kong.service.response.get_body() doesn't work properly when using gzip about kong

[chobits]

local a=kong.service.response.get_body("application/json")kong.log.err("Logger: "..a.ref_id)

Maybe a.ref_id trigger the error because a is nil. so referring .ref_id from nil(a) table will report runtime error

[bungle]

@budiprihhastomo, @chobits, yes, this is a known issue. I think we need to fix it.

[bungle]

As a workaround you can probably use:
kong.service.response.get_raw_body() + https://github.com/Kong/kong/blob/master/kong/tools/gzip.lua#L57-L59C4

[budiprihhastomo]

Thanks for the explanation.

Maybe a.ref_id trigger the error because a is nil. so referring .ref_id from nil(a) table will report runtime error

That's right, that's the reason, but it happens because basically the contents of the body's response have not been decoded from gzip.

As a workaround you can probably use:
kong.service.response.get_raw_body() + https://github.com/Kong/kong/blob/master/kong/tools/gzip.lua#L57-L59C4

CMIIW, I've checked, but unfortunately, it looks like the gzip file is not yet in the tagging version. I only found it on the master branch.

[budiprihhastomo]

Hi, is there any follow-up regarding this issue?

[bungle]

@budiprihhastomo it has been very long here (and in older versions):
https://github.com/Kong/kong/blob/3.5.0/kong/tools/utils.lua#L1380-L1389

Also the tools.gzip is still usable through tools.utils for backward compatibility.

[budiprihhastomo]

Ah sorry I didn't see it, I thought the file matched the file name you gave earlier. Thank you @bungle for helping me.

I have tried, but there is a little problem here, how to use it correctly? When I use require, it won't work for sandbox mode reasons.

But if I use it like this:

local utils = kong.tools.utils
local rawBody = kong.service.response.get_raw_body()
local inflateGzip = utils.inflate_gzip(rawBody)
kong.log.err("RESPONSE: " .. inflateGzip)

I get a response like the following:

staging-gateway_kong.1.v4px42xqzt54@staging    | 2023/12/14 14:00:32 [error] 1265#0: *2202394 failed to run body_filter_by_lua*: /usr/local/share/lua/5.1/kong/tools/kong-lua-sandbox.lua:164: [string "local kong=kong;local a=kong.tools.utils;loca..."]:1: attempt to index field 'tools' (a nil value)

Sorry that I'm having trouble finding documentation regarding the use of the gzip utility. Thank you.

[budiprihhastomo]

It seems like you can't fully use sandbox mode, right?

I have successfully used inflate_gzip, but I need to ignore that module. Related documents are here untrusted_lua_sandbox_requires.

Thanks @bungle and @chobits for the help, I really appreciate it.
And maybe if there is a better recommendation than this, I really hope for it.