1 files changed, 51 insertions, 0 deletions
diff --git a/get_ip_addr.sh b/get_ip_addr.sh
new file mode 100755
index 0000000..27c948a
--- /dev/null
+++ b/get_ip_addr.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+
+ip_version="$1"
+if [ -z "${ip_version:-}" ] || ([ "$ip_version" != 4 ] && [ "$ip_version" != 6 ]); then
+    echo "Usage: get_ip_addr <4|6>" &>2
+    exit 1
+fi
+
+if [ $ip_version = 4 ]; then
+    curl -4 http://icanhazip.com 2> /dev/null
+    exit 0
+fi
+
+set -eu
+CONN_NAME=${CONN_NAME:-nevis}
+conn_device_name="$(nmcli --fields NAME,DEVICE con show | grep ^$CONN_NAME | sed 's/\s\+/ /g' | cut -d' ' -f 2)"
+if [ -z "${conn_device_name:-}" ]; then
+    echo "Could not find the connection device name for connection: \"$CONN_NAME\"" &>2
+    exit 1
+fi
+
+device_line_no="$(ip addr | grep -En ^[0-9]+:\ $conn_device_name | cut -d':' -f 1)"
+if [ -z "${device_line_no:-}" ]; then
+    echo "Could not find device: \"$conn_device_name\" in output of ip addr" &>2
+    exit 1
+fi
+
+ip_addr_output_for_device="$(ip addr | tail -n +$(($device_line_no + 1)))"
+
+device_no="$(ip addr | tail -n +$device_line_no | head -n 1 | cut -d':' -f 1)"
+next_device_no=$(($device_no + 1))
+next_device_line_no="$(ip addr | grep -En ^${next_device_no}:\ | cut -d':' -f 1)"
+if [ -n "${next_device_line_no:-}" ]; then
+    len=$(($next_device_line_no - ($device_line_no + 1)))
+    ip_addr_output_for_device="$(echo $ip_addr_output_for_device | head -n $len)"
+fi
+
+ipv4_regex="([a-z0-9]{1,3}\.){3}[a-z0-9]{1,3}"
+ipv6_regex="([a-z0-9]{1,4}:){7}[a-z0-9]{1,4}"
+if [ "$ip_version" = "4" ]; then
+    ip_regex="$ipv4_regex"
+else
+    ip_regex="$ipv6_regex"
+fi
+ip="$(echo "$ip_addr_output_for_device" | grep "scope global" | grep -oE $ip_regex | head -n 1)"
+if [ -z "${ip:-}" ]; then
+    echo "Could not find global IP in output of ip addr under device: $conn_device_name ($CONN_NAME)"
+    exit 1
+fi
+
+echo "$ip"