Did elasticsearch cluster name includes special characters

Did elasticsearch cluster name includes special characters. If Iam including I am getting error. Please anyone clarify on this. How can I use special characters also

I always thought that the cluster.name setting found on https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster.name.html#cluster.name
always must consist of alphanumeric characters and dash/underscore.

What characters are you trying to use?

I am using default_elastic. I am getting error

Can you share the error?

Yes. Below is the error I am getting:
The Elasticsearch "default_elastic" is invalid: metadata.name: Invalid value: "default_elastic": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is 'a-z0-9?(.a-z0-9?)*')

Are you using it on kubernetes by any chance?
It looks like that, and it is not an elastic thing but more a k8s thing.

For instance:

You can use the characters a-z or "-" or a "." but no other characters.

Yes, I am using it in kubernetes. Thank you

Looks like it is using the same name for the 'host' and node, and since they have to be DNS names, cannot use underscore. Just use dash. Annoying, I know.

Is there any way to use underscores with Capital letters for cluster name. Thanks in advance

No I do not think that it is possible, it has to follow the RFC guidelines.

okay. Thank you