fix(ai-proxy): cloud identity (sdk) now used in ai transformer plugins

changelog/unreleased/kong/ai-proxy-cloud-identity-transformer-plugins.yml

@@ -0,0 +1,5 @@
+message: |
+  **AI-Transformer-Plugins**: Fixed a bug where cloud identity authentication 
+  was not used in `ai-request-transformer` and `ai-response-transformer` plugins.
+scope: Plugin
+type: bugfix

kong/llm/drivers/azure.lua

@@ -40,7 +40,7 @@ function _M.post_request(conf)
   end
 end
 
-function _M.subrequest(body, conf, http_opts, return_res_table)
+function _M.subrequest(body, conf, http_opts, return_res_table, identity_interface)
   local body_string, err
 
   if type(body) == "table" then

kong/llm/drivers/bedrock.lua

@@ -306,7 +306,7 @@ function _M.to_format(request_table, model_info, route_type)
   return response_object, content_type, nil
 end
 
-function _M.subrequest(body, conf, http_opts, return_res_table)
+function _M.subrequest(body, conf, http_opts, return_res_table, identity_interface)
   -- use shared/standard subrequest routine
   local body_string, err
 
@@ -322,25 +322,52 @@ function _M.subrequest(body, conf, http_opts, return_res_table)
   end
 
   -- may be overridden
-  local url = (conf.model.options and conf.model.options.upstream_url)
-    or fmt(
-    "%s%s",
-    ai_shared.upstream_url_format[DRIVER_NAME],
-    ai_shared.operation_map[DRIVER_NAME][conf.route_type].path
-  )
+  local f_url = conf.model.options and conf.model.options.upstream_url
+
+  if not f_url then  -- upstream_url override is not set
+    local uri = fmt(ai_shared.upstream_url_format[DRIVER_NAME], identity_interface.interface.config.region)
+    local path = fmt(
+      ai_shared.operation_map[DRIVER_NAME][conf.route_type].path,
+      conf.model.name,
+      "converse")
 
-  local method = ai_shared.operation_map[DRIVER_NAME][conf.route_type].method
+    f_url = fmt("%s%s", uri, path)
+  end
+
+  local parsed_url = socket_url.parse(f_url)
+  local method = ai_shared.operation_map[DRIVER_NAME][conf.route_type].method  
+
+  -- do the IAM auth and signature headers
+  identity_interface.interface.config.signatureVersion = "v4"
+  identity_interface.interface.config.endpointPrefix = "bedrock"
+
+  local r = {
+    headers = {},
+    method = method,
+    path = parsed_url.path,
+    host = parsed_url.host,
+    port = tonumber(parsed_url.port) or 443,
+    body = cjson.encode(body),
+  }
+
+  local signature, err = signer(identity_interface.interface.config, r)
+  if not signature then
+    return nil, "failed to sign AWS request: " .. (err or "NONE")
+  end
 
   local headers = {
     ["Accept"] = "application/json",
     ["Content-Type"] = "application/json",
   }
-
-  if conf.auth and conf.auth.header_name then
-    headers[conf.auth.header_name] = conf.auth.header_value
+  headers["Authorization"] = signature.headers["Authorization"]
+  if signature.headers["X-Amz-Security-Token"] then 
+    headers["X-Amz-Security-Token"] = signature.headers["X-Amz-Security-Token"]
+  end
+  if signature.headers["X-Amz-Date"] then
+    headers["X-Amz-Date"] = signature.headers["X-Amz-Date"]
   end
 
-  local res, err, httpc = ai_shared.http_request(url, body_string, method, headers, http_opts, return_res_table)
+  local res, err, httpc = ai_shared.http_request(f_url, body_string, method, headers, http_opts, return_res_table)
   if err then
     return nil, nil, "request to ai service failed: " .. err
   end

kong/llm/drivers/gemini.lua

@@ -262,7 +262,7 @@ function _M.to_format(request_table, model_info, route_type)
   return response_object, content_type, nil
 end
 
-function _M.subrequest(body, conf, http_opts, return_res_table)
+function _M.subrequest(body, conf, http_opts, return_res_table, identity_interface)
   -- use shared/standard subrequest routine
   local body_string, err
 
@@ -292,7 +292,24 @@ function _M.subrequest(body, conf, http_opts, return_res_table)
     ["Content-Type"] = "application/json",
   }
 
-  if conf.auth and conf.auth.header_name then
+  if identity_interface and identity_interface.interface then
+    if identity_interface.interface:needsRefresh() then
+      -- HACK: A bug in lua-resty-gcp tries to re-load the environment
+      --       variable every time, which fails in nginx
+      --       Create a whole new interface instead.
+      --       Memory leaks are mega unlikely because this should only
+      --       happen about once an hour, and the old one will be
+      --       cleaned up anyway.
+      local service_account_json = identity_interface.interface.service_account_json
+      local identity_interface_new = identity_interface.interface:new(service_account_json)
+      identity_interface.interface.token = identity_interface_new.token
+
+      kong.log.notice("gcp identity token for ", kong.plugin.get_id(), " has been refreshed")
+    end
+
+    headers["Authorization"] = "Bearer " .. identity_interface.interface.token
+
+  elseif conf.auth and conf.auth.header_name then
     headers[conf.auth.header_name] = conf.auth.header_value
   end
 

kong/llm/drivers/shared.lua

@@ -70,9 +70,6 @@ local AWS = require("resty.aws")
 local AWS_REGION do
   AWS_REGION = os.getenv("AWS_REGION") or os.getenv("AWS_DEFAULT_REGION")
 end
-
-local AZURE_TOKEN_SCOPE = "https://cognitiveservices.azure.com/.default"
-local AZURE_TOKEN_VERSION = "v2.0"
 ----
 
 _M._CONST = {

kong/llm/init.lua

@@ -95,9 +95,9 @@ do
     local ai_request
 
     -- mistral, cohere, titan (via Bedrock) don't support system commands
-    if self.driver == "bedrock" then
+    if self.conf.model.provider == "bedrock" then
       for _, p in ipairs(self.driver.bedrock_unsupported_system_role_patterns) do
-        if request.model:find(p) then
+        if self.conf.model.name:find(p) then
           ai_request = {
             messages = {
               [1] = {
@@ -147,7 +147,7 @@ do
     ai_shared.pre_request(self.conf, ai_request)
 
     -- send it to the ai service
-    local ai_response, _, err = self.driver.subrequest(ai_request, self.conf, http_opts, false)
+    local ai_response, _, err = self.driver.subrequest(ai_request, self.conf, http_opts, false, self.identity_interface)
     if err then
       return nil, "failed to introspect request with AI service: " .. err
     end
@@ -225,13 +225,15 @@ do
   --- Instantiate a new LLM driver instance.
   -- @tparam table conf Configuration table
   -- @tparam table http_opts HTTP options table
+  -- @tparam table [optional] cloud-authentication identity interface
   -- @treturn[1] table A new LLM driver instance
   -- @treturn[2] nil
   -- @treturn[2] string An error message if instantiation failed
-  function _M.new_driver(conf, http_opts)
+  function _M.new_driver(conf, http_opts, identity_interface)
     local self = {
       conf = conf or {},
       http_opts = http_opts or {},
+      identity_interface = identity_interface,  -- 'or nil'
     }
     setmetatable(self, LLM)
 

kong/plugins/ai-request-transformer/handler.lua

@@ -5,11 +5,17 @@ local kong_meta     = require "kong.meta"
 local fmt           = string.format
 local llm           = require("kong.llm")
 local llm_state     = require("kong.llm.state")
+local ai_shared     = require("kong.llm.drivers.shared")
 --
 
 _M.PRIORITY = 777
 _M.VERSION = kong_meta.version
 
+local _KEYBASTION = setmetatable({}, {
+  __mode = "k",
+  __index = ai_shared.cloud_identity_function,
+})
+
 local function bad_request(msg)
   kong.log.info(msg)
   return kong.response.exit(400, { error = { message = msg } })
@@ -40,14 +46,25 @@ local function create_http_opts(conf)
 end
 
 function _M:access(conf)
+  local kong_ctx_shared = kong.ctx.shared
+
   kong.service.request.enable_buffering()
   llm_state.should_disable_ai_proxy_response_transform()
 
+  -- get cloud identity SDK, if required
+  local identity_interface = _KEYBASTION[conf.llm]
+
+  if identity_interface and identity_interface.error then
+    kong_ctx_shared.skip_response_transformer = true
+    kong.log.err("error authenticating with ", conf.model.provider, " using native provider auth, ", identity_interface.error)
+    return kong.response.exit(500, "LLM request failed before proxying")
+  end
+
   -- first find the configured LLM interface and driver
   local http_opts = create_http_opts(conf)
   conf.llm.__plugin_id = conf.__plugin_id
   conf.llm.__key__ = conf.__key__
-  local ai_driver, err = llm.new_driver(conf.llm, http_opts)
+  local ai_driver, err = llm.new_driver(conf.llm, http_opts, identity_interface)
 
   if not ai_driver then
     return internal_server_error(err)

kong/plugins/ai-response-transformer/handler.lua

@@ -7,11 +7,17 @@ local fmt           = string.format
 local kong_utils    = require("kong.tools.gzip")
 local llm           = require("kong.llm")
 local llm_state     = require("kong.llm.state")
+local ai_shared     = require("kong.llm.drivers.shared")
 --
 
 _M.PRIORITY = 769
 _M.VERSION = kong_meta.version
 
+local _KEYBASTION = setmetatable({}, {
+  __mode = "k",
+  __index = ai_shared.cloud_identity_function,
+})
+
 local function bad_request(msg)
   kong.log.info(msg)
   return kong.response.exit(400, { error = { message = msg } })
@@ -99,14 +105,25 @@ end
 
 
 function _M:access(conf)
+  local kong_ctx_shared = kong.ctx.shared
+
   kong.service.request.enable_buffering()
   llm_state.disable_ai_proxy_response_transform()
 
+  -- get cloud identity SDK, if required
+  local identity_interface = _KEYBASTION[conf.llm]
+
+  if identity_interface and identity_interface.error then
+    kong_ctx_shared.skip_response_transformer = true
+    kong.log.err("error authenticating with ", conf.model.provider, " using native provider auth, ", identity_interface.error)
+    return kong.response.exit(500, "LLM request failed before proxying")
+  end
+
   -- first find the configured LLM interface and driver
   local http_opts = create_http_opts(conf)
   conf.llm.__plugin_id = conf.__plugin_id
   conf.llm.__key__ = conf.__key__
-  local ai_driver, err = llm.new_driver(conf.llm, http_opts)
+  local ai_driver, err = llm.new_driver(conf.llm, http_opts, identity_interface)
 
   if not ai_driver then
     return internal_server_error(err)