1 files changed, 18 insertions, 6 deletions
diff --git a/src/consul.rs b/src/consul.rs
index e438605..b06f62d 100644
--- a/src/consul.rs
+++ b/src/consul.rs
@@ -1,6 +1,6 @@
 use serde::{Serialize, Deserialize};
 use std::collections::HashMap;
-use anyhow::Result;
+use anyhow::{Result, anyhow};
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct ServiceEntry {
@@ -14,20 +14,32 @@ pub struct CatalogNode {
 
 pub struct Consul {
   client: reqwest::Client,
-  url: String
+  url: String,
+  idx: Option<u64>
 }
 
 impl Consul {
   pub fn new(url: &str) -> Self {
     return Self {
       client: reqwest::Client::new(),
-      url: url.to_string()
+      url: url.to_string(),
+      idx: None
     };
   }
 
-  pub async fn catalog_node(&self, host: &str) -> Result<CatalogNode> {
-    let url = format!("{}/v1/catalog/node/{}", self.url, host);
-    let resp: CatalogNode = self.client.get(&url).send().await?.json().await?;
+  pub async fn watch_node(&mut self, host: &str) -> Result<CatalogNode> {
+    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: CatalogNode = http.json().await?;
     return Ok(resp)
   }
 }