feat: check DB connectivity before import

[betodealmeida]

Before running an import with superset sync native test the DB connectivity and warn if it fails (failure could be expected, depending on the network configuration).

[cwegener]

Works nicely! Just noticed it when I updated to latest master today. Got slightly startled on first Warning but was happy that the import completed successfully!

[betodealmeida]

Works nicely! Just noticed it when I updated to latest master today. Got slightly startled on first Warning but was happy that the import completed successfully!

Nice! Yeah, I was expecting valid cases where this would fail as expected... but it really helps debugging in other cases.

[cwegener]

One thing I forgot to mention:

The WARNING Log message does include the cleartext password in the SQLAlchemy Engine URI.

I guess that would be an easy thing to fix?

[betodealmeida]

One thing I forgot to mention:

The WARNING Log message does include the cleartext password in the SQLAlchemy Engine URI.

I guess that would be an easy thing to fix?

Oh, thanks for letting me know! That's not good, I'll fix it... I thought SQLAlchemy masked the password, I think I need to explicitly convert it to a string.