Dvc: gs: catch and wrap exceptions

[dmpetrov]

$ dvc -V
0.60.1+39104a

$ dvc get https://github.com/vkoriukina/pretrained-models.pytorch/ --rev dvc_support model_weights/resnet50-19c8e357.pth
Adding '../../../../private/var/folders/hq/h82mgrhx37nc89_1rcg6gm280000gn/T/tmpccebo54zdvc-repo/.dvc/tmp' to '../../../../private/var/folders/hq/h82mgrhx37nc89_1rcg6gm280000gn/T/tmpccebo54zdvc-repo/.dvc/.gitignore'.
ERROR: unexpected error - 403 GET https://www.googleapis.com/storage/v1/b/vkoriukina_bucket/o?projection=noAcl&prefix=9e%2F9c86b324d80e65229fab49b8d9a8e8: [email protected] does not have storage.objects.list access to vkoriukina_bucket.

I do not have permissons to GCS bucket. The second error is legit. While the first one contains not user friendly temporary paths like ../../../../private/var/folders/hq/h82mgrhx37nc89_1rcg6gm280000gn/T/tmpccebo54zdvc-repo/.dvc/tmp

[efiop]

First step research where that exc is comming from. Then wrap the exception into something more helpful. Not sure about first Adding message just yet.

[dmpetrov]

After I fixed the permission issue:

$ dvc get https://github.com/vkoriukina/pretrained-models.pytorch/ --rev dvc_support model_weights/resnet50-19c8e357.pth
Adding '../../../../private/var/folders/hq/h82mgrhx37nc89_1rcg6gm280000gn/T/tmp1crq1jj_dvc-repo/.dvc/tmp' to '../../../../private/var/folders/hq/h82mgrhx37nc89_1rcg6gm280000gn/T/tmp1crq1jj_dvc-repo/.dvc/.gitignore'.
$ ll resnet50-19c8e357.pth
-rw-r--r--  1 dmitry  staff  102502400 Sep  3 16:59 resnet50-19c8e357.pth

The paths are very confusing.

[Suor]

A point on error messages. There are other HTTP error codes/messages, which we can encounter. We now only wrap 404 Not Found, for everything else we should at least show a status line - some people might not immediately recognize that 503 means Temporary Unavailable.

We might wrap 403 with our own message, but simply saying 403 Forbidden might be enough .though.

[Suor]

On confusing paths. We should remove that message for tmp repos entirely.

[algomaster99]

@efiop I will take this issue after exams :)

[efiop]

@algomaster99 Maybe someone else would want to take it earlier, you could pick something new then :slightly_smiling_face:

[efiop]

The first message no longer shows up, as we've removed it in another patch. @Suor The original 403 issue has a legit error in it, so it is useful as is. Would be nice to catch gs exceptions and re-raise them as a cause in DvcException though, but that is for the next iteration. Repurposing the ticket...