Arvados

One can access collections either by their portable data hash or UUID from the "by_id" directory in the keep mount. Trying to do the same for an Arvados project will fail with a "no such file or directory".

It would be nice to be able to access Arvados projects by their UUID under the keep "by_id" directory.

Implementation details:

1. The code is in arvados/services/fuse
2. The mount point configuration is initialized in arvados_fuse/command.py
3. The "by_id" directory is implemented by the MagicDirectory class in arvados_fuse/fusedir.py
4. The MagicDirectory is special, subdirectories only appear in the listing after they are first accessed
5. The MagicDirectory.__contains__ method is called to determine if a subdirectory exists (named by portable data hash or uuid) and creates on demand it if necessary
6. Currently it creates CollectionDirectory object for collections.
7. The goal of this task is to add support to MagicDirectory for accessing projects (ProjectDirectory) by uuid.

Tests are in arvados/services/fuse/tests

The simplest way to run them is using arvbox on Linux (note, won't work on Windows/MacOS so in that case you will need to use a VM).

$ arvbox start test --only services/fuse

Alternately you can set up your workstation or a VM following these instructions: https://dev.arvados.org/projects/arvados/wiki/Hacking_prerequisites (but personally I use arvbox for all my development).

The test framework starts up the API server in testing mode with a known database, so some tests rely on the API server returning known values. These test values are defined in arvados/services/api/test/fixtures. You can probably use an existing record, such as "aproject" (uuid zzzzz-j7d0g-v955i6s2oi1cbso) defined groups.yml.

As a starting point, try looking at FuseMagicTest in arvados/services/fuse/tests/test_mount.py

To run a single test:

$ arvbox start test --only services/fuse services/fuse_test=--test-suite=tests.test_mount.FuseMagicTest