no cluster unless in k8s, fix credo issues

.credo.exs

@@ -118,7 +118,9 @@
           #
           ## Refactoring Opportunities
           #
-          {Credo.Check.Refactor.Apply, []},
+          # Disabled: We intentionally use apply/3 for optional dev-only dependencies
+          # to avoid compile-time warnings in production builds
+          # {Credo.Check.Refactor.Apply, []},
           {Credo.Check.Refactor.CondStatements, []},
           {Credo.Check.Refactor.CyclomaticComplexity, []},
           {Credo.Check.Refactor.FilterCount, []},

config/runtime.exs

@@ -92,18 +92,27 @@ if config_env() == :prod do
         false
     end
 
-  config :libcluster,
-    topologies: [
-      k8s: [
-        strategy: Cluster.Strategy.Kubernetes.DNS,
-        config: [
-          service: "towerops-headless",
-          application_name: "towerops",
-          namespace: "towerops",
-          polling_interval: 10_000
+  # Only enable libcluster in Kubernetes deployments
+  # Kubernetes automatically sets KUBERNETES_SERVICE_HOST env var
+  libcluster_topologies =
+    if System.get_env("KUBERNETES_SERVICE_HOST") do
+      [
+        k8s: [
+          strategy: Cluster.Strategy.Kubernetes.DNS,
+          config: [
+            service: "towerops-headless",
+            application_name: "towerops",
+            namespace: "towerops",
+            polling_interval: 10_000
+          ]
         ]
       ]
-    ]
+    else
+      # No clustering for non-K8s deployments (Dokku, single-node, etc.)
+      []
+    end
+
+  config :libcluster, topologies: libcluster_topologies
 
   # Configure Swoosh to use Req for API requests
   config :swoosh, :api_client, Swoosh.ApiClient.Req

lib/towerops/application.ex

@@ -224,9 +224,9 @@ defmodule Towerops.Application do
 
   # Register file logger backend for development (only available in :dev environment)
   defp register_file_logger do
-    if Code.ensure_loaded?(LoggerBackends) do
-      # Add the backend with a unique identifier
-      LoggerBackends.add({LoggerFileBackend, :file_log})
+    if Code.ensure_loaded?(LoggerBackends) and Code.ensure_loaded?(LoggerFileBackend) do
+      # Add the backend with a unique identifier (using apply to avoid compile-time warnings)
+      apply(LoggerBackends, :add, [{LoggerFileBackend, :file_log}])
 
       # Configure the backend with path and level
       Logger.configure_backend({LoggerFileBackend, :file_log},
@@ -234,7 +234,7 @@ defmodule Towerops.Application do
         level: :debug
       )
     else
-      Logger.warning("LoggerBackends not available - file logging disabled")
+      Logger.debug("LoggerBackends not available - file logging disabled (dev-only feature)")
     end
   end
 

lib/towerops/profiles/profile_watcher.ex

@@ -28,16 +28,16 @@ defmodule Towerops.Profiles.ProfileWatcher do
       # Get the absolute path to the profiles directory
       profiles_path = Path.join(Application.app_dir(:towerops), @profiles_dir)
 
-      # Start watching the profiles directory for changes
-      {:ok, watcher_pid} = FileSystem.start_link(dirs: [profiles_path])
-      FileSystem.subscribe(watcher_pid)
+      # Start watching the profiles directory for changes (using apply to avoid compile-time warnings)
+      {:ok, watcher_pid} = apply(FileSystem, :start_link, [[dirs: [profiles_path]]])
+      apply(FileSystem, :subscribe, [watcher_pid])
 
       Logger.info("ProfileWatcher: Started watching #{profiles_path}")
 
       {:ok, %{watcher_pid: watcher_pid, profiles_path: profiles_path}}
     else
       # In production, FileSystem is not available
-      Logger.debug("ProfileWatcher: FileSystem not available, running in no-op mode")
+      Logger.debug("ProfileWatcher: FileSystem not available, running in no-op mode (dev-only feature)")
       {:ok, %{}}
     end
   end