Roman Rizzi 4f1a3effe0
REFACTOR: Migrate Vllm/TGI-served models to the OpenAI format. (#588)
Both endpoints provide OpenAI-compatible servers. The only difference is that Vllm doesn't support passing tools as a separate parameter. Even if the tool param is supported, it ultimately relies on the model's ability to handle native functions, which is not the case with the models we have today.

As a part of this change, we are dropping support for StableBeluga/Llama2 models. They don't have a chat_template, meaning the new API can translate them.

These changes let us remove some of our existing dialects and are a first step in our plan to support any LLM by defining them as data-driven concepts.

 I rewrote the "translate" method to use a template method and extracted the tool support strategies into its classes to simplify the code.

Finally, these changes bring support for Ollama when running in dev mode. It only works with Mistral for now, but it will change soon..
2024-05-07 10:02:16 -03:00

97 lines
2.8 KiB
Ruby

# frozen_string_literal: true
module DiscourseAi
module Completions
module Endpoints
class Vllm < Base
class << self
def can_contact?(endpoint_name, model_name)
endpoint_name == "vllm" &&
%w[mistralai/Mixtral-8x7B-Instruct-v0.1 mistralai/Mistral-7B-Instruct-v0.2].include?(
model_name,
)
end
def dependant_setting_names
%w[ai_vllm_endpoint_srv ai_vllm_endpoint]
end
def correctly_configured?(_model_name)
SiteSetting.ai_vllm_endpoint_srv.present? || SiteSetting.ai_vllm_endpoint.present?
end
def endpoint_name(model_name)
"vLLM - #{model_name}"
end
end
def normalize_model_params(model_params)
model_params = model_params.dup
# max_tokens, temperature are already supported
if model_params[:stop_sequences]
model_params[:stop] = model_params.delete(:stop_sequences)
end
model_params
end
def default_options
{ max_tokens: 2000, model: model }
end
def provider_id
AiApiAuditLog::Provider::Vllm
end
private
def model_uri
service = DiscourseAi::Utils::DnsSrv.lookup(SiteSetting.ai_vllm_endpoint_srv)
if service.present?
api_endpoint = "https://#{service.target}:#{service.port}/v1/chat/completions"
else
api_endpoint = "#{SiteSetting.ai_vllm_endpoint}/v1/chat/completions"
end
@uri ||= URI(api_endpoint)
end
def prepare_payload(prompt, model_params, _dialect)
default_options
.merge(model_params)
.merge(messages: prompt)
.tap { |payload| payload[:stream] = true if @streaming_mode }
end
def prepare_request(payload)
headers = { "Referer" => Discourse.base_url, "Content-Type" => "application/json" }
headers["X-API-KEY"] = SiteSetting.ai_vllm_api_key if SiteSetting.ai_vllm_api_key.present?
Net::HTTP::Post.new(model_uri, headers).tap { |r| r.body = payload }
end
def partials_from(decoded_chunk)
decoded_chunk
.split("\n")
.map do |line|
data = line.split("data: ", 2)[1]
data == "[DONE]" ? nil : data
end
.compact
end
def extract_completion_from(response_raw)
parsed = JSON.parse(response_raw, symbolize_names: true).dig(:choices, 0)
# half a line sent here
return if !parsed
response_h = @streaming_mode ? parsed.dig(:delta) : parsed.dig(:message)
response_h.dig(:content)
end
end
end
end
end