From 2f65c4648cbded14225edb1fab0f50b2a5692764 Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Thu, 2 Apr 2026 13:01:42 -0500
Subject: [PATCH] Add /health endpoint and CHECKS file for zero-downtime
 deploys

---
 CHECKS                                               |  5 +++++
 .../controllers/health_controller.ex                 | 12 ++++++++++++
 lib/microwaveprop_web/router.ex                      |  3 +++
 3 files changed, 20 insertions(+)
 create mode 100644 CHECKS
 create mode 100644 lib/microwaveprop_web/controllers/health_controller.ex

diff --git a/CHECKS b/CHECKS
new file mode 100644
index 00000000..3fa14dfb
--- /dev/null
+++ b/CHECKS
@@ -0,0 +1,5 @@
+WAIT=5
+TIMEOUT=60
+ATTEMPTS=3
+
+/health ok
diff --git a/lib/microwaveprop_web/controllers/health_controller.ex b/lib/microwaveprop_web/controllers/health_controller.ex
new file mode 100644
index 00000000..f247b033
--- /dev/null
+++ b/lib/microwaveprop_web/controllers/health_controller.ex
@@ -0,0 +1,12 @@
+defmodule MicrowavepropWeb.HealthController do
+  use MicrowavepropWeb, :controller
+
+  def check(conn, _params) do
+    # Verify DB is reachable
+    Ecto.Adapters.SQL.query!(Microwaveprop.Repo, "SELECT 1")
+
+    conn
+    |> put_resp_content_type("text/plain")
+    |> send_resp(200, "ok")
+  end
+end
diff --git a/lib/microwaveprop_web/router.ex b/lib/microwaveprop_web/router.ex
index ec7d30fe..6bd76b4a 100644
--- a/lib/microwaveprop_web/router.ex
+++ b/lib/microwaveprop_web/router.ex
@@ -14,6 +14,9 @@ defmodule MicrowavepropWeb.Router do
     plug :accepts, ["json"]
   end
 
+  # Health check — no pipeline, minimal overhead
+  get "/health", MicrowavepropWeb.HealthController, :check
+
   scope "/", MicrowavepropWeb do
     pipe_through :browser