web3-proxy/src/main.rs
2022-04-29 19:22:59 +00:00

391 lines
15 KiB
Rust

mod block_watcher;
mod provider;
mod provider_tiers;
use futures::future;
use governor::clock::{Clock, QuantaClock};
use serde_json::json;
use std::collections::HashMap;
use std::fmt;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::{mpsc, watch, RwLock};
use tokio::time::sleep;
use tracing::warn;
use warp::Filter;
// use crate::types::{BlockMap, ConnectionsMap, RpcRateLimiterMap};
use crate::block_watcher::BlockWatcher;
use crate::provider::JsonRpcRequest;
use crate::provider_tiers::Web3ProviderTier;
static APP_USER_AGENT: &str = concat!(
"satoshiandkin/",
env!("CARGO_PKG_NAME"),
"/",
env!("CARGO_PKG_VERSION"),
);
/// The application
// TODO: this debug impl is way too verbose. make something smaller
struct Web3ProxyApp {
/// clock used for rate limiting
/// TODO: use tokio's clock (will require a different ratelimiting crate)
clock: QuantaClock,
/// Send requests to the best server available
balanced_rpc_tiers: Arc<Vec<Web3ProviderTier>>,
/// Send private requests (like eth_sendRawTransaction) to all these servers
private_rpcs: Option<Arc<Web3ProviderTier>>,
/// write lock on these when all rate limits are hit
/// this lock will be held open over an await, so use async locking
balanced_rpc_ratelimiter_lock: RwLock<()>,
/// this lock will be held open over an await, so use async locking
private_rpcs_ratelimiter_lock: RwLock<()>,
}
impl fmt::Debug for Web3ProxyApp {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("Web3ProxyApp").finish_non_exhaustive()
}
}
impl Web3ProxyApp {
async fn try_new(
allowed_lag: u64,
balanced_rpc_tiers: Vec<Vec<(&str, u32)>>,
private_rpcs: Vec<(&str, u32)>,
) -> anyhow::Result<Web3ProxyApp> {
let clock = QuantaClock::default();
let mut rpcs = vec![];
for balanced_rpc_tier in balanced_rpc_tiers.iter() {
for rpc_data in balanced_rpc_tier {
let rpc = rpc_data.0.to_string();
rpcs.push(rpc);
}
}
for rpc_data in private_rpcs.iter() {
let rpc = rpc_data.0.to_string();
rpcs.push(rpc);
}
let block_watcher = Arc::new(BlockWatcher::new(rpcs));
// make a http shared client
// TODO: how should we configure the connection pool?
// TODO: 5 minutes is probably long enough. unlimited is a bad idea if something is wrong with the remote server
let http_client = reqwest::ClientBuilder::new()
.connect_timeout(Duration::from_secs(5))
.timeout(Duration::from_secs(300))
.user_agent(APP_USER_AGENT)
.build()?;
let balanced_rpc_tiers = Arc::new(
future::join_all(balanced_rpc_tiers.into_iter().map(|balanced_rpc_tier| {
Web3ProviderTier::try_new(
balanced_rpc_tier,
Some(http_client.clone()),
block_watcher.clone(),
&clock,
)
}))
.await
.into_iter()
.collect::<anyhow::Result<Vec<Web3ProviderTier>>>()?,
);
let private_rpcs = if private_rpcs.is_empty() {
warn!("No private relays configured. Any transactions will be broadcast to the public mempool!");
// TODO: instead of None, set it to a list of all the rpcs from balanced_rpc_tiers. that way we broadcast very loudly
None
} else {
Some(Arc::new(
Web3ProviderTier::try_new(
private_rpcs,
Some(http_client),
block_watcher.clone(),
&clock,
)
.await?,
))
};
let (new_block_sender, mut new_block_receiver) = watch::channel::<String>("".to_string());
{
// TODO: spawn this later?
// spawn a future for the block_watcher
let block_watcher = block_watcher.clone();
tokio::spawn(async move { block_watcher.run(new_block_sender).await });
}
{
// spawn a future for sorting our synced rpcs
// TODO: spawn this later?
let balanced_rpc_tiers = balanced_rpc_tiers.clone();
let private_rpcs = private_rpcs.clone();
let block_watcher = block_watcher.clone();
tokio::spawn(async move {
let mut tier_map = HashMap::new();
let mut private_map = HashMap::new();
for balanced_rpc_tier in balanced_rpc_tiers.iter() {
for rpc in balanced_rpc_tier.clone_rpcs() {
tier_map.insert(rpc, balanced_rpc_tier);
}
}
if let Some(private_rpcs) = private_rpcs {
for rpc in private_rpcs.clone_rpcs() {
private_map.insert(rpc, private_rpcs.clone());
}
}
while new_block_receiver.changed().await.is_ok() {
let updated_rpc = new_block_receiver.borrow().clone();
if let Some(tier) = tier_map.get(&updated_rpc) {
tier.update_synced_rpcs(block_watcher.clone(), allowed_lag)
.unwrap();
} else if let Some(tier) = private_map.get(&updated_rpc) {
tier.update_synced_rpcs(block_watcher.clone(), allowed_lag)
.unwrap();
} else {
panic!("howd this happen");
}
}
});
}
Ok(Web3ProxyApp {
clock,
balanced_rpc_tiers,
private_rpcs,
balanced_rpc_ratelimiter_lock: Default::default(),
private_rpcs_ratelimiter_lock: Default::default(),
})
}
/// send the request to the approriate RPCs
/// TODO: dry this up
async fn proxy_web3_rpc(
self: Arc<Web3ProxyApp>,
json_body: JsonRpcRequest,
) -> anyhow::Result<impl warp::Reply> {
if self.private_rpcs.is_some() && json_body.method == "eth_sendRawTransaction" {
let private_rpcs = self.private_rpcs.as_ref().unwrap();
// there are private rpcs configured and the request is eth_sendSignedTransaction. send to all private rpcs
loop {
// TODO: think more about this lock. i think it won't actually help the herd. it probably makes it worse if we have a tight lag_limit
let read_lock = self.private_rpcs_ratelimiter_lock.read().await;
match private_rpcs.get_upstream_servers().await {
Ok(upstream_servers) => {
let (tx, mut rx) = mpsc::unbounded_channel();
let connections = private_rpcs.clone_connections();
let method = json_body.method.clone();
let params = json_body.params.clone();
tokio::spawn(async move {
connections
.try_send_requests(upstream_servers, method, params, tx)
.await
});
// wait for the first response
let response = rx
.recv()
.await
.ok_or_else(|| anyhow::anyhow!("no successful response"))?;
if let Ok(partial_response) = response {
let response = json!({
"jsonrpc": "2.0",
"id": json_body.id,
"result": partial_response
});
return Ok(warp::reply::json(&response));
}
}
Err(not_until) => {
// TODO: move this to a helper function
// sleep (with a lock) until our rate limits should be available
drop(read_lock);
if let Some(not_until) = not_until {
let write_lock = self.balanced_rpc_ratelimiter_lock.write().await;
let deadline = not_until.wait_time_from(self.clock.now());
sleep(deadline).await;
drop(write_lock);
}
}
};
}
} else {
// this is not a private transaction (or no private relays are configured)
// try to send to each tier, stopping at the first success
loop {
let read_lock = self.balanced_rpc_ratelimiter_lock.read().await;
// there are multiple tiers. save the earliest not_until (if any). if we don't return, we will sleep until then and then try again
let mut earliest_not_until = None;
for balanced_rpcs in self.balanced_rpc_tiers.iter() {
// TODO: what allowed lag?
match balanced_rpcs.next_upstream_server().await {
Ok(upstream_server) => {
let connections = balanced_rpcs.connections();
let response = connections
.try_send_request(
upstream_server,
json_body.method.clone(),
json_body.params.clone(),
)
.await;
let response = match response {
Ok(partial_response) => {
// TODO: trace here was really slow with millions of requests.
// info!("forwarding request from {}", upstream_server);
json!({
// TODO: re-use their jsonrpc?
"jsonrpc": json_body.jsonrpc,
"id": json_body.id,
"result": partial_response
})
}
Err(e) => {
// TODO: what is the proper format for an error?
json!({
"jsonrpc": json_body.jsonrpc,
"id": json_body.id,
"error": format!("{}", e)
})
}
};
return Ok(warp::reply::json(&response));
}
Err(None) => {
warn!("No servers in sync!");
}
Err(Some(not_until)) => {
// save the smallest not_until. if nothing succeeds, return an Err with not_until in it
// TODO: helper function for this
if earliest_not_until.is_none() {
earliest_not_until.replace(not_until);
} else {
let earliest_possible =
earliest_not_until.as_ref().unwrap().earliest_possible();
let new_earliest_possible = not_until.earliest_possible();
if earliest_possible > new_earliest_possible {
earliest_not_until = Some(not_until);
}
}
}
}
}
// we haven't returned an Ok, sleep and try again
// TODO: move this to a helper function
drop(read_lock);
// unwrap should be safe since we would have returned if it wasn't set
if let Some(earliest_not_until) = earliest_not_until {
let write_lock = self.balanced_rpc_ratelimiter_lock.write().await;
let deadline = earliest_not_until.wait_time_from(self.clock.now());
sleep(deadline).await;
drop(write_lock);
} else {
// TODO: how long should we wait?
// TODO: max wait time?
sleep(Duration::from_millis(500)).await;
};
}
}
}
}
#[tokio::main]
async fn main() {
// install global collector configured based on RUST_LOG env var.
tracing_subscriber::fmt::init();
// TODO: load the config from yaml instead of hard coding
// TODO: support multiple chains in one process? then we could just point "chain.stytt.com" at this and caddy wouldn't need anything else
// TODO: be smart about about using archive nodes? have a set that doesn't use archive nodes since queries to them are more valuable
let listen_port = 8445;
// TODO: what should this be? 0 will cause a thundering herd
let allowed_lag = 0;
let state = Web3ProxyApp::try_new(
allowed_lag,
vec![
// local nodes
vec![("ws://10.11.12.16:8545", 0), ("ws://10.11.12.16:8946", 0)],
// paid nodes
// TODO: add paid nodes (with rate limits)
// vec![
// // chainstack.com archive
// (
// "wss://ws-nd-373-761-850.p2pify.com/106d73af4cebc487df5ba92f1ad8dee7",
// 0,
// ),
// ],
// free nodes
// vec![
// // ("https://main-rpc.linkpool.io", 0), // linkpool is slow and often offline
// ("https://rpc.ankr.com/eth", 0),
// ],
],
vec![
// ("https://api.edennetwork.io/v1/beta", 0),
// ("https://api.edennetwork.io/v1/", 0),
],
)
.await
.unwrap();
let state: Arc<Web3ProxyApp> = Arc::new(state);
let proxy_rpc_filter = warp::any()
.and(warp::post())
.and(warp::body::json())
.then(move |json_body| state.clone().proxy_web3_rpc(json_body));
// TODO: filter for displaying connections and their block heights
// TODO: warp trace is super verbose. how do we make this more readable?
// let routes = proxy_rpc_filter.with(warp::trace::request());
let routes = proxy_rpc_filter.map(handle_anyhow_errors);
warp::serve(routes).run(([0, 0, 0, 0], listen_port)).await;
}
/// convert result into an http response. use this at the end of your warp filter
pub fn handle_anyhow_errors<T: warp::Reply>(res: anyhow::Result<T>) -> Box<dyn warp::Reply> {
match res {
Ok(r) => Box::new(r.into_response()),
Err(e) => Box::new(warp::reply::with_status(
format!("{}", e),
reqwest::StatusCode::INTERNAL_SERVER_ERROR,
)),
}
}