The /kaniko/executor --digest-file option should create parent directories

[Ark-kun]

Actual behavior
I run Kaniko Docker container with the --digest-file option:

/kaniko/executor ... --digest-file /tmp/outputs/Image_name_with_digest/data

The execution fails due to the lack of parent directories:

�[33mWARN�[0m[0055] error uploading layer to cache: writing digest to file failed: open /tmp/outputs/Image_name_with_digest/data: no such file or directory 
error pushing image: writing digest to file failed: open /tmp/outputs/Image_name_with_digest/data: no such file or directory

I cannot add a script to pre-create the parent directories, because Kaniko image is distroless and lacks sh.

Expected behavior
I expect Kaniko to create the parent directories for any output file it writes.

Description	Yes/No
Please check if this a new feature you are proposing
Please check if the build works in docker but not in kaniko
Please check if this error is seen when you use --cache flag
Please check if your dockerfile is a multistage dockerfile

[priyawadhwa]

Hey @Ark-kun thanks for opening this issue. This should be a pretty easy fix -- we can create the directories with os.MkdirAll before writing the file here.

If you, or anyone else, is interested in opening a PR, please comment here and I can assign you to the issue. Also, please cc me on any PRs opened so I can review them.

[prary]

@priyawadhwa you can assign this to me.

[priyawadhwa]

@prary sounds good!

[vivek-26]

@priyawadhwa Can I work on this issue?

[priyawadhwa]

@vivek-26 sure, looks like #884 has been quiet for a few months.

[vivek-26]

@priyawadhwa PR opened, please review.