feat: Auth Bearer Token Support

[ColinLeverger]

Feature request

I have deployed an OpenLLM on a managed service that is protected by the use of an auth Bearer token:

curl -X 'POST' \
  'https://themodel.url/v1/generate' \
  -H "Authorization: Bearer Sh6Kh4[ . . . super long bearer token ]W18UiWuzsz+0r+U"
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "prompt": "What is the difference between a pigeon",
  "llm_config": {
    "use[ . . . and so on]
    }
  }'

Curl works like a charm.

In LangChain, I try to create my new llm as such:

llm = OpenLLM(server_url="https://themodel.url/v1/generate", temperature=0.2)

After digging your repo, did not find any options for including the Bearer token nor to modify the headers of a distant openllm session!

Motivation

Modifying the Headers would enable the use of self deployed LLM without any auth proxy

Other

No response

[aarnphm]

This is now supported with #605, you can export the envvar with OPENLLM_AUTH_TOKEN