feat: support providing external servers (#631)

* feat(shulker-crds): add external_servers to cluster

* feat(shulker-operator): create configmap with external servers and mount on proxies

* feat(shulker-proxy-agent): watch external servers and register them

* style: fix lint

kube/helm/templates/crds/shulkermc.io_minecraftclusters.yaml

@@ -23,6 +23,28 @@ spec:
         properties:
           spec:
             properties:
+              externalServers:
+                description: List of servers that should be registered on the proxies that are not managed by Shulker
+                items:
+                  properties:
+                    address:
+                      description: Address of the server, may contain a port after a colon
+                      type: string
+                    name:
+                      description: Name of the server, as the proxies will register it. Allowed names only are lowercased, dash-separated alphanumerical string
+                      pattern: ^[a-z0-9\-]+$
+                      type: string
+                    tags:
+                      description: Tags associated to the server
+                      items:
+                        type: string
+                      type: array
+                  required:
+                  - address
+                  - name
+                  type: object
+                nullable: true
+                type: array
               networkAdmins:
                 description: List of player UUIDs that are automatically promoted as network administrators, which are granted all the permissions by default on all the proxies and servers
                 items:

packages/shulker-crds/src/v1alpha1/minecraft_cluster.rs

@@ -24,6 +24,11 @@ pub struct MinecraftClusterSpec {
     /// for the different Shulker components
     #[serde(skip_serializing_if = "Option::is_none")]
     pub redis: Option<MinecraftClusterRedisSpec>,
+
+    /// List of servers that should be registered on the proxies
+    /// that are not managed by Shulker
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub external_servers: Option<Vec<MinecraftClusterExternalServerSpec>>,
 }
 
 #[derive(Deserialize, Serialize, Clone, Debug, Default, JsonSchema)]
@@ -72,6 +77,23 @@ impl MinecraftClusterRedisProvidedSpec {
     }
 }
 
+#[derive(Deserialize, Serialize, Clone, Debug, Default, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct MinecraftClusterExternalServerSpec {
+    /// Name of the server, as the proxies will register it.
+    /// Allowed names only are lowercased, dash-separated
+    /// alphanumerical string
+    #[schemars(regex(pattern = r"^[a-z0-9\-]+$"))]
+    pub name: String,
+
+    /// Address of the server, may contain a port after a colon
+    pub address: String,
+
+    /// Tags associated to the server
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub tags: Vec<String>,
+}
+
 /// The status object of `MinecraftCluster`
 #[derive(Deserialize, Serialize, Clone, Debug, JsonSchema)]
 #[serde(rename_all = "camelCase")]

packages/shulker-operator/src/reconcilers/minecraft_cluster/external_servers_config_map.rs

@@ -0,0 +1,110 @@
+use std::collections::BTreeMap;
+
+use k8s_openapi::api::core::v1::ConfigMap;
+use kube::core::ObjectMeta;
+use kube::Api;
+use kube::Client;
+use kube::ResourceExt;
+
+use shulker_crds::v1alpha1::minecraft_cluster::MinecraftCluster;
+use shulker_kube_utils::reconcilers::builder::ResourceBuilder;
+
+use super::MinecraftClusterReconciler;
+
+pub struct ExternalServersConfigMapBuilder {
+    client: Client,
+}
+
+#[async_trait::async_trait]
+impl<'a> ResourceBuilder<'a> for ExternalServersConfigMapBuilder {
+    type OwnerType = MinecraftCluster;
+    type ResourceType = ConfigMap;
+    type Context = ();
+
+    fn name(cluster: &Self::OwnerType) -> String {
+        format!("{}-external-servers", cluster.name_any())
+    }
+
+    fn api(&self, cluster: &Self::OwnerType) -> kube::Api<Self::ResourceType> {
+        Api::namespaced(self.client.clone(), cluster.namespace().as_ref().unwrap())
+    }
+
+    fn is_needed(&self, cluster: &Self::OwnerType) -> bool {
+        cluster
+            .spec
+            .external_servers
+            .as_ref()
+            .map_or(false, |list| !list.is_empty())
+    }
+
+    async fn build(
+        &self,
+        cluster: &Self::OwnerType,
+        name: &str,
+        _existing_config_map: Option<&Self::ResourceType>,
+        _context: Option<Self::Context>,
+    ) -> Result<Self::ResourceType, anyhow::Error> {
+        let config_map = ConfigMap {
+            metadata: ObjectMeta {
+                name: Some(name.to_string()),
+                namespace: Some(cluster.namespace().unwrap().clone()),
+                labels: Some(MinecraftClusterReconciler::get_labels(
+                    cluster,
+                    "external-servers".to_string(),
+                    "proxy".to_string(),
+                )),
+                ..ObjectMeta::default()
+            },
+            data: Some(BTreeMap::from([(
+                "external-servers.yaml".to_string(),
+                ExternalServersConfigMapBuilder::get_content_from_server_list(cluster),
+            )])),
+            ..ConfigMap::default()
+        };
+
+        Ok(config_map)
+    }
+}
+
+impl ExternalServersConfigMapBuilder {
+    pub fn new(client: Client) -> Self {
+        ExternalServersConfigMapBuilder { client }
+    }
+
+    fn get_content_from_server_list(cluster: &MinecraftCluster) -> String {
+        serde_yaml::to_string(cluster.spec.external_servers.as_ref().unwrap()).unwrap()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use shulker_kube_utils::reconcilers::builder::ResourceBuilder;
+
+    use crate::reconcilers::minecraft_cluster::fixtures::{create_client_mock, TEST_CLUSTER};
+
+    #[test]
+    fn name_contains_cluster_name() {
+        // W
+        let name = super::ExternalServersConfigMapBuilder::name(&TEST_CLUSTER);
+
+        // T
+        assert_eq!(name, "my-cluster-external-servers");
+    }
+
+    #[tokio::test]
+    async fn build_snapshot() {
+        // G
+        let client = create_client_mock();
+        let builder = super::ExternalServersConfigMapBuilder::new(client);
+        let name = super::ExternalServersConfigMapBuilder::name(&TEST_CLUSTER);
+
+        // W
+        let config_map = builder
+            .build(&TEST_CLUSTER, &name, None, None)
+            .await
+            .unwrap();
+
+        // T
+        insta::assert_yaml_snapshot!(config_map);
+    }
+}

packages/shulker-operator/src/reconcilers/minecraft_cluster/fixtures.rs

@@ -2,7 +2,9 @@ use http::{Request, Response};
 use kube::client::Body;
 use kube::{core::ObjectMeta, Client};
 use lazy_static::lazy_static;
-use shulker_crds::v1alpha1::minecraft_cluster::{MinecraftCluster, MinecraftClusterSpec};
+use shulker_crds::v1alpha1::minecraft_cluster::{
+    MinecraftCluster, MinecraftClusterExternalServerSpec, MinecraftClusterSpec,
+};
 
 lazy_static! {
     pub static ref TEST_CLUSTER: MinecraftCluster = MinecraftCluster {
@@ -13,7 +15,12 @@ lazy_static! {
         },
         spec: MinecraftClusterSpec {
             network_admins: None,
-            redis: None
+            redis: None,
+            external_servers: Some(vec![MinecraftClusterExternalServerSpec {
+                name: "my-external-server".to_string(),
+                address: "127.0.0.1:25565".to_string(),
+                tags: vec!["game".to_string()]
+            }])
         },
         status: None,
     };

packages/shulker-operator/src/reconcilers/minecraft_cluster/mod.rs

@@ -1,9 +1,10 @@
 use std::{collections::BTreeMap, sync::Arc, time::Duration};
 
+use external_servers_config_map::ExternalServersConfigMapBuilder;
 use futures::StreamExt;
 use k8s_openapi::api::{
     apps::v1::StatefulSet,
-    core::v1::{Secret, Service, ServiceAccount},
+    core::v1::{ConfigMap, Secret, Service, ServiceAccount},
     rbac::v1::{Role, RoleBinding},
 };
 use kube::{
@@ -35,6 +36,7 @@ use self::{
 
 use super::Result;
 
+pub mod external_servers_config_map;
 mod forwarding_secret;
 mod headless_service;
 mod minecraft_server_role;
@@ -65,6 +67,7 @@ struct MinecraftClusterReconciler {
     minecraft_server_role_binding_builder: MinecraftServerRoleBindingBuilder,
     redis_service_builder: RedisServiceBuilder,
     redis_stateful_set_builder: RedisStatefulSetBuilder,
+    external_servers_config_map_builder: ExternalServersConfigMapBuilder,
 }
 
 impl MinecraftClusterReconciler {
@@ -111,6 +114,13 @@ impl MinecraftClusterReconciler {
         reconcile_builder(&self.redis_stateful_set_builder, cluster.as_ref(), None)
             .await
             .map_err(ReconcilerError::BuilderError)?;
+        reconcile_builder(
+            &self.external_servers_config_map_builder,
+            cluster.as_ref(),
+            None,
+        )
+        .await
+        .map_err(ReconcilerError::BuilderError)?;
 
         Ok(Action::requeue(Duration::from_secs(5 * 60)))
     }
@@ -210,9 +220,15 @@ pub async fn run(client: Client) {
         ),
         redis_service_builder: RedisServiceBuilder::new(client.clone()),
         redis_stateful_set_builder: RedisStatefulSetBuilder::new(client.clone()),
+
+        external_servers_config_map_builder: ExternalServersConfigMapBuilder::new(client.clone()),
     };
 
     Controller::new(clusters_api, Config::default().any_semantic())
+        .owns(
+            Api::<ConfigMap>::all(client.clone()),
+            Config::default().any_semantic(),
+        )
         .owns(
             Api::<Secret>::all(client.clone()),
             Config::default().any_semantic(),

packages/shulker-operator/src/reconcilers/minecraft_cluster/snapshots/shulker_operator__reconcilers__minecraft_cluster__external_servers_config_map__tests__build_snapshot.snap

@@ -0,0 +1,18 @@
+---
+source: packages/shulker-operator/src/reconcilers/minecraft_cluster/external_servers_config_map.rs
+expression: config_map
+---
+apiVersion: v1
+kind: ConfigMap
+data:
+  external-servers.yaml: "- name: my-external-server\n  address: 127.0.0.1:25565\n  tags:\n  - game\n"
+metadata:
+  labels:
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/instance: external-servers-my-cluster
+    app.kubernetes.io/managed-by: shulker-operator
+    app.kubernetes.io/name: external-servers
+    app.kubernetes.io/part-of: cluster-my-cluster
+    minecraftcluster.shulkermc.io/name: my-cluster
+  name: my-cluster-external-servers
+  namespace: default