POST request with wrk?

Question

I started to try wrk. It's very simple to use and very hard on the server, but I don't know how to perform other kind of request such as POST. In fact, I don't even know if this tool allows it. The documentation is very minimal.

Thanks

Martineau

Answer 1

This is possible now. Here is an example https://github.com/wg/wrk/blob/master/scripts/post.lua.

wrk.method = "POST"
wrk.body   = "foo=bar&baz=quux"
wrk.headers["Content-Type"] = "application/x-www-form-urlencoded"

save this in a *.lua script and pass it into your command line test with the -s flag.

Aggregate

wow! Let me check that out. I'll switch the answer to your's if I can manage to make it work. Thanks for coming back to that post. – Martineau

You sir, are a life saver ! Just what I wanted. A simple and elegant way to test my post APIs. +1 – Supraliminal

Answer 2

for those looking for a content-type "application/json" example:

wrk.method = "POST"
wrk.body = '{"firstKey": "somedata", "secondKey": "somedata"}'
wrk.headers["Content-Type"] = "application/json"

Morvin

To post json data, this formatting actually works for me: wrk.body = '{"firstKey": "somedata", "secondKey": "somedata"}' – Bareback

Answer 3

Here's an example lua script post_binary.lua for posting binary file: "Content-Type:application/octet-stream".

wrk.method = "POST"
wrk.headers["Content-Type"] = "application/octet-stream"

file = io.open("dog.jpg", "rb")
wrk.body = file:read("*a")

Then try: wrk "your_url" -s post_binary.lua --latency -t 1 -c 1 -d 30s -R 1

Indian

Just what I was looking for! – Keg

Answer 4

I'll recommend using wrk2 instead of wrk since wrk2 provides better support for concurrent requests. When content-type header is application/json then please escape the special characters like \n with \\n and all other special characters present. Not doing this will send an invalid json to the upstream API, which will waste your time debugging.

Create a file with extension lua and paste the following in it. Save it and pass it along with -s flag to wrk2 command.

wrk.method = "POST"
wrk.body = "{\"firstKey\": 'somedata', \"secondKey\": 'somedata'}"
wrk.headers["Content-Type"] = "application/json"

Also you can add multiple header as

wrk.headers["Header1"] = "Header1_Val"
wrk.headers["Header2"] = "Header2_Val"
wrk.headers["Header3"] = "Header3_Val"
wrk.headers["Header4"] = "Header4_Val"

wrk2 -t500 -c1000 -d160s -R10000 -s ~/Documents/luaTestScript.lua http://localhost:8080/test_endpoint

Tidbit