From d583c17782977c3547da563a62e6f9f4fada15f3 Mon Sep 17 00:00:00 2001
From: Quentin Dufour <quentin@deuxfleurs.fr>
Date: Fri, 22 May 2020 10:33:09 +0200
Subject: [PATCH] We are now able to watch

---
 src/consul.rs | 24 ++++++++++++++++++------
 src/main.rs   |  6 ++++--
 2 files changed, 22 insertions(+), 8 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)
   }
 }
diff --git a/src/main.rs b/src/main.rs
index ead8c32..028f16e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,9 +14,11 @@ async fn main() {
     let diplo = Diplonat::new().await.expect("Setup failed");
     diplo.listen().await.expect("A runtime error occured");
 */
-    let c = Consul::new("http://127.0.0.1:8500");
-    let cn = c.catalog_node("lheureduthe").await.expect("Failed to fetch API");
+    let mut c = Consul::new("http://127.0.0.1:8500");
+    let cn = c.watch_node("lheureduthe").await.expect("Failed to fetch API");
     println!("{:#?}", cn);
+    let cn2 = c.watch_node("lheureduthe").await.expect("Failed to fetch API");
+    println!("{:#?}", cn2);
 
 /*
     let gateway = match search_gateway(Default::default()).await {