use std::net::SocketAddr;
use std::{cmp, time::Duration};
use log::*;
use tokio::{sync::watch, time::sleep};
use crate::consul::*;
// ---- Extract proxy config from Consul catalog ----
#[derive(Debug)]
pub struct ProxyEntry {
pub target_addr: SocketAddr,
pub host: String,
pub path_prefix: Option<String>,
pub priority: u32,
}
#[derive(Debug)]
pub struct ProxyConfig {
pub entries: Vec<ProxyEntry>,
}
fn retry_to_time(retries: u32, max_time: Duration) -> Duration {
// 1.2^x seems to be a good value to exponentially increase time at a good pace
// eg. 1.2^32 = 341 seconds ~= 5 minutes - ie. after 32 retries we wait 5
// minutes
return Duration::from_secs(cmp::min(
max_time.as_secs(),
1.2f64.powf(retries as f64) as u64,
));
}
fn parse_tricot_tag(target_addr: SocketAddr, tag: &str) -> Option<ProxyEntry> {
let splits = tag.split(' ').collect::<Vec<_>>();
if (splits.len() != 2 && splits.len() != 3) || splits[0] != "tricot" {
return None;
}
let (host, path_prefix) = match splits[1].split_once('/') {
Some((h, p)) => (h, Some(p.to_string())),
None => (splits[1], None),
};
let priority = match splits.len() {
3 => splits[2].parse().ok()?,
_ => 100,
};
Some(ProxyEntry {
target_addr,
host: host.to_string(),
path_prefix,
priority,
})
}
fn parse_consul_catalog(catalog: &ConsulNodeCatalog) -> ProxyConfig {
let mut entries = vec![];
for (_, svc) in catalog.services.iter() {
let ip_addr = match svc.address.parse() {
Ok(ip) => ip,
_ => continue,
};
let addr = SocketAddr::new(ip_addr, svc.port);
for tag in svc.tags.iter() {
if let Some(ent) = parse_tricot_tag(addr, tag) {
entries.push(ent);
}
}
}
ProxyConfig { entries }
}
pub fn spawn_proxy_config_task(mut consul: Consul, node: &str) -> watch::Receiver<ProxyConfig> {
let (tx, rx) = watch::channel(ProxyConfig {
entries: Vec::new(),
});
let node = node.to_string();
tokio::spawn(async move {
let mut retries = 0;
loop {
let catalog = match consul.watch_node(&node).await {
Ok(c) => c,
Err(e) => {
consul.watch_node_reset();
retries = cmp::min(std::u32::MAX - 1, retries) + 1;
let will_retry_in = retry_to_time(retries, Duration::from_secs(600));
error!(
"Failed to query consul. Will retry in {}s. {}",
will_retry_in.as_secs(),
e
);
sleep(will_retry_in).await;
continue;
}
};
retries = 0;
let config = parse_consul_catalog(&catalog);
debug!("Extracted configuration: {:#?}", config);
tx.send(config).expect("Internal error");
}
});
rx
}