Implement a custom retryable strategy for sourcify reqwest middleware (…

…#617)

* Implement a custom retryable strategy for sourcify reqwest middleware

* Turn on the verify_from_etherscan_contract_not_verified' test case. Return sourcify lib version to v1.0.0.

* Refactor test error messages

libs/sourcify/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sourcify"
-version = "0.1.1"
+version = "0.1.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
@@ -11,7 +11,7 @@ bytes = "1.4.0"
 blockscout-display-bytes = "1.0.0"
 reqwest = { version = "0.11.18", features = ["json"] }
 reqwest-middleware = "0.2.2"
-reqwest-retry = "0.2.2"
+reqwest-retry = "0.3.0"
 serde = { version = "1.0.164", features = ["derive"] }
 serde_json = "1.0.96"
 thiserror = "1.0.40"

libs/sourcify/src/client.rs

@@ -14,6 +14,40 @@ use serde::{Deserialize, Serialize};
 use std::{str::FromStr, sync::Arc};
 use url::Url;
 
+mod retryable_strategy {
+ use reqwest::StatusCode;
+ use reqwest_middleware::Error;
+ use reqwest_retry::{Retryable, RetryableStrategy};
+
+ pub struct SourcifyRetryableStrategy;
+
+ impl RetryableStrategy for SourcifyRetryableStrategy {
+ fn handle(&self, res: &Result<reqwest::Response, Error>) -> Option<Retryable> {
+ match res {
+ Ok(success) => default_on_request_success(success),
+ Err(error) => reqwest_retry::default_on_request_failure(error),
+ }
+ }
+ }
+
+ // The strategy differs from `reqwest_retry::default_on_request_success`
+ // by considering 500 errors as Fatal instead of Transient.
+ // The reason is that Sourcify uses 500 code to propagate fatal internal errors,
+ // which will not be resolved on retry and which we would like to get early to process.
+ fn default_on_request_success(success: &reqwest::Response) -> Option<Retryable> {
+ let status = success.status();
+ if status.is_server_error() && status != StatusCode::INTERNAL_SERVER_ERROR {
+ Some(Retryable::Transient)
+ } else if status.is_success() {
+ None
+ } else if status == StatusCode::REQUEST_TIMEOUT || status == StatusCode::TOO_MANY_REQUESTS {
+ Some(Retryable::Transient)
+ } else {
+ Some(Retryable::Fatal)
+ }
+ }
+}
+
 #[derive(Clone)]
 pub struct ClientBuilder {
  base_url: Url,
@@ -56,7 +90,10 @@ impl ClientBuilder {
  pub fn build(self) -> Client {
  let retry_policy = ExponentialBackoff::builder().build_with_max_retries(self.max_retries);
  let mut client_builder = reqwest_middleware::ClientBuilder::new(reqwest::Client::new())
- .with(RetryTransientMiddleware::new_with_policy(retry_policy));
+ .with(RetryTransientMiddleware::new_with_policy_and_strategy(
+ retry_policy,
+ retryable_strategy::SourcifyRetryableStrategy,
+ ));
  for middleware in self.middleware_stack {
  client_builder = client_builder.with_arc(middleware);
  }
@@ -246,7 +283,7 @@ mod tests {
  fn client() -> Client {
  let rate_limiter = rate_limiter_middleware().clone();
  ClientBuilder::default()
- .max_retries(1)
+ .max_retries(3)
  .with_arc_middleware(rate_limiter)
  .build()
  }
@@ -393,7 +430,7 @@ mod tests {
  .expect_err("error expected");
  assert!(
  matches!(result, Error::Sourcify(SourcifyError::ChainNotSupported(_))),
- "expected: 'SourcifyError::BadRequest', got: {result:?}"
+ "expected: 'SourcifyError::ChainNotSupported', got: {result:?}"
  );
  }
 
@@ -417,32 +454,37 @@ mod tests {
  .verify_from_etherscan(chain_id, contract_address)
  .await
  .expect_err("error expected");
- assert!(matches!(
- result,
- Error::Sourcify(SourcifyError::Custom(
- VerifyFromEtherscanError::ChainNotSupported(_)
- ))
- ));
+ assert!(
+ matches!(
+ result,
+ Error::Sourcify(SourcifyError::Custom(
+ VerifyFromEtherscanError::ChainNotSupported(_)
+ ))
+ ),
+ "expected: 'SourcifyError::ChainNotSupported', got: {result:?}"
+ );
  }
 
- // TODO: returns TooManyRequests to the Etherscan API for some reason
- // #[tokio::test]
- // async fn verify_from_etherscan_contract_not_verified() {
- // let chain_id = "5";
- // let contract_address =
- // parse_contract_address("0x847F2d0c193E90963aAD7B2791aAE8d7310dFF6A");
- //
- // let result = client()
- // .verify_from_etherscan(chain_id, contract_address)
- // .await
- // .expect_err("error expected");
- // assert!(matches!(
- // result,
- // Error::Sourcify(SourcifyError::Custom(
- // VerifyFromEtherscanError::ContractNotVerified(_)
- // ))
- // ));
- // }
+ #[tokio::test]
+ async fn verify_from_etherscan_contract_not_verified() {
+ let chain_id = "5";
+ let contract_address =
+ parse_contract_address("0x847F2d0c193E90963aAD7B2791aAE8d7310dFF6A");
+
+ let result = client()
+ .verify_from_etherscan(chain_id, contract_address)
+ .await
+ .expect_err("error expected");
+ assert!(
+ matches!(
+ result,
+ Error::Sourcify(SourcifyError::Custom(
+ VerifyFromEtherscanError::ContractNotVerified(_)
+ ))
+ ),
+ "expected: 'SourcifyError::ContractNotVerified', got: {result:?}"
+ );
+ }
 
  /*
  * Not implemented to avoid unnecessary burden on the Sourcify server.