allow to override default boxes cache location

[fcrozat]

If KIWI_BOXED_CACHE_DIR environment variable is set, it will be used to store kiwi boxes used for build.

[schaefi]

@fcrozat Thanks for the PR, this looks good to me and is a nice extension to the plugin. There are two issues not directly related to the implementation.

1. shellcheck became more picky and complains about SC2317 which can be ignored for the special images.sh. I added a PR to fix this in Fix shellcheck for SC2317 #76
2. your code should be covered by a test. Please let me know when you want me to jump in for writing the test case

Thanks much

[fcrozat]

@schaefi thanks for the review. it would be much better that you write the test, I'm not used to this test framework.

[schaefi]

@schaefi thanks for the review. it would be much better that you write the test, I'm not used to this test framework.

ok, no problem :) I pushed a commit to your fork and hope this is ok

[schaefi]

@fcrozat It would be nice if you can add some words to the man page about the new variable

• kiwi-boxed-plugin/doc/source/commands/system_boxbuild.rst

Thanks much

[schaefi]

@fcrozat If you find the time it would be great to add a description of the new env var in the man page. After that feel free to rebase your fork into one commit and we can merge (or I will squash commits on merge). As you prefer. Thanks

[schaefi]

looks good, thanks for your work 👍

Once the man page gets some info on the new env var we are ready to merge. Approving in advance of this change. Thanks

[fcrozat]

@schaefi documentation done