Watch multiple consul nodes

3 files changed, 129 insertions, 26 deletions

diff --git a/src/consul.rs b/src/consul.rs
index 6fc031c..240c177 100644
--- a/src/consul.rs
+++ b/src/consul.rs
@@ -7,6 +7,12 @@ use reqwest::StatusCode;
 use serde::{Deserialize, Serialize};
 
 // ---- Watch and retrieve Consul catalog ----
+//
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ConsulNodeListNode {
+	#[serde(rename = "Node")]
+	pub node: String,
+}
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct ConsulServiceEntry {
@@ -59,8 +65,6 @@ pub struct Consul {
 	url: String,
 	kv_prefix: String,
 
-	idx: Option<u64>,
-
 	pub local_node: String,
 }
 
@@ -70,29 +74,36 @@ impl Consul {
 			client: reqwest::Client::new(),
 			url: url.to_string(),
 			kv_prefix: kv_prefix.to_string(),
-			idx: None,
 			local_node: local_node.into(),
 		};
 	}
 
-	pub fn watch_node_reset(&mut self) -> () {
-		self.idx = None;
+	pub async fn list_nodes(&self) -> Result<Vec<String>> {
+		debug!("list_nodes");
+
+		let url = format!("{}/v1/catalog/nodes", self.url);
+
+		let http = self.client.get(&url).send().await?;
+		let resp: Vec<ConsulNodeListNode> = http.json().await?;
+		Ok(resp.into_iter().map(|n| n.node).collect::<Vec<_>>())
 	}
 
-	pub async fn watch_node(&mut self, host: &str) -> Result<ConsulNodeCatalog> {
-		let url = match self.idx {
+	pub async fn watch_node(&self, host: &str, idx: Option<usize>) -> Result<(ConsulNodeCatalog, usize)> {
+		debug!("watch_node {} {:?}", host, idx);
+
+		let url = match 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 new_idx = match http.headers().get("X-Consul-Index") {
+			Some(v) => v.to_str()?.parse::<usize>()?,
+			None => bail!("X-Consul-Index header not found"),
 		};
 
 		let resp: ConsulNodeCatalog = http.json().await?;
-		return Ok(resp);
+		return Ok((resp, new_idx));
 	}
 
 	// ---- KV get and put ----
diff --git a/src/main.rs b/src/main.rs
index 9d710b2..4a0c0ec 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,8 @@
 #[macro_use]
 extern crate anyhow;
 
+use structopt::StructOpt;
+
 mod cert;
 mod cert_store;
 mod consul;
@@ -11,15 +13,34 @@ mod reverse_proxy;
 
 use log::*;
 
+#[derive(StructOpt, Debug)]
+#[structopt(name = "tricot")]
+struct Opt {
+	/// Address of consul server
+	#[structopt(long = "consul-addr", env = "TRICOT_CONSUL_HOST", default_value = "http://127.0.0.1:8500/")]
+	pub consul_addr: String,
+
+	/// Prefix of Tricot's entries in Consul KV space
+	#[structopt(long = "consul-kv-prefix", env = "TRICOT_CONSUL_KV_PREFIX", default_value = "tricot/")]
+	pub consul_kv_prefix: String,
+
+	/// Node name
+	#[structopt(long = "node-name", env = "TRICOT_NODE_NAME", default_value = "<none>")]
+	pub node_name: String,
+}
+
 #[tokio::main(flavor = "multi_thread", worker_threads = 10)]
 async fn main() {
 	if std::env::var("RUST_LOG").is_err() {
 		std::env::set_var("RUST_LOG", "tricot=debug")
 	}
 	pretty_env_logger::init();
+
+	let opt = Opt::from_args();
+
 	info!("Starting Tricot");
 
-	let consul = consul::Consul::new("http://10.42.0.21:8500", "tricot/", "carcajou");
+	let consul = consul::Consul::new(&opt.consul_addr, &opt.consul_kv_prefix, &opt.node_name);
 	let mut rx_proxy_config = proxy_config::spawn_proxy_config_task(consul.clone());
 
 	let cert_store = cert_store::CertStore::new(consul.clone());
diff --git a/src/proxy_config.rs b/src/proxy_config.rs
index ba58484..31a2659 100644
--- a/src/proxy_config.rs
+++ b/src/proxy_config.rs
@@ -1,7 +1,13 @@
 use std::net::SocketAddr;
 use std::sync::{atomic, Arc};
+use std::collections::HashMap;
 use std::{cmp, time::Duration};
 
+use anyhow::Result;
+
+use futures::stream::{FuturesUnordered, StreamExt};
+use futures::future::{BoxFuture};
+
 use log::*;
 use tokio::{sync::watch, time::sleep};
 
@@ -63,7 +69,7 @@ fn parse_tricot_tag(target_addr: SocketAddr, tag: &str) -> Option<ProxyEntry> {
 	})
 }
 
-fn parse_consul_catalog(catalog: &ConsulNodeCatalog) -> ProxyConfig {
+fn parse_consul_catalog(catalog: &ConsulNodeCatalog) -> Vec<ProxyEntry> {
 	let mut entries = vec![];
 
 	for (_, svc) in catalog.services.iter() {
@@ -79,37 +85,102 @@ fn parse_consul_catalog(catalog: &ConsulNodeCatalog) -> ProxyConfig {
 		}
 	}
 
-	ProxyConfig { entries }
+	entries
 }
 
-pub fn spawn_proxy_config_task(mut consul: Consul) -> watch::Receiver<Arc<ProxyConfig>> {
+#[derive(Default)]
+struct NodeWatchState {
+	last_idx: Option<usize>,
+	last_catalog: Option<ConsulNodeCatalog>,
+	retries: u32,
+}
+
+pub fn spawn_proxy_config_task(consul: Consul) -> watch::Receiver<Arc<ProxyConfig>> {
 	let (tx, rx) = watch::channel(Arc::new(ProxyConfig {
 		entries: Vec::new(),
 	}));
+	
+	let consul = Arc::new(consul);
 
 	tokio::spawn(async move {
-		let mut retries = 0;
-		let node = consul.local_node.clone();
+		let mut nodes = HashMap::new();
+		let mut watches = FuturesUnordered::<BoxFuture<'static, (String, Result<_>)>>::new();
 
 		loop {
-			let catalog = match consul.watch_node(&node).await {
-				Ok(c) => c,
+			match consul.list_nodes().await {
+				Ok(consul_nodes) => {
+					info!("Watched consul nodes: {:?}", consul_nodes);
+					for node in consul_nodes {
+						if !nodes.contains_key(&node) {
+							nodes.insert(node.clone(), NodeWatchState::default());
+
+							let node = node.to_string();
+							let consul = consul.clone();
+
+							watches.push(Box::pin(async move {
+								let res = consul.watch_node(&node, None).await;
+								(node, res)
+							}));
+						}
+					}
+				}
+				Err(e) => {
+					warn!("Could not get Consul node list: {}", e);
+				}
+			}
+
+			let (node, res): (String, Result<_>) = match watches.next().await {
+				Some(v) => v,
+				None => {
+					warn!("No nodes currently watched in proxy_config.rs");
+					sleep(Duration::from_secs(10)).await;
+					continue;
+				}
+			};
+
+			match res {
+				Ok((catalog, new_idx)) => {
+					let mut watch_state = nodes.get_mut(&node).unwrap();
+					watch_state.last_idx = Some(new_idx);
+					watch_state.last_catalog = Some(catalog);
+					watch_state.retries = 0;
+
+					let idx = watch_state.last_idx;
+					let consul = consul.clone();
+					watches.push(Box::pin(async move {
+						let res = consul.watch_node(&node, idx).await;
+						(node, res)
+					}));
+				}
 				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));
+					let mut watch_state = nodes.get_mut(&node).unwrap();
+					watch_state.retries += 1;
+					watch_state.last_idx = None;
+
+					let will_retry_in = retry_to_time(watch_state.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;
+
+					let consul = consul.clone();
+					watches.push(Box::pin(async move {
+						sleep(will_retry_in).await;
+						let res = consul.watch_node(&node, None).await;
+						(node, res)
+					}));
 					continue;
 				}
-			};
-			retries = 0;
+			}
 
-			let config = parse_consul_catalog(&catalog);
+			let mut entries = vec![];
+			for (_, watch_state) in nodes.iter() {
+				if let Some(catalog) = &watch_state.last_catalog {
+					entries.extend(parse_consul_catalog(catalog));
+				}
+			}
+			let config = ProxyConfig { entries };
 			debug!("Extracted configuration: {:#?}", config);
 
 			tx.send(Arc::new(config)).expect("Internal error");