Rancher fix for cert-manager failure on rancher upgrade (no matches for kind "Issuer" in version cert-manager.io/v1beta1)

rancher-upgrade-cert-manager-version.sh

#!/bin/bash
function failure { echo $@ >&2; exit 1; }

RANCHER_NAMESPACE=${RANCHER_NAMESPACE:-cattle-system}
RANCHER_RELEASE_NAME=${RANCHER_RELEASE_NAME:-rancher}

# Pre-Flight checks
echo "ok"|sed -r "s/^(ok)/yes/"|grep yes >/dev/null \
    && echo "Preflight test : sed ok" \
    || failure "Your sed does not support extended regexp, more info at https://github.com/rancher/rancher/issues/35319#issuecomment-1173825923"

# Detecting revision number
RANCHER_REVISION=$(helm list -n ${RANCHER_NAMESPACE} |grep -E "^${RANCHER_RELEASE_NAME} " | awk '{print $3}')
# Calculating secret name
SECRET_NAME=sh.helm.release.v1.${RANCHER_RELEASE_NAME}.v${RANCHER_REVISION}


# Checking if patch is needed
echo "Checking if cert-manager beta or alpha is present in the release :"
kubectl get secrets ${SECRET_NAME} -n ${RANCHER_NAMESPACE} -o json \
    | jq .data.release -r | base64 -d | base64 -d | gzip -d \
    | grep -Eo 'cert-manager.io/v1(alpha|beta)1' \
    || failure "[WARNING] No reference found to cert-manager alpha or beta, nothing to patch"

# Create temporary file to backup secret
TMP_FILE=$(mktemp)

echo "Creating backup of helm release in file : ${TMP_FILE}"
kubectl get secrets ${SECRET_NAME} -n ${RANCHER_NAMESPACE} -o yaml > ${TMP_FILE}

# Calculating patch data with cert-manager version replacement
SECRET_RELEASE_DATA=$(kubectl get secrets ${SECRET_NAME} -n ${RANCHER_NAMESPACE} -o json \
    | jq .data.release -r | base64 -d | base64 -d | gzip -d \
    | sed -r '[email protected]/v1(alpha|beta)[email protected]/v1@' \
    | gzip | base64 | base64)

# Applying patch
echo "Applying patch"
kubectl patch secret ${SECRET_NAME} -n ${RANCHER_NAMESPACE} -p='{"data":{"release":"'${SECRET_RELEASE_DATA}'"}}'

# Checking patch
kubectl get secrets ${SECRET_NAME} -n ${RANCHER_NAMESPACE} -o json \
    | jq .data.release -r | base64 -d | base64 -d | gzip -d \
    | grep -Eo 'cert-manager.io/v1(alpha|beta)1' \
    && failure "[ERROR] Patch failed, there is still some reference to cert-manager alpha or beta, please check manually"
    
echo "Patch done :)"