Import fails if `HOME` not set

[rmwoods]

In cases where HOME is not set (e.g. in our case, when btrdb is imported in a webapp controlled by supervisorctl), importing btrdb fails at utils/credentials.py:30

CREDENTIALS_PATH = os.path.join(os.environ["HOME"], CONFIG_DIR, CREDENTIALS_FILENAME)

This can be reproduced as follows:

# bash
unset HOME

then

# in python
import btrdb

Which produces:

In [1]: import btrdb                                                                                                                                                   
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-1-36165869e3ee> in <module>
----> 1 import btrdb

~/Preteckt/tools/preteckt_dash/env/lib/python3.6/site-packages/btrdb/__init__.py in <module>
     20 from btrdb.exceptions import ConnectionError
     21 from btrdb.version import get_version
---> 22 from btrdb.utils.credentials import credentials_by_profile, credentials
     23 from btrdb.stream import MINIMUM_TIME, MAXIMUM_TIME
     24 

~/Preteckt/tools/preteckt_dash/env/lib/python3.6/site-packages/btrdb/utils/credentials.py in <module>
     28 CONFIG_DIR = ".predictivegrid"
     29 CREDENTIALS_FILENAME = "credentials.yaml"
---> 30 CREDENTIALS_PATH = os.path.join(os.environ["HOME"], CONFIG_DIR, CREDENTIALS_FILENAME)
     31 
     32 ##########################################################################

/usr/lib/python3.6/os.py in __getitem__(self, key)
    667         except KeyError:
    668             # raise KeyError with the original key value
--> 669             raise KeyError(key) from None
    670         return self.decodevalue(value)
    671 

KeyError: 'HOME'

There is of course a workaround to set the HOME var by hand, but it seems like this shouldn't be a requirement.

[looselycoupled]

Hi @rmwoods, a new PR (#74 ) was recently merged to address this. We're now using os.path.expanduser("~") which is safer to use. If the user does not have a home directory then root is returned instead of raising an exception according to our tests.

The test here is for a credentials file which is not a documented feature and the code path will not be a problem if you are supplying address and API key through ENV or by passing as arguments.

[rmwoods]

@looselycoupled Seems to be working now - thanks for the quick fix!

[rmwoods]

Addressed by PR 74.