1 files changed, 166 insertions, 0 deletions
diff --git a/src/rpc/consul_services.rs b/src/rpc/consul_services.rs
new file mode 100644
index 00000000..461bb195
--- /dev/null
+++ b/src/rpc/consul_services.rs
@@ -0,0 +1,166 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::Read;
+use std::net::{IpAddr, SocketAddr};
+
+use err_derive::Error;
+use serde::{Deserialize, Serialize};
+
+use netapp::NodeID;
+
+use garage_util::config::ConsulServiceConfig;
+
+const META_PREFIX: &str = "fr-deuxfleurs-garagehq";
+
+#[derive(Deserialize, Clone, Debug)]
+struct ConsulQueryEntry {
+	#[serde(rename = "Address")]
+	address: String,
+	#[serde(rename = "ServicePort")]
+	service_port: u16,
+	#[serde(rename = "ServiceMeta")]
+	service_meta: HashMap<String, String>,
+}
+
+#[derive(Serialize, Clone, Debug)]
+struct ConsulPublishService {
+	#[serde(rename = "ID")]
+	service_id: String,
+	#[serde(rename = "Name")]
+	service_name: String,
+	#[serde(rename = "Tags")]
+	tags: Vec<String>,
+	#[serde(rename = "Address")]
+	address: IpAddr,
+	#[serde(rename = "Port")]
+	port: u16,
+	#[serde(rename = "Meta")]
+	meta: HashMap<String, String>,
+}
+
+// ----
+
+pub struct ConsulServiceDiscovery {
+	config: ConsulServiceConfig,
+	client: reqwest::Client,
+}
+
+impl ConsulServiceDiscovery {
+	pub fn new(config: ConsulServiceConfig) -> Result<Self, ConsulError> {
+		let mut builder: reqwest::ClientBuilder = match &config.ca_cert {
+			Some(client_ca) => {
+				let mut ca_cert_buf = vec![];
+				File::open(client_ca)?.read_to_end(&mut ca_cert_buf)?;
+
+				let req: reqwest::ClientBuilder = reqwest::Client::builder()
+					.add_root_certificate(reqwest::Certificate::from_pem(&ca_cert_buf[..])?)
+					.use_rustls_tls();
+
+				if config.tls_skip_verify {
+					req.danger_accept_invalid_certs(true)
+				} else {
+					req
+				}
+			}
+			None => reqwest::Client::builder(),
+		};
+
+		if let Some(token) = &config.consul_http_token {
+			let mut headers = reqwest::header::HeaderMap::new();
+			headers.insert("x-consul-token", reqwest::header::HeaderValue::from_str(&token)?);
+			builder = builder.default_headers(headers);
+		}
+
+		let client = builder.build()?;
+
+		Ok(Self { client, config })
+	}
+
+	// ---- READING FROM CONSUL CATALOG ----
+
+	pub async fn get_consul_services(&self) -> Result<Vec<(NodeID, SocketAddr)>, ConsulError> {
+		let url = format!(
+			"{}/v1/catalog/service/{}",
+			self.config.consul_http_addr, self.config.service_name
+		);
+
+		let req = self.client.get(&url);
+		let http = req.send().await?;
+		let entries: Vec<ConsulQueryEntry> = http.json().await?;
+
+		let mut ret = vec![];
+		for ent in entries {
+			let ip = ent.address.parse::<IpAddr>().ok();
+			let pubkey = ent
+				.service_meta
+				.get(&format!("{}-pubkey", META_PREFIX))
+				.and_then(|k| hex::decode(k).ok())
+				.and_then(|k| NodeID::from_slice(&k[..]));
+			if let (Some(ip), Some(pubkey)) = (ip, pubkey) {
+				ret.push((pubkey, SocketAddr::new(ip, ent.service_port)));
+			} else {
+				warn!(
+					"Could not process node spec from Consul: {:?} (invalid IP or public key)",
+					ent
+				);
+			}
+		}
+		debug!("Got nodes from Consul: {:?}", ret);
+
+		Ok(ret)
+	}
+
+	// ---- PUBLISHING TO CONSUL CATALOG ----
+
+	pub async fn publish_consul_service(
+		&self,
+		node_id: NodeID,
+		hostname: &str,
+		rpc_public_addr: SocketAddr,
+	) -> Result<(), ConsulError> {
+		let node = format!("garage:{}", hex::encode(&node_id[..8]));
+
+		let tags = [
+			vec!["advertised-by-garage".into(), hostname.into()],
+			self.config.tags.clone(),
+		]
+		.concat();
+
+		let advertisement: ConsulPublishService = ConsulPublishService {
+			service_id: node.clone(),
+			service_name: self.config.service_name.clone(),
+			tags,
+			meta: [
+				(format!("{}-pubkey", META_PREFIX), hex::encode(node_id)),
+				(format!("{}-hostname", META_PREFIX), hostname.to_string()),
+			]
+			.iter()
+			.cloned()
+			.collect(),
+			address: rpc_public_addr.ip(),
+			port: rpc_public_addr.port(),
+		};
+
+		let url = format!(
+			"{}/v1/agent/service/register?replace-existing-checks",
+			self.config.consul_http_addr
+		);
+
+		let req = self.client.put(&url);
+		let http = req.json(&advertisement).send().await?;
+		http.error_for_status()?;
+
+		Ok(())
+	}
+}
+
+/// Regroup all Consul discovery errors
+#[derive(Debug, Error)]
+pub enum ConsulError {
+	#[error(display = "IO error: {}", _0)]
+	Io(#[error(source)] std::io::Error),
+	#[error(display = "HTTP error: {}", _0)]
+	Reqwest(#[error(source)] reqwest::Error),
+	#[error(display = "Invalid HTTP header error: {}", _0)]
+	HeaderValue(#[error(source)] reqwest::header::InvalidHeaderValue),
+}