WIP: concurrent integration tests

[justinmoon]

This PR generates random ports for server and gateway to bind to. I pulled in a portpicker dependency. That project is just 75 LOC with public domain license, so I think we could just copy any relevant code into our project if this works.

[justinmoon]

CI gets stuck on the runs_consensus_if_tx_submitted tests ... will investigate more later

[justinmoon]

Eric mentioned alternative fix for making the gateway work in concurrent tests: don't bind to a port. "Interconnect" is able to fake the network layer for our client / server communications in tests. We could do something similar for the gateway.

[elsirion]

We could probably re-use the great API @maan2003 built

fedimint/fedimint-api/src/module/mod.rs

Lines 42 to 126 in 2cd4cb8

	#[async_trait]
	pub trait TypedApiEndpoint {
	type State: Sync;
	/// example: /transaction
	const PATH: &'static str;
	type Param: serde::de::DeserializeOwned + Send;
	type Response: serde::Serialize;
	async fn handle(state: &Self::State, params: Self::Param) -> Result<Self::Response, ApiError>;
	}
	#[doc(hidden)]
	pub mod __reexports {
	pub use serde_json;
	}
	/// # Example
	///
	/// ```rust
	/// # use fedimint_api::module::{api_endpoint, ApiEndpoint};
	/// struct State;
	///
	/// let _: ApiEndpoint<State> = api_endpoint! {
	/// "/foobar",
	/// async |state: &State, params: ()| -> i32 {
	/// Ok(0)
	/// }
	/// };
	/// ```
	#[macro_export]
	macro_rules! __api_endpoint {
	(
	$path:expr,
	async |$state:ident: &$state_ty:ty, $param:ident: $param_ty:ty| -> $resp_ty:ty $body:block
	) => {{
	struct Endpoint;
	#[async_trait::async_trait]
	impl $crate::module::TypedApiEndpoint for Endpoint {
	const PATH: &'static str = $path;
	type State = $state_ty;
	type Param = $param_ty;
	type Response = $resp_ty;
	async fn handle(
	$state: &Self::State,
	$param: Self::Param,
	) -> ::std::result::Result<Self::Response, $crate::module::ApiError> {
	$body
	}
	}
	ApiEndpoint {
	path: <Endpoint as $crate::module::TypedApiEndpoint>::PATH,
	handler: |m, param| {
	Box::pin(async move {
	let params = $crate::module::__reexports::serde_json::from_value(param)
	.map_err(|e| $crate::module::ApiError::bad_request(e.to_string()))?;
	let ret =
	<Endpoint as $crate::module::TypedApiEndpoint>::handle(m, params).await?;
	Ok($crate::module::__reexports::serde_json::to_value(ret)
	.expect("encoding error"))
	})
	},
	}
	}};
	}
	pub use __api_endpoint as api_endpoint;
	/// Definition of an API endpoint defined by a module `M`.
	pub struct ApiEndpoint<M> {
	/// Path under which the API endpoint can be reached. It should start with a `/`
	/// e.g. `/transaction`. E.g. this API endpoint would be reachable under `/module_name/transaction`
	/// depending on the module name returned by `[FedertionModule::api_base_name]`.
	pub path: &'static str,
	/// Handler for the API call that takes the following arguments:
	/// * Reference to the module which defined it
	/// * Request parameters parsed into JSON `[Value](serde_json::Value)`
	pub handler:
	for<'a> fn(&'a M, serde_json::Value) -> BoxFuture<'a, Result<serde_json::Value, ApiError>>,
	}

[justinmoon]

Closing this. #497 is a better approach.

[NicolaLS]

@justinmoon we might still want to switch to portpicker later because we have no guarantee that 4000+((testi_peers*2 + 1)*i) are not used by some other process on the machine

[justinmoon]

@NicolaLS Could you try to PR this again? @elsirion was mentioning that he's still getting port-conflicts locally ...

[elsirion]

I think I fixed it here: a4f918a#diff-48b39828fd7e697f30f09e9a1830b0b515e704bc621c47fdeaa597796a0d0abdR180