From da42d6449448d7e1936f9d938a44268f258704a2 Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Fri, 2 Jan 2026 15:29:02 -0600
Subject: [PATCH] cluster

---
 config/runtime.exs          | 13 +++++++++++++
 k8s/deployment.yaml         | 20 ++++++++++++++++++++
 k8s/kustomization.yaml      |  1 +
 k8s/service-headless.yaml   | 17 +++++++++++++++++
 lib/towerops/application.ex |  3 +++
 mix.exs                     |  1 +
 mix.lock                    |  1 +
 7 files changed, 56 insertions(+)
 create mode 100644 k8s/service-headless.yaml

diff --git a/config/runtime.exs b/config/runtime.exs
index 36e82781..1aced7a9 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -46,6 +46,19 @@ if config_env() == :prod do
 
   host = System.get_env("PHX_HOST") || "example.com"
 
+  config :libcluster,
+    topologies: [
+      k8s: [
+        strategy: Cluster.Strategy.Kubernetes.DNS,
+        config: [
+          service: "towerops-headless",
+          application_name: "towerops",
+          namespace: "towerops",
+          polling_interval: 10_000
+        ]
+      ]
+    ]
+
   config :towerops, Towerops.Repo,
     # ssl: true,
     url: database_url,
diff --git a/k8s/deployment.yaml b/k8s/deployment.yaml
index 96ac0bd8..45eb8a98 100644
--- a/k8s/deployment.yaml
+++ b/k8s/deployment.yaml
@@ -23,7 +23,27 @@ spec:
         ports:
         - containerPort: 4000
           name: http
+        - containerPort: 4369
+          name: epmd
+        - containerPort: 9000
+          name: dist
         env:
+        - name: POD_IP
+          valueFrom:
+            fieldRef:
+              fieldPath: status.podIP
+        - name: POD_NAME
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.name
+        - name: POD_NAMESPACE
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.namespace
+        - name: RELEASE_DISTRIBUTION
+          value: "name"
+        - name: RELEASE_NODE
+          value: "towerops@$(POD_IP)"
         - name: PORT
           value: "4000"
         - name: PHX_HOST
diff --git a/k8s/kustomization.yaml b/k8s/kustomization.yaml
index 00a392e4..37dff34c 100644
--- a/k8s/kustomization.yaml
+++ b/k8s/kustomization.yaml
@@ -5,5 +5,6 @@ resources:
   - namespace.yaml
   - deployment.yaml
   - service.yaml
+  - service-headless.yaml
   - certificate.yaml
   - ingressroute.yaml
diff --git a/k8s/service-headless.yaml b/k8s/service-headless.yaml
new file mode 100644
index 00000000..b9cd2349
--- /dev/null
+++ b/k8s/service-headless.yaml
@@ -0,0 +1,17 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: towerops-headless
+  namespace: towerops
+spec:
+  clusterIP: None
+  selector:
+    app: towerops
+  ports:
+  - name: epmd
+    port: 4369
+    targetPort: 4369
+  - name: dist
+    port: 9000
+    targetPort: 9000
diff --git a/lib/towerops/application.ex b/lib/towerops/application.ex
index 3a961c48..78d680d9 100644
--- a/lib/towerops/application.ex
+++ b/lib/towerops/application.ex
@@ -7,7 +7,10 @@ defmodule Towerops.Application do
 
   @impl true
   def start(_type, _args) do
+    topologies = Application.get_env(:libcluster, :topologies, [])
+
     children = [
+      {Cluster.Supervisor, [topologies, [name: Towerops.ClusterSupervisor]]},
       ToweropsWeb.Telemetry,
       Towerops.Repo,
       {DNSCluster, query: Application.get_env(:towerops, :dns_cluster_query) || :ignore},
diff --git a/mix.exs b/mix.exs
index 985a8726..5633ad3a 100644
--- a/mix.exs
+++ b/mix.exs
@@ -61,6 +61,7 @@ defmodule Towerops.MixProject do
       {:gettext, "~> 1.0"},
       {:jason, "~> 1.2"},
       {:dns_cluster, "~> 0.2.0"},
+      {:libcluster, "~> 3.4"},
       {:bandit, "~> 1.5"},
       {:styler, "~> 1.10", only: [:dev, :test], runtime: false}
     ]
diff --git a/mix.lock b/mix.lock
index d792cf37..463d8e0b 100644
--- a/mix.lock
+++ b/mix.lock
@@ -20,6 +20,7 @@
   "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~> 0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "lazy_html": {:hex, :lazy_html, "0.1.8", "677a8642e644eef8de98f3040e2520d42d0f0f8bd6c5cd49db36504e34dffe91", [:make, :mix], [{:cc_precompiler, "~> 0.1", [hex: :cc_precompiler, repo: "hexpm", optional: false]}, {:elixir_make, "~> 0.9.0", [hex: :elixir_make, repo: "hexpm", optional: false]}, {:fine, "~> 0.1.0", [hex: :fine, repo: "hexpm", optional: false]}], "hexpm", "0d8167d930b704feb94b41414ca7f5779dff9bca7fcf619fcef18de138f08736"},
+  "libcluster": {:hex, :libcluster, "3.5.0", "5ee4cfde4bdf32b2fef271e33ce3241e89509f4344f6c6a8d4069937484866ba", [:mix], [{:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:telemetry, "~> 1.3", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "ebf6561fcedd765a4cd43b4b8c04b1c87f4177b5fb3cbdfe40a780499d72f743"},
   "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
   "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
   "nimble_options": {:hex, :nimble_options, "1.1.1", "e3a492d54d85fc3fd7c5baf411d9d2852922f66e69476317787a7b2bb000a61b", [:mix], [], "hexpm", "821b2470ca9442c4b6984882fe9bb0389371b8ddec4d45a9504f00a66f650b44"},