ngx-lua POST request body limit?

colin.macrae · 2018-05-30T22:11:01+00:00

what issues are you facing?it builds cleanly for me.these are some install notes i made a few years ago; they should work with the current versions of each s...

ngx-lua POST request body limit?

colin.macrae

Quick summary: I have a webpage with a single text area form input and submit button. When a user hits submit, the form is sent as a POST, with data in the request body. This string is then parsed, and submitted as a key-value pair to the redis cache backend. This is to store from-to URL redirects. This works fine with 50 lines, (100 URLs), but anything more than 100 lines (200 URLs) there is no data sent, and I am seeing a nil value.

The numbers I've stated I'm sure are arbitrary, but is this a known limit? I don't see anything in the logs from nginx regarding body_size too large, and I have tried various ways of increasing this apparent limit without any change in behaviour. The strannge thing is I can't find any errors.

I'm using this:

ngx.req.read_body()
local data = ngx.req.get_body_data()
if data ~= nil then
  -- do something here
else
    ngx.say("Body too large...for some reason.")
end

And seeing the "Body too large..." issue.

Any insight into this would be greatly appreciated.

Rgds,

Colin

jim.robinson

Check if it's in the body file, which is used when nginx decided it will be more efficient to use a temp file. As an example:

-- if the body is in memory record it as request.body,

-- otherwise if it is stored in a file record it as

-- request.body_file.

ngx.req.read_body()

request.body = ngx.req.get_body_data()

if not request.body then

local file = ngx.req.get_body_file()

if file then

request.body_file = file

end

...

-- if a body_file exists, ready it into memory

if request.body_file then

local fh, err = io.open(request.body_file, "rb")

if err then

ngx.status = ngx.HTTP_INTERNAL_SERVER_ERROR

ngx.log(ngx.ERR, "error reading request.body_file:", err)

return

end

request.body = fh:read("*all")

fh:close()

end

On Wednesday, May 30, 2018 at 7:11:01 AM UTC-7, Colin MacRae wrote:

Quick summary: I have a webpage with a single text area form input and submit button. When a user hits submit, the form is sent as a POST, with data in the request body. This string is then parsed, and submitted as a key-value pair to the redis cache backend. This is to store from-to URL redirects. This works fine with 50 lines, (100 URLs), but anything more than 100 lines (200 URLs) there is no data sent, and I am seeing a nil value.

The numbers I've stated I'm sure are arbitrary, but is this a known limit? I don't see anything in the logs from nginx regarding body_size too large, and I have tried various ways of increasing this apparent limit without any change in behaviour. The strannge thing is I can't find any errors.

I'm using this:

ngx.req.read_body() local data = ngx.req.get_body_data() if data ~= nil then -- do something here else ngx.say("Body too large...for some reason.") end
And seeing the "Body too large..." issue.

Any insight into this would be greatly appreciated.

Rgds,
Colin

colin.macrae

I had no idea nginx did that! Jim, you are my hero! Thanks!

I had been scratching my head over this for some time

Colin

On Wednesday, 30 May 2018 15:11:01 UTC+1, Colin MacRae wrote:

Quick summary: I have a webpage with a single text area form input and submit button. When a user hits submit, the form is sent as a POST, with data in the request body. This string is then parsed, and submitted as a key-value pair to the redis cache backend. This is to store from-to URL redirects. This works fine with 50 lines, (100 URLs), but anything more than 100 lines (200 URLs) there is no data sent, and I am seeing a nil value.

The numbers I've stated I'm sure are arbitrary, but is this a known limit? I don't see anything in the logs from nginx regarding body_size too large, and I have tried various ways of increasing this apparent limit without any change in behaviour. The strannge thing is I can't find any errors.

I'm using this:

ngx.req.read_body() local data = ngx.req.get_body_data() if data ~= nil then -- do something here else ngx.say("Body too large...for some reason.") end
And seeing the "Body too large..." issue.

Any insight into this would be greatly appreciated.

Rgds,
Colin