Bazel存储库规则-在repository_ctx.execute中下载文件

Question

I have a java test I'm trying to sandbox which does somewhat of a complex download logic.
I'm thinking of writing a repository rule which will just start a java app using repository_ctx.execute to run this logic instead of duplicating it in skylark.

How should I get the contents of this call?
I can pass the java app a path/filename to download the file to but then I'm not sure what path to give it. I can maybe have that print the bytes to stdout and collect them via the exec_result (sounds horrible).

Answer 1

You can use repository_ctx.path("path/to/file") that returns a path to get a path relative to the generated workspace, then using path.realpath you can get a canonical name for the output.

Collecting the output of exec_result to use as a file input should work but it was never tried to my knowledge so there might be weird encoding issue happening.