Delete ooni_home_autorun on hard reset

[majakomel]

Closes ooni/probe#2071

Do we also need to stop autorun at this point?

[hellais]

I think that what we ought to be doing is calling ooniprobe reset --force with the OONI_HOME environment variable set to getAutorunHomeDir.

That way, if there is any additional cleanup operation that needs to happen on hard reset, we can implement it inside of probe-cli directly and not have to remember to keep it in sync between the two directories.

[hellais]

Do we also need to stop autorun at this point?

I don't think we should do that. The autorun home directory will be re-created automatically the next time it runs, but it will be empty.

I guess one thing we need to think about is what is going to happen if the hard reset is executed while the autorun task is currently running.

[bassosimone]

@hellais wrote:

I guess one thing we need to think about is what is going to happen if the hard reset is executed while the autorun task is currently running.

Yeah, this would be an interesting scenario

[bassosimone]

The diff looks good to me. I have spent some time thinking about what could happen if a hard reset occurs while an autorun is running, and I don't know what could happen. 🤷

[hellais]

I guess the database write operations are going to fail when they are attempted.

I tried to reproduce this by running ooniprobe and deleting the home directory while it's running and got this:

   ⨯ Failed to create the network row error=unable to open database file: no such file or directory
[engine] sessionresolver: failure rate: primary: 0/3; fallback: 0/0
   ⨯ failed to run circumvention error=unable to open database file: no such file or directory

On the second run it worked fine, so I guess it's not so tragic that the running test will fail.

I think we can go ahead and merge this.