Properly handle empty catalog (absent node)

Cargo.lock

@@ -114,9 +114,9 @@ dependencies = [
 
 [[package]]
 name = "df-consul"
-version = "0.1.0"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ec5111d5daddfbab491780564dc8270c29c90553fab98d677489600a8623c76"
+checksum = "a351d00f138e768845cdefb9ae27b79aeed97c698745c73bb2805cad1167aa81"
 dependencies = [
  "anyhow",
  "bytes",

Cargo.toml

@@ -12,7 +12,7 @@ anyhow = "1.0.66"
 futures = "0.3"
 tracing = { version = "0.1.30" }
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-df-consul = "0.1.0"
+df-consul = "0.2.0"
 structopt = "0.3"
 tokio = { version = "1.22", default-features = false, features = ["rt", "rt-multi-thread", "io-util", "net", "time", "macros", "sync", "signal", "fs"] }
 reqwest = { version = "0.11", default-features = false, features = ["json", "rustls-tls-webpki-roots" ] }

src/dns_config.rs

@@ -185,7 +185,7 @@ pub fn spawn_dns_config_task(
                 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.last_catalog = catalog;
                     watch_state.retries = 0;
 
                     let idx = watch_state.last_idx;