(|| METADATA_ENDPOINT.into()),
-                        }) as _
+                        };
+
+                        Arc::new(TokenCredentialProvider::new(
+                            token,
+                            // The instance metadata endpoint is access over HTTP
+                            self.client_options.clone().with_allow_http(true).client()?,
+                            self.retry_config.clone(),
+                        )) as _
                     }
                 },
             },
@@ -1114,11 +1121,8 @@ fn profile_region(profile: String) -> Option<String> {
 }
 
 #[cfg(feature = "aws_profile")]
-fn profile_credentials(
-    profile: String,
-    region: String,
-) -> Result<Box<dyn CredentialProvider>> {
-    Ok(Box::new(profile::ProfileProvider::new(
+fn profile_credentials(profile: String, region: String) -> Result<AwsCredentialProvider> {
+    Ok(Arc::new(profile::ProfileProvider::new(
         profile,
         Some(region),
     )))
@@ -1133,7 +1137,7 @@ fn profile_region(_profile: String) -> Option<String> {
 fn profile_credentials(
     _profile: String,
     _region: String,
-) -> Result<Box<dyn CredentialProvider>> {
+) -> Result<AwsCredentialProvider> {
     Err(Error::MissingProfileFeature.into())
 }
 

src/aws/profile.rs

@@ -17,21 +17,21 @@
 
 #![cfg(feature = "aws_profile")]
 
+use async_trait::async_trait;
 use aws_config::meta::region::ProvideRegion;
 use aws_config::profile::profile_file::ProfileFiles;
 use aws_config::profile::ProfileFileCredentialsProvider;
 use aws_config::profile::ProfileFileRegionProvider;
 use aws_config::provider_config::ProviderConfig;
 use aws_credential_types::provider::ProvideCredentials;
 use aws_types::region::Region;
-use futures::future::BoxFuture;
 use std::sync::Arc;
 use std::time::Instant;
 use std::time::SystemTime;
 
-use crate::aws::credential::CredentialProvider;
 use crate::aws::AwsCredential;
 use crate::client::token::{TemporaryToken, TokenCache};
+use crate::client::CredentialProvider;
 use crate::Result;
 
 #[cfg(test)]
@@ -91,38 +91,43 @@ impl ProfileProvider {
     }
 }
 
+#[async_trait]
 impl CredentialProvider for ProfileProvider {
-    fn get_credential(&self) -> BoxFuture<'_, Result<Arc<AwsCredential>>> {
-        Box::pin(self.cache.get_or_insert_with(move || async move {
-            let region = self.region.clone().map(Region::new);
-
-            let config = ProviderConfig::default().with_region(region);
-
-            let credentials = ProfileFileCredentialsProvider::builder()
-                .configure(&config)
-                .profile_name(&self.name)
-                .build();
-
-            let c = credentials.provide_credentials().await.map_err(|source| {
-                crate::Error::Generic {
-                    store: "S3",
-                    source: Box::new(source),
-                }
-            })?;
-            let t_now = SystemTime::now();
-            let expiry = c
-                .expiry()
-                .and_then(|e| e.duration_since(t_now).ok())
-                .map(|ttl| Instant::now() + ttl);
-
-            Ok(TemporaryToken {
-                token: Arc::new(AwsCredential {
-                    key_id: c.access_key_id().to_string(),
-                    secret_key: c.secret_access_key().to_string(),
-                    token: c.session_token().map(ToString::to_string),
-                }),
-                expiry,
+    type Credential = AwsCredential;
+
+    async fn get_credential(&self) -> Result<Arc<AwsCredential>> {
+        self.cache
+            .get_or_insert_with(move || async move {
+                let region = self.region.clone().map(Region::new);
+
+                let config = ProviderConfig::default().with_region(region);
+
+                let credentials = ProfileFileCredentialsProvider::builder()
+                    .configure(&config)
+                    .profile_name(&self.name)
+                    .build();
+
+                let c = credentials.provide_credentials().await.map_err(|source| {
+                    crate::Error::Generic {
+                        store: "S3",
+                        source: Box::new(source),
+                    }
+                })?;
+                let t_now = SystemTime::now();
+                let expiry = c
+                    .expiry()
+                    .and_then(|e| e.duration_since(t_now).ok())
+                    .map(|ttl| Instant::now() + ttl);
+
+                Ok(TemporaryToken {
+                    token: Arc::new(AwsCredential {
+                        key_id: c.access_key_id().to_string(),
+                        secret_key: c.secret_access_key().to_string(),
+                        token: c.session_token().map(ToString::to_string),
+                    }),
+                    expiry,
+                })
             })
-        }))
+            .await
     }
 }