Centralise network interface checks

bibliotecha.sh

@@ -144,13 +144,12 @@ function stop_networking_services {
   systemctl stop ${services}
 }
 
-function configure_network_interfaces {
+function ensure_predictable_network_interfaces {
-  echo "Configuring networking interfaces ..."
+  echo "Ensuring predictable networking interfaces ..."
 
   # shellcheck disable=SC2010
   # shellcheck disable=SC2155
-  ethernet_interface=$(ls /sys/class/net/ | grep en)
+  local ethernet_interface=$(ls /sys/class/net/ | grep en)
-  local ethernet_filename="/etc/network/interfaces.d/${ethernet_interface}"
 
   if [[ -z "${ethernet_interface}" ]]; then
     echo ""
@@ -161,14 +160,9 @@ function configure_network_interfaces {
     exit 1
   fi
 
-  { echo "auto eth0";
-    echo "allow-hotplug ${ethernet_interface}"; 
-    echo "iface ${ethernet_interface} inet dhcp"; } > "${ethernet_filename}"
-
   # shellcheck disable=SC2010
   # shellcheck disable=SC2155
   local wireless_interface=$(ls /sys/class/net/ | grep wl)
-  local wireless_filename="/etc/network/interfaces.d/${wireless_interface}"
 
   if [[ -z "${wireless_interface}" ]]; then
     echo ""
@@ -178,6 +172,24 @@ function configure_network_interfaces {
     echo ""
     exit 1
   fi
+}
+
+function configure_network_interfaces {
+  echo "Configuring networking interfaces ..."
+
+  # shellcheck disable=SC2010
+  # shellcheck disable=SC2155
+  local ethernet_interface=$(ls /sys/class/net/ | grep en)
+  local ethernet_filename="/etc/network/interfaces.d/${ethernet_interface}"
+
+  { echo "auto eth0";
+    echo "allow-hotplug ${ethernet_interface}";
+    echo "iface ${ethernet_interface} inet dhcp"; } > "${ethernet_filename}"
+
+  # shellcheck disable=SC2010
+  # shellcheck disable=SC2155
+  local wireless_interface=$(ls /sys/class/net/ | grep wl)
+  local wireless_filename="/etc/network/interfaces.d/${wireless_interface}"
 
   { echo "auto ${wireless_interface}";
     echo "iface ${wireless_interface} inet static";
@@ -193,15 +205,6 @@ function configure_dnsmasq {
   local wireless_interface=$(ls /sys/class/net/ | grep wl)
   local wireless_filename="/etc/dnsmasq.d/${wireless_interface}.conf"
 
-  if [[ -z "${wireless_interface}" ]]; then
-    echo ""
-    echo "Could not determine the wireless interface"
-    echo "Please ensure you've configure 'predictable network interfaces'"
-    echo "Please see https://manual.bibliotecha.info/#troubleshooting for more"
-    echo ""
-    exit 1
-  fi
-
   { echo "bogus-priv"
     echo "server=/library/10.0.0.1"
     echo "local=/library/"
@@ -222,15 +225,6 @@ function configure_hostapd {
   local wireless_interface=$(ls /sys/class/net/ | grep wl)
   local hostapd_filename="/etc/hostapd/hostapd.conf"
 
-  if [[ -z "${wireless_interface}" ]]; then
-    echo ""
-    echo "Could not determine the wireless interface"
-    echo "Please ensure you've configure 'predictable network interfaces'"
-    echo "Please see https://manual.bibliotecha.info/#troubleshooting for more"
-    echo ""
-    exit 1
-  fi
-
   { echo "interface=${wireless_interface}"
     echo "ssid=Bibliotecha"
     echo "hw_mode=g"
@@ -393,6 +387,7 @@ function run_installation {
 
   install_networking_packages
   stop_networking_services
+  ensure_predictable_network_interfaces
   configure_network_interfaces
   configure_dnsmasq
   configure_hostapd