From 5dcd9183cb8e4473cbee68e30637ca75ccca23d7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20Luk=C5=A1a?= <marko.luksa@gmail.com>
Date: Wed, 26 Feb 2020 15:01:42 +0100
Subject: [PATCH] Perform preemption check only when used as a chained plugin

When Istio CNI is not used as a chained plugin, throwing an
error or logging the preemption warning doesn't make sense.
For example, when using Multus CNI, multiple CNI config
files are in the same dir, but none of them has precedence
over the others, as they are loaded by name. In that case,
logging the warning isn't appropriate.
---
 .../kubernetes/install/scripts/install-cni.sh | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/deployments/kubernetes/install/scripts/install-cni.sh b/deployments/kubernetes/install/scripts/install-cni.sh
index 3c55f2271..0c4099878 100755
--- a/deployments/kubernetes/install/scripts/install-cni.sh
+++ b/deployments/kubernetes/install/scripts/install-cni.sh
@@ -64,15 +64,17 @@ function find_cni_conf_file() {
 }
 
 function check_install() {
-  cfgfile_nm=$(find_cni_conf_file)
-  if [ "${cfgfile_nm}" != "${CNI_CONF_NAME}" ]; then
-    if [ -n "${CNI_CONF_NAME_OVERRIDE}" ]; then
-       # Install was run with overridden cni config file so don't error out on the preempt check.
-       # Likely the only use for this is testing this script.
-       echo "WARNING: Configured CNI config file \"${MOUNTED_CNI_NET_DIR}/${CNI_CONF_NAME}\" preempted by \"$cfgfile_nm\"."
-    else
-       echo "ERROR: CNI config file \"${MOUNTED_CNI_NET_DIR}/${CNI_CONF_NAME}\" preempted by \"$cfgfile_nm\"."
-       exit 1
+  if [ "${CHAINED_CNI_PLUGIN}" == "true" ]; then
+    cfgfile_nm=$(find_cni_conf_file)
+    if [ "${cfgfile_nm}" != "${CNI_CONF_NAME}" ]; then
+      if [ -n "${CNI_CONF_NAME_OVERRIDE}" ]; then
+         # Install was run with overridden cni config file so don't error out on the preempt check.
+         # Likely the only use for this is testing this script.
+         echo "WARNING: Configured CNI config file \"${MOUNTED_CNI_NET_DIR}/${CNI_CONF_NAME}\" preempted by \"$cfgfile_nm\"."
+      else
+         echo "ERROR: CNI config file \"${MOUNTED_CNI_NET_DIR}/${CNI_CONF_NAME}\" preempted by \"$cfgfile_nm\"."
+         exit 1
+      fi
     fi
   fi
   if [ -e "${MOUNTED_CNI_NET_DIR}/${CNI_CONF_NAME}" ]; then