Implement discovering mr_persistence in mr_server

bins/matchmaker/Cargo.toml

@@ -17,7 +17,6 @@ futures = "0.3.17"
 hyper = "0.14.15"
 kube = "0.60.0"
 kube-derive = "0.60.0"
-kube-runtime = "0.60.0"
 log = "0.4.14"
 k8s-openapi = { version = "0.13.1", default-features = false, features = ["v1_20"] }
 rymder = "0.2.2"

libs/server_lib/Cargo.toml

@@ -17,6 +17,8 @@ bevy_rapier2d = { version = "0.11" }
 chrono = "0.4.19"
 env_logger = "0.8.1"
 jwt-compact = { version = "0.5.0", features = ["std", "clock", "with_rsa"], default-features = false }
+kube = "0.60.0"
+k8s-openapi = { version = "0.13.1", default-features = false, features = ["v1_20"] }
 puffin = { version = "0.8.1", optional = true }
 rand = "0.8.4"
 reqwest = "0.11.8"

libs/server_lib/src/kube_discovery.rs

@@ -0,0 +1,28 @@
+use bevy::log;
+use k8s_openapi::api::core::v1::Pod;
+use kube::{api::ListParams, Api, Client};
+use reqwest::Url;
+
+pub async fn discover_persistence() -> Option<Url> {
+    let client = Client::try_default().await.ok()?;
+    log::info!("Kubernetes environment detected, trying to fetch mr-persistence pods...");
+
+    let pods: Api<Pod> = Api::namespaced(client, "default");
+    let lp = ListParams::default()
+        .labels("app=muddle-run,service=mr-persistence")
+        .timeout(0);
+    let pods_list = pods
+        .list(&lp)
+        .await
+        .map_err(|err| {
+            log::warn!("Failed to fetch kubernetes pods: {:?}", err);
+            err
+        })
+        .ok()?;
+
+    let pod_ip = pods_list.items.first()?.status.as_ref()?.pod_ip.as_ref()?;
+    let persistence_url = format!("http://{}:8083", pod_ip).parse().unwrap();
+    log::info!("Using \"{}\" as MUDDLE_PERSISTENCE_URL", persistence_url);
+
+    Some(persistence_url)
+}

libs/server_lib/src/lib.rs

@@ -32,13 +32,15 @@ use mr_shared_lib::{
     registry::IncrementId,
     simulations_per_second, MuddleSharedPlugin,
 };
+use reqwest::Url;
 use std::{
     lazy::SyncLazy,
     time::{Duration, Instant},
 };
 use tokio::sync::mpsc::UnboundedReceiver;
 
 mod game_events;
+mod kube_discovery;
 mod net;
 mod persistence;
 mod player_updates;
@@ -84,7 +86,9 @@ impl Plugin for MuddleServerPlugin {
         builder.add_startup_system(init_level.system());
         builder.add_startup_system(startup.system());
 
-        if let Some(url) = try_parse_from_env!("MUDDLE_PERSISTENCE_URL") {
+        let persistence_url: Option<Url> = try_parse_from_env!("MUDDLE_PERSISTENCE_URL")
+            .or_else(|| TOKIO.block_on(kube_discovery::discover_persistence()));
+        if let Some(url) = persistence_url {
             let config = PersistenceConfig {
                 url,
                 google_web_client_id: std::env::var("MUDDLE_GOOGLE_WEB_CLIENT_ID")