fix(backend): Cache Deployer - Fixed grep call (#4568)

backend/src/cache/deployer/deploy-cache-service.sh

@@ -20,6 +20,8 @@
 
 set -ex
 
+# Warning: grep in this image does not support long option names like --word-regexp
+
 echo "Start deploying cache service to existing cluster:"
 
 NAMESPACE=${NAMESPACE_TO_WATCH:-kubeflow}
@@ -72,7 +74,7 @@ echo "Signed certificate generated for cache server"
 # Kubernetes v1.15+ supports better filtering, but it's not trivial to detect since the API version was only bumped to v1 in v1.16.
 # Kubernetes has broken it's versioning policy here. https://github.com/kubernetes/kubernetes/pull/78505#commitcomment-41870735
 # We still want to support filtering on v1.15, so we need to detect it.
-if kubectl api-versions | grep --word-regexp 'admissionregistration.k8s.io/v1'; then
+if kubectl api-versions | grep -w 'admissionregistration.k8s.io/v1'; then
     cache_webhook_config_template="cache-webhook-config.v1.yaml.template"
 elif kubectl version | grep 'Server Version: version.Info{Major:"1", Minor:"15'; then
     cache_webhook_config_template="cache-webhook-config.v1beta1.v1.15.yaml.template"