Fix migration init container env vars and ConnectionMonitor crash

- Add missing env vars to migration init container (PHX_HOST, PORT,
  APRS_PORT, APRS_CALLSIGN, APRS_PASSCODE) so runtime.exs config
  provider doesn't fail due to Kubernetes service discovery injecting
  APRS_PORT as a full URL
- Guard ConnectionMonitor.accepting_connections?/0 with Process.whereis
  to avoid crashing when the GenServer isn't started (e.g. cluster
  enabled but no libcluster topologies configured)

k8s/deployment.yaml

@@ -48,6 +48,14 @@ spec:
               value: "prod"
             - name: SKIP_DB_CREATE
               value: "true"
+            - name: PHX_HOST
+              value: "aprs.me"
+            - name: PORT
+              value: "4000"
+            - name: APRS_PORT
+              value: "10152"
+            - name: APRS_CALLSIGN
+              value: "w5isp-1"
             - name: RELEASE_COOKIE
               valueFrom:
                 secretKeyRef:
@@ -58,6 +66,11 @@ spec:
                 secretKeyRef:
                   name: aprs-secrets
                   key: SECRET_KEY_BASE
+            - name: APRS_PASSCODE
+              valueFrom:
+                secretKeyRef:
+                  name: aprs-secrets
+                  key: APRS_PASSCODE
           envFrom:
             - secretRef:
                 name: aprs-db

lib/aprsme/connection_monitor.ex

@@ -66,7 +66,7 @@ defmodule Aprsme.ConnectionMonitor do
   Check if this node should accept new connections
   """
   def accepting_connections? do
-    if cluster_enabled?() do
+    if cluster_enabled?() and Process.whereis(__MODULE__) != nil do
       GenServer.call(__MODULE__, :accepting_connections?)
     else
       true