How can I refer to the generated domain name of `elasticsearch.CfnDomain` in AWS CDK?

Question

I created a CfnDomain in AWS CDK and I was trying to get the generated domain name to create an alarm.

const es = new elasticsearch.CfnDomain(this, id, esProps);

new cloudwatch.CfnAlarm(this, "test", {
  ...
  dimensions: [
    {
      name: "DomainName",
      value: es.domainName,
    },
  ],
});

But it seems that the domainName attribute is actually the argument that I pass in (I passed none so it will be autogenerated), so it's actually undefined and can't be used.

Is there any way that I can specify it such that it will wait for the elasticsearch cluster to be created so that I can obtain the generated domain name, or is there any other way to created an alarm for the metrics of the cluster?

Answer 1

You use CfnDomain.ref as the domain value for your dimension. Sample alarm creation for red cluster status:

const domain: CfnDomain = ...;
const elasticDimension = {
    "DomainName": domain.ref,
};

const metricRed = new Metric({
    namespace: "AWS/ES",
    metricName: "ClusterStatus.red",
    statistic: "maximum",
    period: Duration.minutes(1),
    dimensions: elasticDimension
});

const redAlarm = metricRed.createAlarm(construct, "esRedAlarm", {
    alarmName: "esRedAlarm",
    evaluationPeriods: 1,
    threshold: 1
});