Small fix: Improve error message when not providing provider key through x-embedding-api-key

[Hazel-Datastax]

What this PR does:
Small fix: Improve error message when not providing provider key through x-embedding-api-key

Which issue(s) this PR fixes:
Fixes #1250

Checklist

• Changes manually tested
• Automated Tests added/updated
• Documentation added/updated
• CLA Signed: DataStax CLA

[tatu-at-datastax]

Is override really always needed? (maybe it's just odd name for parameter and means "apiKey"?)

[tatu-at-datastax]

As long as Optional apiKeyOverride is really always needed, makes sense.
But confused about "override" part of the name -- if that's really just the key that is needed, fine, otherwise override would be optional I think.

Also come to think of that... if it's required, why would we use Optional<> at all?
Shouldn't be non-null value?

[Hazel-Datastax]

The name "override" is a legacy term. I've updated it accordingly.

I think changing Optional<String> to String might be too aggressive. All apiKey values come from getEmbeddingApiKey() in DataApiRequestInfo (

data-api/src/main/java/io/stargate/sgv2/jsonapi/api/request/DataApiRequestInfo.java

Line 54 in a9cb436

public Optional<String> getEmbeddingApiKey() {

). Instead of adding a checker in each embedding provider class, we could modify getEmbeddingApiKey() as follows:

  public String getEmbeddingApiKey() {
    if (embeddingApiKey.isEmpty()) {
      throw EMBEDDING_PROVIDER_API_KEY_MISSING.toApiException(
              "header value `%s` is missing in the request.",
              EMBEDDING_AUTHENTICATION_TOKEN_HEADER_NAME);
    }
    return embeddingApiKey.get();
  }

However, I think this change would limit the flexibility of the getEmbeddingApiKey() function, even though it is only used to pass the header value to each embedding provider class.

@tatu-at-datastax WDYT? Adding checker in each class or changing getEmbeddingApiKey()

[tatu-at-datastax]

The name "override" is a legacy term. I've updated it accordingly.

I think changing Optional<String> to String might be too aggressive. All apiKey values come from getEmbeddingApiKey() in DataApiRequestInfo (

data-api/src/main/java/io/stargate/sgv2/jsonapi/api/request/DataApiRequestInfo.java

Line 54 in a9cb436

public Optional<String> getEmbeddingApiKey() {

). Instead of adding a checker in each embedding provider class, we could modify getEmbeddingApiKey() as follows:

  public String getEmbeddingApiKey() {
    if (embeddingApiKey.isEmpty()) {
      throw EMBEDDING_PROVIDER_API_KEY_MISSING.toApiException(
              "header value `%s` is missing in the request.",
              EMBEDDING_AUTHENTICATION_TOKEN_HEADER_NAME);
    }
    return embeddingApiKey.get();
  }

However, I think this change would limit the flexibility of the getEmbeddingApiKey() function, even though it is only used to pass the header value to each embedding provider class.

@tatu-at-datastax WDYT? Adding checker in each class or changing getEmbeddingApiKey()

I like centralized validation: but you can split this in 2 -- "plain" getter that simply returns value (letting caller validate), then "getAndValidateEmbeddingApiKey()" that validates and gives error? Second method calls first to get value, then checks validity.

[vkarpov15]

LGTM 👍