Add custom endpoint for azureADTokenProvider

[aleclair-KoAi]

Checked

• I searched existing ideas and did not find a similar one
• I added a very descriptive title
• I've clearly described the feature request and motivation for it

Feature request

I want to use azureOpenAIBasePath to get a custom endpoint which is available only with azureOpenAIApiKey, with azureADTokenProvider, url should be https://${azureOpenAIApiInstanceName}.openai.azure.com

I want to have https://${azureOpenAIApiInstanceName}.mydomain.com to use Azure API Manager (APIM)

Motivation

I am stuck with direct call instead of langchain use, it is very frustating.

Proposal (If applicable)

Some changes could be done in /openai/utils/azure.js in getEndpoint function

function getEndpoint(config) {
    const { azureOpenAIApiDeploymentName, azureOpenAIApiInstanceName, azureOpenAIApiKey, azureOpenAIBasePath, baseURL, azureADTokenProvider, } = config;
    if (azureOpenAIApiKey &&
        azureOpenAIBasePath &&
        azureOpenAIApiDeploymentName) {
        return `${azureOpenAIBasePath}/${azureOpenAIApiDeploymentName}`;
    }
    if (azureOpenAIApiKey || azureADTokenProvider) {
        if (!azureOpenAIApiInstanceName) {
            throw new Error("azureOpenAIApiInstanceName is required when using azureOpenAIApiKey");
        }
        if (!azureOpenAIApiDeploymentName) {
            throw new Error("azureOpenAIApiDeploymentName is a required parameter when using azureOpenAIApiKey");
        }
        if (azureOpenAIBasePath) {
            return `${azureOpenAIBasePath}/${azureOpenAIApiDeploymentName}`
        } else {
            return `https://${azureOpenAIApiInstanceName}.openai.azure.com/openai/deployments/${azureOpenAIApiDeploymentName}`;
        }
    }
    return baseURL;
}

[aleclair-KoAi]

done by #5521