[BUG] `OpenSearchNodesClient#info` is unable to parse custom roles

[dennisoelkers]

What is the bug?

When a node exists in the cluster having a (custom) role which is not listed in NodeRole, executing OpenSearchClient#nodes#info fails with a JsonParsingException: Invalid enum 'customrole'.

How can one reproduce the bug?

Start a node in the cluster with a custom role.

What is the expected behavior?

OpenSearchClient#nodes#info should succeed, either stripping the custom role from the list of roles of that node, or returning a collection of strings instead of enums.

What is your host/environment?

Operating system, version.

Do you have any screenshots?

If applicable, add screenshots to help explain your problem.

Do you have any additional context?

Add any other context about the problem.

[dennisoelkers]

Btw, this also happens when the search role is added, as suggested here.

[dennisoelkers]

@dblock, @reta: Is this of any relevance for the team? This is blocking adoption of the client for us and there is no response from maintainers of the client yet. We are wondering if deprecating the previous client is a little bit premature?

[reta]

@dennisoelkers we would greatly appreciate a pull request for this issue, if you are up to it, thank you!

[dennisoelkers]

@reta: We stopped the OpenSearch client migration last year due to too many issues with the new client. We picked it up again last month, seeing that this issue has not been fixed by the team. As we understood, this is supposed to be the go-to official Java client for OpenSearch, so we are wondering why fixing issues like this has no priority?

[reta]

@reta: We stopped the OpenSearch client migration last year due to too many issues with the new client. We picked it up again last month, seeing that this issue has not been fixed by the team. As we understood, this is supposed to be the go-to official Java client for OpenSearch, so we are wondering why fixing issues like this has no priority?

@dennisoelkers the OpenSearch Java Client uses OpenAPI specification to generate the data models. The OpenAPI specification defines node roles as a set with predefined values [1] (which is mapped to Java's enumeration). To support custom roles, the OpenAPI specification needs to be updated first, and downstream components (like OpenSearch Java Client) would pick the change automatically upon new OpenAPI specification release.

[1] https://github.com/opensearch-project/opensearch-api-specification/blob/main/spec/schemas/_common.yaml#L2504