Refactor auto-boot-ollama-host script into modular structure with separate configuration, network, SSH, and service management modules for improved maintainability and readability

scripts/network.lua

@@ -0,0 +1,63 @@
+-- Network utilities module for auto-boot-ollama-host
+-- Provides port checking and Wake-on-LAN functionality
+
+local socket = require("socket")
+local utils = require("utils")
+
+local network = {}
+
+-- Check if a TCP port is accepting connections within a timeout (seconds)
+function network.port_is_up(host, port, timeout_sec)
+  host = tostring(host or "127.0.0.1")
+  port = tonumber(port or 0) or 0
+  local timeout = tonumber(timeout_sec or 1) or 1
+  if port <= 0 then return false end
+
+  local deadline = socket.gettime() + timeout
+  while socket.gettime() < deadline do
+    local tcp = socket.tcp()
+    if not tcp then return false end
+    tcp:settimeout(1)
+    local ok = tcp:connect(host, port)
+    tcp:close()
+    if ok then return true end
+    socket.sleep(0.5)
+  end
+  return false
+end
+
+-- Convert MAC address string to bytes
+-- "AA:BB:CC:DD:EE:FF" -> 6 bytes
+local function mac_to_bytes(mac)
+  local bytes = {}
+  for byte in mac:gmatch("(%x%x)") do 
+    table.insert(bytes, tonumber(byte, 16)) 
+  end
+  if #bytes ~= 6 then return nil end
+  return string.char(table.unpack(bytes))
+end
+
+-- Send Wake-on-LAN magic packet
+function network.send_wol(mac_str, bcast_ip, port)
+  -- Build magic packet
+  local bytes = {}
+  for byte in mac_str:gmatch("(%x%x)") do 
+    table.insert(bytes, tonumber(byte, 16)) 
+  end
+  if #bytes ~= 6 then return false, "invalid MAC" end
+  
+  local mac = string.char(table.unpack(bytes))
+  local packet = string.rep(string.char(0xFF), 6) .. mac:rep(16)
+
+  -- Create IPv4 UDP socket (udp4 if available), bind to IPv4 wildcard to lock AF_INET
+  local udp = assert((socket.udp4 or socket.udp)())
+  udp:settimeout(2)
+  assert(udp:setsockname("0.0.0.0", 0))       -- force IPv4 family
+  assert(udp:setoption("broadcast", true))    -- allow broadcast
+
+  local ok, err = udp:sendto(packet, bcast_ip, port)
+  udp:close()
+  return ok ~= nil, err
+end
+
+return network