adding nm4bond

shell/nm4bond.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+#
+# Create a bond interface on RHEL7 / CentOS7 using pure nmcli methods
+# on a fresh installation (or vanilla networking) that was built using
+# NetworkManager. IPv4 only.
+#
+# Required: first parameter passed is the fully configured interface with
+# IP(s)/CIDR, Gateway and DNS; these values will be extracted and applied
+# to the new bond0 and set as a default route
+#
+# SPDX-License-Identifier: MIT
+
+if [ $# -ne 3 ]; then
+  echo "Usage:   $0 <bond name> <1st slave> <2nd slave>"
+  echo "Example: $0 bond0 eth0 eth1"
+  exit 1
+fi
+
+BOND=$1
+SLAVE1=$2
+SLAVE2=$3
+
+# Build the basic bond in HA mode (most common)
+nmcli con add autoconnect yes type bond con-name "${BOND}" ifname "${BOND}" \
+  mode active-backup miimon 100
+
+# Set a high priority to keep gateway as the default route
+nmcli con mod "${BOND}" connection.autoconnect-priority 99 \
+  ipv6.method link-local
+
+# Pull existing IPv4
+# shellcheck disable=SC2207
+IPV4=($(nmcli -f \
+  ipv4.method,ipv4.addresses,ipv4.gateway,ipv4.dns,ipv4.dns-search \
+  con show "${SLAVE1}" | awk '{print $2}'))
+
+# Configure the bond
+# shellcheck disable=SC2086
+nmcli con mod "${BOND}" ipv4.method ${IPV4[0]} \
+  ipv4.addresses ${IPV4[1]} ipv4.gateway ${IPV4[2]} \
+  ipv4.dns ${IPV4[3]} ipv4.dns-search ${IPV4[4]} \
+  ipv4.never-default no ipv4.ignore-auto-dns no
+
+# Remove then add the interfaces as slaves
+nmcli con del "${SLAVE1}"
+nmcli con add autoconnect yes type bond-slave \
+  con-name "${SLAVE1}" ifname "${SLAVE1}" master "${BOND}"
+
+nmcli con del "${SLAVE2}"
+nmcli con add autoconnect yes type bond-slave \
+  con-name "${SLAVE2}" ifname "${SLAVE2}" master "${BOND}"
+
+exit 0