In a dagster operation I want to download a file and write it to a particular file location. The code runs without errors, but the file does not appear in the location. Using a docker to deploy. Any idea why this happenes?

I don't think yielding AssetMaterializations actually writes out any data anywhere, it's pretty much just a way to emit a metadata event to track some info about an asset. I think you'll need to either manually write your file to `target_path`within that op (then yielding the asset materialization is just a nice way to show the the path in the dagit UI), or refactor to use the SDA approach with the

@asset

decorator and an IOManager that will persist your file where you want it to go

the

client.download

function should manually save it to the

target_path

what run launcher are you using?

Could the io_manager be intercepting it?

unlikely / no

dagster_docker DockerRunLauncher

so the docker run launcher runs each dagster job in a new docker container which is terminated at the end of the job run. so anything you save "locally" within the job will be saved to the container, which is killed when the job run ends. so you need to either write to a volume mount or write to a remote storage location, like S3

thx! I will try this and get back to you