Handle different errors and provide nice error messages

[dpordomingo]

fix #160

current sourced could fail in different ways if ~/.sourced does not exist, also some errors are not nice from the user pov.

The commits in this PR fixes:

• Make sure that ~/.sourced dir can be created when:
  • running init
  • running compose download
  • downloading 'docker-compose' script (when no installed 'docker-compose')
• Return a proper error if the user tried to run web before init
• Return a proper error if workdir.Active failed
• Return a proper error if __active__ does not exist

[se7entyse7en]

This is unnecessary.

[dpordomingo]

If removed, those errors will be wrapped by a new one, what's wrong in this case

[se7entyse7en]

Oh, you did this just to avoid wrapping, sorry. What I meant is that there's no need to fail fast here as it's already the last statement of the function.

[smacker]

yeah. it's a bit confusing

[dpordomingo]

I'll be happy if you propose a better name for this function that filters our errors

workdir.ErrMalformed
dir.ErrNotExist
dir.ErrNotDirectory

Considering it again, it might be better: isNamedError? wdyt @se7entyse7en?

The underlying problem, which is not trivial imo, is that compose.RunWithIO can fail in many ways, most of them unknown (or at least for me). And when running web command, we consider as "expected" all those unknown errors, and we just retry...
But when the error is "known" (from the list above), there is no sense to retry, and we can fail fast with a proper error message.

And I think that there is also another underlying problem: since we're bubbling errors in different places, without distinguishing them, then providing meaningful errors is a difficult task, and then we find these kinds of weird error messages from time to time.

[se7entyse7en]

you could eventually wrap also the first error an error occurred while waiting for the container to start or something along these lines.

[dpordomingo]

I think that refactors exceeds the goal of this PR.
But I pushed b5b2156 that might address your requirement about clarifying different errors that can be returned by openUI, and that will also avoid your initial —and legit— concern about

if failFast(err) {
  return err
} else {
  return error.Wrap(err)
}

[dpordomingo]

would that ☝️ be enough?

[se7entyse7en]

I'd prefer the refactor as it clearly separates the different types of errors, but it's not a big concern.

[dpordomingo]

I understand your point, and I also think that this function might be too big and with different responsibilities inside, but I do really prefer to avoid refactors when hotfixing. Thanks for being nitpicking (because it helps a lot), and also for being flexible in this case 🙇‍♂️

[dpordomingo]

you hide the reason for this error, right?

	if err := rootCmd.Run(os.Args); err != nil {
		log(err)
		os.Exit(1)
	}

how user will fix it?

@smacker nope. When command execution returns an error, it is printed automatically (I think that it's done by go-flags), so then we have:

• Causing error,
• Nice description with a high level error description.

e.g.

$ sourced status
/home/david/.sourced is not a valid config directory: it has no read-write access
Cannot perform this action, config directory is not valid

[dpordomingo]

I think that all your suggestions were already addressed, so if you agree, this should be ready for the last review from @carlosms (who he is coming back "tomorrow" Monday)

[carlosms]

Isn't this redundant? I would not print anything in this case, it does not add anything useful for the user

$ sudo mkdir /tmp/aaa
$ HOME=/tmp/aaa sourced status
mkdir /tmp/aaa/.sourced: permission denied
Unexpected error

[dpordomingo]

It was to provide homogeneous error messages, but I assume we can also remove it if it's unexpected;
Anyhow, that should not be "unexpected", will review what happened in that case.

[dpordomingo]

78f80cd fixes that @carlosms

• unknown errors will have no special message but the causing error itself,
• fixed that example, that should be as it follows:

$ HOME=/root/User sourced status
/root/User/.sourced is not a valid config directory: mkdir /root/User/.sourced: permission denied
Cannot perform this action, config directory is not valid