Avoid stdout on all provisioners (except main)

[msaggiorato]

This is an attempt to fix #2173 and also clarify a bit of the process to pipe data to a file.

While researching this, i noticed there's a bug in the current implementation which is kind of a pain in the ass to fix, but was not introduced by my refactor.

This basically is a concurrency issue with tee. The way it currently works is that each output (stdout and stderr) are piped to FIFO queues, which is later fed to tee. The script only waits for the queue to be written, but not until tee finishes writing (appending actually) to the file. This is the reason that in some cases the log lines might be out of order, or in a weird situation. Link to an explanation of this here.

I've tried addressing this, but didn't have time to fully fix this, and I think this may be a bit out of the scope of the issue i'm trying to fix (yet it's an issue with the tee piping technique implemented)

After research, the code before my refactor behaved the same as it did before this PR. This PR effectively behaves like @tomjn suggested it should.

[update-docs]

Thanks for opening this pull request! Make sure CHANGELOG.md gets updated with this change, additionally any docs that need updated can be found at https://github.com/Varying-Vagrant-Vagrants/varyingvagrantvagrants.org

GitHub

Varying-Vagrant-Vagrants/varyingvagrantvagrants.org

The VVV docs and website. Contribute to Varying-Vagrant-Vagrants/varyingvagrantvagrants.org development by creating an account on GitHub.

[tomjn]

I'll test this later today, do you have any links for research on the tee issue?

[msaggiorato]

Added link to the PR description.

[Mte90]

FOr me it is working (tested)