feat(plugins): enable ai plugins to read request body from buffered file

changelog/unreleased/kong/ai-plugin-read-file.yml

@@ -0,0 +1,3 @@
+message: "allow AI plugin to read request from buffered file" 
+type: feature
+scope: "Plugin"

kong/plugins/ai-prompt-decorator/handler.lua

@@ -55,7 +55,7 @@ function plugin:access(conf)
   kong.ctx.shared.ai_prompt_decorated = true  -- future use
 
   -- if plugin ordering was altered, receive the "decorated" request
-  local request = kong.request.get_body("application/json")
+  local request = kong.request.get_body("application/json", nil, conf.max_request_body_size)
   if type(request) ~= "table"  then
     return bad_request("this LLM route only supports application/json requests")
   end

kong/plugins/ai-prompt-decorator/schema.lua

@@ -39,7 +39,9 @@ return {
     { config = {
       type = "record",
       fields = {
-          { prompts = prompts_record }
+          { prompts = prompts_record },
+          { max_request_body_size = { type = "integer", default = 8 * 1024, gt = 0,
+                                    description = "max allowed body size allowed to be introspected" } },
         }
       }
     }

kong/plugins/ai-prompt-guard/handler.lua

@@ -121,7 +121,7 @@ function plugin:access(conf)
   kong.ctx.shared.ai_prompt_guarded = true -- future use
 
   -- if plugin ordering was altered, receive the "decorated" request
-  local request = kong.request.get_body("application/json")
+  local request = kong.request.get_body("application/json", nil, conf.max_request_body_size)
   if type(request) ~= "table" then
     return bad_request("this LLM route only supports application/json requests")
   end

kong/plugins/ai-prompt-guard/schema.lua

@@ -32,6 +32,12 @@ return {
               type = "boolean",
               required = true,
               default = false } },
+          { max_request_body_size = {
+              type = "integer",
+              default = 8 * 1024,
+              gt = 0,
+              description = "max allowed body size allowed to be introspected",}
+          },
         }
       }
     }

kong/plugins/ai-prompt-template/handler.lua

@@ -64,10 +64,10 @@ function AIPromptTemplateHandler:access(conf)
   kong.ctx.shared.ai_prompt_templated = true
 
   if conf.log_original_request then
-    kong.log.set_serialize_value(LOG_ENTRY_KEYS.REQUEST_BODY, kong.request.get_raw_body())
+    kong.log.set_serialize_value(LOG_ENTRY_KEYS.REQUEST_BODY, kong.request.get_raw_body(conf.max_request_body_size))
   end
 
-  local request = kong.request.get_body("application/json")
+  local request = kong.request.get_body("application/json", nil, conf.max_request_body_size)
   if type(request) ~= "table" then
     return bad_request("this LLM route only supports application/json requests")
   end

kong/plugins/ai-prompt-template/schema.lua

@@ -45,6 +45,12 @@ return {
             required = true,
             default = false,
         }},
+        { max_request_body_size = {
+            type = "integer",
+            default = 8 * 1024,
+            gt = 0,
+            description = "max allowed body size allowed to be introspected",
+        }},
       }
     }}
   },

kong/plugins/ai-proxy/handler.lua

@@ -315,7 +315,7 @@ function _M:access(conf)
     -- first, calculate the coordinates of the request
     local content_type = kong.request.get_header("Content-Type") or "application/json"
 
-    request_table = kong.request.get_body(content_type)
+    request_table = kong.request.get_body(content_type, nil, conf.max_request_body_size)
 
     if not request_table then
       if not string.find(content_type, "multipart/form-data", nil, true) then

kong/plugins/ai-proxy/schema.lua

@@ -13,6 +13,13 @@ local ai_proxy_only_config = {
         default = "allow",
         one_of = { "allow", "deny", "always" }},
     },
+    {
+      max_request_body_size = {
+      type = "integer",
+      default = 8 * 1024,
+      gt = 0,
+      description = "max allowed body size allowed to be introspected",}
+    },
 }
 
 for i, v in pairs(ai_proxy_only_config) do

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

@@ -55,7 +55,7 @@ function _M:access(conf)
   -- if asked, introspect the request before proxying
   kong.log.debug("introspecting request with LLM")
   local new_request_body, err = ai_driver:ai_introspect_body(
-    kong.request.get_raw_body(),
+    kong.request.get_raw_body(conf.max_request_body_size),
     conf.prompt,
     http_opts,
     conf.transformation_extract_pattern

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

@@ -37,6 +37,14 @@ return {
           default = true,
         }},
 
+        {
+          max_request_body_size = {
+          type = "integer",
+          default = 8 * 1024,
+          gt = 0,
+          description = "max allowed body size allowed to be introspected",}
+        },
+
         -- from forward-proxy
         { http_proxy_host = typedefs.host },
         { http_proxy_port = typedefs.port },
@@ -46,7 +54,7 @@ return {
         { llm = llm.config_schema },
       },
     }},
-    
+
   },
   entity_checks = {
     {

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

@@ -113,7 +113,9 @@ function _M:access(conf)
 
   kong.log.debug("intercepting plugin flow with one-shot request")
   local httpc = http.new()
-  local res, err = subrequest(httpc, kong.request.get_raw_body(), http_opts)
+  local res, err = subrequest(httpc,
+    kong.request.get_raw_body(conf.max_request_body_size),
+    http_opts)
   if err then
     return internal_server_error(err)
   end

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

@@ -46,6 +46,13 @@ return {
             default = true,
         }},
 
+        { max_request_body_size = {
+            type = "integer",
+            default = 8 * 1024,
+            gt = 0,
+            description = "max allowed body size allowed to be introspected",}
+        },
+
         -- from forward-proxy
         { http_proxy_host = typedefs.host },
         { http_proxy_port = typedefs.port },