rbac: adds a script to help users to upgrade to ClusterRbacConfig. (i…

…stio#9175)

* rbac: adds a script to help users to upgrade to ClusterRbacConfig.

* fix shellcheck

* resolve comments

tools/convert_RbacConfig_to_ClusterRbacConfig.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+set -e
+set -u
+
+# This script is provided to help converting RbacConfig to ClusterRbacConfig automatically. The RbacConfig
+# will be deleted after the corresponding ClusterRbacConfig is successfully applied.
+# The RbacConfig is deprecated by ClusterRbacConfig due to an implementation bug that could cause the
+# RbacConfig to be namespace scoped in some cases. The ClusterRbacConfig has exactly same specification
+# as the RbacConfig, but with correctly implemented cluster scope.
+
+RBAC_CONFIGS=$(kubectl get RbacConfig --all-namespaces --no-headers --ignore-not-found)
+if [ "${RBAC_CONFIGS}" == "" ]
+then
+  echo "RbacConfig not found"
+  exit 0
+fi
+
+RBAC_CONFIG_COUNT=$(echo "${RBAC_CONFIGS}" | wc -l)
+if [ "${RBAC_CONFIG_COUNT}" -ne 1 ]
+then
+  echo "${RBAC_CONFIGS}"
+  echo "found ${RBAC_CONFIG_COUNT} RbacConfigs, expecting only 1. Please delete extra RbacConfigs and execute again."
+  exit 1
+fi
+
+NS=$(echo "${RBAC_CONFIGS}" | cut -f 1 -d ' ')
+echo "converting RbacConfig in namespace $NS to ClusterRbacConfig"
+
+SPEC=$(kubectl get RbacConfig default -n "${NS}" -o yaml | sed -n -e '/spec:/,$p')
+
+cat <<EOF | kubectl apply -n "${NS}" -f -
+apiVersion: "rbac.istio.io/v1alpha1"
+kind: ClusterRbacConfig
+metadata:
+  name: default
+${SPEC}
+EOF
+
+# shellcheck disable=SC2181
+if [ $? -ne 0 ]
+then
+  echo "failed to apply ClusterRbacConfig"
+  exit 1
+fi
+
+echo "waiting for 15 seconds to delete RbacConfig"
+sleep 15
+kubectl delete RbacConfig --all -n "${NS}"