update deps; switch to goutils syslog.

setup_deveth

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+
+ensure_dummy_loaded () {
+    if [ -z "$(lsmod | grep dummy)"]
+    then
+        sudo modprobe dummy
+    fi
+}
+
+maybe_add_device () {
+    DEVICE="${1}"
+    if [ -z "$(ip --brief link | grep ${DEVICE})"]
+    then
+        sudo ip link add ${DEVICE} type dummy
+    fi
+}
+
+add_address () {
+    DEVICE="${1}"
+    ADDR="${2}"
+
+    EXISTING="$(ip --brief addr show "${DEVICE}" | awk '{print $3}')"
+    if [ ! -z "${EXISTING}" ]
+    then
+        if [ "${EXISTING}" == "${ADDR}" ]
+        then
+            return
+        fi
+
+        sudo ip addr flush dev "${DEVICE}"
+    fi
+
+    sudo ip link set dev "${DEVICE}" up
+    sudo ip addr add "${ADDR}" dev "${DEVICE}"
+}
+
+flush_device () {
+    DEVICE="${1}"
+
+    sudo ip addr flush dev "${DEVICE}"
+    sudo ip link set dev "${DEVICE}" down
+}
+
+ensure_dummy_loaded
+maybe_add_device deveth0
+maybe_add_device deveth1
+add_address deveth0 192.168.4.250/24
+flush_device deveth1