Support DVC push of locked files

[prihoda]

Hi guys, it would come in handy to push locked files, e.g. using -l, --with-locked option. For example, I have many locked callback stages that download a file from a URL and I also want to have these in the remote cache.

[efiop]

Just to clarify, do you lock it somewhere down the pipeline? Or do you lock the downloader stage itself? E.g. do you do lock data.dvc or output.dvc in the example below?

dvc run -o data wget https://example.com/data
dvc run -d data -o output mycmd

The difference is that if you lock data.dvc, then push/pull/status should account for data already(unless we have a bug), and if you lock output.dvc, then only output is taken into account and data is left behind.

[efiop]

In any case, currently when we collect used cache, we only do that for stages that are not dependencies of locked stages(a so called active DAG). We need to introduce -l|--with-locked option for status/fetch/push/pull, that is going to set active=False parameter for the _used_cache function. We will implement it shortly. Thank you for the amazing feedback, as always. 🙂

[prihoda]

Oh I see! I read the warning wrong, it does just say its dependencies are not going to be pushed/pulled/fetched. So my usecase is already covered.

[efiop]

@prihoda How about we rename it to -l|--with-locked-deps then? 🙂

[prihoda]

Sounds good 😉

dvc push now works with locked files 🙂

[efiop]

Another approach with pull-specific locks is discussed here #2450 (comment)