First commit to Tricot, a replacement for Traefik v1

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Alex 2021-12-06 23:08:22 +01:00
commit 2895a8ae2e
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/target

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Cargo.toml Normal file
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[package]
name = "tricot"
version = "0.1.0"
edition = "2018"
authors = ["Alex Auvolat <alex@adnab.me>"]
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
anyhow = "1.0.28"
envy = "0.4"
futures = "0.3.5"
log = "0.4"
pretty_env_logger = "0.4"
regex = "1"
reqwest = { version = "0.11", features = ["json"] }
serde = { version = "1.0.107", features = ["derive"] }
serde_json = "1.0.53"
tokio = { version = "1.0", default-features = false, features = ["rt", "rt-multi-thread", "io-util", "net", "time", "macros", "sync", "signal", "fs"] }

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all:
clear; cargo build

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hard_tabs = true

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use std::collections::HashMap;
use anyhow::Result;
use log::*;
use serde::{Deserialize, Serialize};
// ---- Watch and retrieve Consul catalog ----
#[derive(Serialize, Deserialize, Debug)]
pub struct ConsulServiceEntry {
#[serde(rename = "Address")]
pub address: String,
#[serde(rename = "Port")]
pub port: u16,
#[serde(rename = "Tags")]
pub tags: Vec<String>,
}
#[derive(Serialize, Deserialize, Debug)]
pub struct ConsulNodeCatalog {
#[serde(rename = "Services")]
pub services: HashMap<String, ConsulServiceEntry>,
}
#[derive(Clone)]
pub struct Consul {
client: reqwest::Client,
url: String,
idx: Option<u64>,
}
impl Consul {
pub fn new(url: &str) -> Self {
return Self {
client: reqwest::Client::new(),
url: url.to_string(),
idx: None,
};
}
pub fn watch_node_reset(&mut self) -> () {
self.idx = None;
}
pub async fn watch_node(&mut self, host: &str) -> Result<ConsulNodeCatalog> {
let url = match self.idx {
Some(i) => format!("{}/v1/catalog/node/{}?index={}", self.url, host, i),
None => format!("{}/v1/catalog/node/{}", self.url, host),
};
let http = self.client.get(&url).send().await?;
self.idx = match http.headers().get("X-Consul-Index") {
Some(v) => Some(v.to_str()?.parse::<u64>()?),
None => return Err(anyhow!("X-Consul-Index header not found")),
};
let resp: ConsulNodeCatalog = http.json().await?;
return Ok(resp);
}
}

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#[macro_use]
extern crate anyhow;
mod consul;
mod proxy_config;
use log::*;
#[tokio::main]
async fn main() {
pretty_env_logger::init();
info!("Starting Tricot");
let consul = consul::Consul::new("http://10.42.0.21:8500");
let mut rx_proxy_config = proxy_config::spawn_proxy_config_task(consul.clone(), "carcajou");
while rx_proxy_config.changed().await.is_ok() {
info!("Proxy config: {:#?}", *rx_proxy_config.borrow());
}
}

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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
}