Writing response body to an file, K6

Grafana k6 OSS Support
1

Hi,
I’m currently running a very basic K6 test script, and I’m able to see the response body if I use console.log().

However, it’s a very extensive load test I’m preparing and I need to save all the responses I get to a file, for future analysis.

I’ve currently tried the solutions mentioned in the following posts:

When using docker-compose run k6 run --logformat raw tests.js --console-output=./test.csv it only works on windows but not Ubuntu(Unix/linux) system.
docker-compose run -u "$(id -u):$(id -g)" k6 run --logformat raw --console-output=/scripts/test.csv /scripts/stages.js gives test.csv permission denied

I’ve also tried k6 run test.js 2>responses.csv and different file names, the output file turns out to be empty at the moment. I was logging the response as console.log() and alternatively as console.debug()
docker-compose run k6 run --logformat raw --http-debug=full tests.js 2>test.csv
Also returned an empty file.

Is there any way to be able to save the raw responses we get from a request.

Would also be helpful if we can save responses to influxdb

Trying to run this on Ubuntu

2

You don’t say anywhere if you use docker volumes, which is the easiest way to have k6 write a file to a filesystem outside of the docker container. See Volumes | Docker Documentation and https://www.baeldung.com/ops/docker-volumes#starting-a-container-with-a-volume for more details.

3

Hey Ned, thanks for getting back so quick.

I tried following:
docker-compose run -v test_output:/var/opt/project k6 run --logformat raw /scripts/ewoks.js --console-output=var/opt/internal/consoleoutput.txt

and got open /var/opt/project/consoleout.txt: permission denied

test_output is a new docker volume that I created.
also tried a local directory as bind mount, it gave permission denied

Update its working now, just needed a --user $UID tag for docker-compose
SOLVED

1 Like