From d134bdc5832266599003235283bd782ed63e7d88 Mon Sep 17 00:00:00 2001
From: Abhay Krishna Arunachalam <arnchlm@amazon.com>
Date: Wed, 13 Sep 2023 09:52:10 -0700
Subject: [PATCH] Allow active network interface to be overriden

---
 .../build/setup_packer_configs.sh             | 53 +++++++++++--------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/projects/kubernetes-sigs/image-builder/build/setup_packer_configs.sh b/projects/kubernetes-sigs/image-builder/build/setup_packer_configs.sh
index fbe039108a..6b3641b2e5 100755
--- a/projects/kubernetes-sigs/image-builder/build/setup_packer_configs.sh
+++ b/projects/kubernetes-sigs/image-builder/build/setup_packer_configs.sh
@@ -151,30 +151,41 @@ env_and_envsubst '$EKSD_NAME' \
 # directory containing the kickstart config
 if [ "$IMAGE_FORMAT" = "ova" ] && \
     ( [ "$IMAGE_OS" = "redhat" ] || ( [ "$IMAGE_OS" = "ubuntu" ] && [ "$IMAGE_OS_VERSION" != "2004" ] )  ); then
-    echo "Finding correct interface for packer temporary http server"
-    ACTIVE_INTERFACE=""
-    if [ "$(uname -s)" = "Linux" ]; then
-        INTERFACES=($(ls /sys/class/net))
-        for interface in "${INTERFACES[@]}"; do
-            if [ "$interface" = "eth0" ] || [ "$interface" = "en0" ] || [ "$interface" = "eno1" ]; then
-                ACTIVE_INTERFACE=$interface
-                echo "Found interface: $interface"
-                break
-            fi
-        done
-        HTTP_SERVER_IP=$(ip a l $ACTIVE_INTERFACE | awk '/inet / {print $2}' | cut -d/ -f1)
-    elif [ "$(uname -s)" = "Darwin" ]; then
-        ACTIVE_INTERFACE="en0"
-        HTTP_SERVER_IP=$(ifconfig $ACTIVE_INTERFACE | awk '/inet / {print $2}' | cut -d/ -f1)
-    fi
     
-    if [ -z $ACTIVE_INTERFACE ]; then
-        echo "ACTIVE_INTERFACE cannot be an empty string. Please check your network configuration
-        and set an appropriate value for ACTIVE_INTERFACE"
-        exit 1
+    # Get Packer HTTP server IP from env var if set
+    PACKER_HTTP_SERVER_IP=${PACKER_HTTP_SERVER_IP:-}
+    if [ -z $PACKER_HTTP_SERVER_IP ]; then
+        # Get active network interface from env var if set
+        PACKER_ACTIVE_INTERFACE="${PACKER_ACTIVE_INTERFACE:-}"
+        if [ -z $PACKER_ACTIVE_INTERFACE ]; then
+            echo "Finding interface for Packer temporary HTTP server"
+            if [ "$(uname -s)" = "Linux" ]; then
+                INTERFACES=($(ls /sys/class/net))
+                for interface in "${INTERFACES[@]}"; do
+                    if [ "$interface" = "eth0" ] || [ "$interface" = "en0" ] || [ "$interface" = "eno1" ]; then
+                        PACKER_ACTIVE_INTERFACE=$interface
+                        echo "Found interface: $interface"
+                        break
+                    fi
+                done
+            elif [ "$(uname -s)" = "Darwin" ]; then
+                PACKER_ACTIVE_INTERFACE="en0"
+            fi
+        fi
+
+        if [ -z $PACKER_ACTIVE_INTERFACE ]; then
+            echo "PACKER_ACTIVE_INTERFACE cannot be automatically determined. Please export PACKER_ACTIVE_INTERFACE=<Current Host's primary network interface>"
+            exit 1
+        fi
+
+        if [ "$(uname -s)" = "Linux" ]; then
+            PACKER_HTTP_SERVER_IP=$(ip a l $PACKER_ACTIVE_INTERFACE | awk '/inet / {print $2}' | cut -d/ -f1)
+        elif
+            [ "$(uname -s)" = "Darwin" ]; then
+            PACKER_HTTP_SERVER_IP=$(ifconfig $PACKER_ACTIVE_INTERFACE | awk '/inet / {print $2}' | cut -d/ -f1)
+        fi
     fi
 
-    PACKER_HTTP_SERVER_IP=${PACKER_HTTP_SERVER_IP:-$HTTP_SERVER_IP}
     if [ -z $PACKER_HTTP_SERVER_IP ]; then
         echo "PACKER_HTTP_SERVER_IP cannot be automatically determined.  Please export PACKER_HTTP_SERVER_IP=<Current Host's IP>"
         exit 1