apiVersion: v1
data:
  create_ca.sh: |
    #!/bin/bash

    set -e

    usage() {
        cat <<EOF
    Generate certificate suitable for use with an sidecar-injector webhook service.
    This script uses k8s' CertificateSigningRequest API to a generate a
    certificate signed by k8s CA suitable for use with sidecar-injector webhook
    services. This requires permissions to create and approve CSR. See
    https://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster for
    detailed explantion and additional instructions.
    The server key/cert k8s CA cert are stored in a k8s secret.
    usage: ${0} [OPTIONS]
    The following flags are required.
           --service          Service name of webhook.
           --namespace        Namespace where webhook service and secret reside.
           --secret           Secret name for CA certificate and server certificate/key pair.
    EOF
        exit 1
    }

    while [[ $# -gt 0 ]]; do
        case ${1} in
            --service)
                service="$2"
                shift
                ;;
            --secret)
                secret="$2"
                shift
                ;;
            --namespace)
                namespace="$2"
                shift
                ;;
            *)
                usage
                ;;
        esac
        shift
    done

    [ -z ${service} ] && service=$(webhookNamePrefix)service
    [ -z ${secret} ] && secret=webhook-certs
    [ -z ${namespace} ] && namespace=$(namespace)
    [ -z ${namespace} ] && namespace=default

    webhookDeploymentName=$(webhookNamePrefix)deployment
    mutatingWebhookConfigName=$(webhookNamePrefix)mutating-webhook-configuration
    echo ${service}
    echo ${namespace}
    echo ${secret}
    echo ${webhookDeploymentName}
    echo ${mutatingWebhookconfigName}
    if [ ! -x "$(command -v openssl)" ]; then
        echo "openssl not found"
        exit 1
    fi
    csrName=${service}.${namespace}
    tmpdir=$(mktemp -d)
    echo "creating certs in tmpdir ${tmpdir} "

    # x509 outputs a self signed certificate instead of certificate request, later used as self signed root CA
    openssl req -x509 -newkey rsa:2048 -keyout ${tmpdir}/self_ca.key -out ${tmpdir}/self_ca.crt -days 365 -nodes -subj /C=/ST=/L=/O=/OU=/CN=test-certificate-authority

    cat <<EOF >> ${tmpdir}/csr.conf
    [req]
    req_extensions = v3_req
    distinguished_name = req_distinguished_name
    [req_distinguished_name]
    [ v3_req ]
    basicConstraints = CA:FALSE
    keyUsage = nonRepudiation, digitalSignature, keyEncipherment
    extendedKeyUsage = serverAuth
    subjectAltName = @alt_names
    [alt_names]
    DNS.1 = ${service}
    DNS.2 = ${service}.${namespace}
    DNS.3 = ${service}.${namespace}.svc
    EOF

    openssl genrsa -out ${tmpdir}/server-key.pem 2048
    openssl req -new -key ${tmpdir}/server-key.pem -subj "/CN=${service}.${namespace}.svc" -out ${tmpdir}/server.csr -config ${tmpdir}/csr.conf

    # Self sign
    openssl x509 -req -days 365 -in ${tmpdir}/server.csr -CA ${tmpdir}/self_ca.crt -CAkey ${tmpdir}/self_ca.key -CAcreateserial -out ${tmpdir}/server-cert.pem

    # create the secret with CA cert and server cert/key
    kubectl create secret generic ${secret} \
            --from-file=key.pem=${tmpdir}/server-key.pem \
            --from-file=cert.pem=${tmpdir}/server-cert.pem \
            --dry-run -o yaml |
        kubectl -n ${namespace} apply -f -

    # Webhook pod needs to be restarted so that the service reload the secret
    # http://github.com/kueflow/kubeflow/issues/3227
    webhookPod=$(kubectl get pods -n ${namespace} |grep ${webhookDeploymentName} |awk '{print $1;}')
    # ignore error if webhook pod does not exist
    kubectl delete pod ${webhookPod} 2>/dev/null || true
    echo "webhook ${webhookPod} is restarted to utilize the new secret"
    
    cat ${tmpdir}/self_ca.crt
    
    # -a means base64 encode
    caBundle=$(cat ${tmpdir}/self_ca.crt | openssl enc -a -A)
    echo ${caBundle}

    patchString='[{"op": "replace", "path": "/webhooks/0/clientConfig/caBundle", "value":"{{CA_BUNDLE}}"}]'
    patchString=$(echo ${patchString} | sed "s|{{CA_BUNDLE}}|${caBundle}|g")
    echo ${patchString}

    checkWebhookConfig() {
      currentBundle=$(kubectl get mutatingwebhookconfigurations -n ${namespace} ${mutatingWebhookConfigName} -o jsonpath='{.webhooks[0].clientConfig.caBundle}')
      [[ "$currentBundle" == "$caBundle" ]]
    }

    while true; do
      if ! checkWebhookConfig; then
        echo "patching ca bundle for webhook configuration..."
        kubectl patch mutatingwebhookconfiguration ${mutatingWebhookConfigName} \
            --type='json' -p="${patchString}"
      fi
      sleep 10
    done
kind: ConfigMap
metadata:
  name: config-map
