TinyDNSTests.test_raise_dns_tcp fails

[mcepl]

While packaging 0.33.3 for openSUSE/Factory from the PyPI tarball I get this failure when running the test suite:

[   84s] =================================== FAILURES ===================================
[   84s] _______________________ TinyDNSTests.test_raise_dns_tcp ________________________
[   84s] 
[   84s] self = <dns.resolver.Resolver object at 0x7f188d75e2b0>, f = '/etc/resolv.conf'
[   84s] 
[   84s]     def read_resolv_conf(self, f: Any) -> None:
[   84s]         """Process *f* as a file in the /etc/resolv.conf format.  If f is
[   84s]         a ``str``, it is used as the name of the file to open; otherwise it
[   84s]         is treated as the file itself.
[   84s]     
[   84s]         Interprets the following items:
[   84s]     
[   84s]         - nameserver - name server IP address
[   84s]     
[   84s]         - domain - local domain name
[   84s]     
[   84s]         - search - search list for host-name lookup
[   84s]     
[   84s]         - options - supported options are rotate, timeout, edns0, and ndots
[   84s]     
[   84s]         """
[   84s]     
[   84s]         if isinstance(f, str):
[   84s]             try:
[   84s] >               cm: contextlib.AbstractContextManager = open(f)
[   84s] E               FileNotFoundError: [Errno 2] No such file or directory: '/etc/resolv.conf'
[   84s] 
[   84s] /usr/lib/python3.9/site-packages/dns/resolver.py:908: FileNotFoundError
[   84s] 
[   84s] During handling of the above exception, another exception occurred:
[   84s] 
[   84s] self = <tests.greendns_test.TinyDNSTests testMethod=test_raise_dns_tcp>
[   84s] 
[   84s]     def test_raise_dns_tcp(self):
[   84s]         # https://github.com/eventlet/eventlet/issues/499
[   84s]         # None means we don't want the server to find the IP
[   84s]         with tests.dns_tcp_server(None) as dnsaddr:
[   84s] >           resolver = Resolver()
[   84s] 
[   84s] tests/greendns_test.py:891: 
[   84s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
[   84s] /usr/lib/python3.9/site-packages/dns/resolver.py:861: in __init__
[   84s]     self.read_resolv_conf(filename)
[   84s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
[   84s] 
[   84s] self = <dns.resolver.Resolver object at 0x7f188d75e2b0>, f = '/etc/resolv.conf'
[   84s] 
[   84s]     def read_resolv_conf(self, f: Any) -> None:
[   84s]         """Process *f* as a file in the /etc/resolv.conf format.  If f is
[   84s]         a ``str``, it is used as the name of the file to open; otherwise it
[   84s]         is treated as the file itself.
[   84s]     
[   84s]         Interprets the following items:
[   84s]     
[   84s]         - nameserver - name server IP address
[   84s]     
[   84s]         - domain - local domain name
[   84s]     
[   84s]         - search - search list for host-name lookup
[   84s]     
[   84s]         - options - supported options are rotate, timeout, edns0, and ndots
[   84s]     
[   84s]         """
[   84s]     
[   84s]         if isinstance(f, str):
[   84s]             try:
[   84s]                 cm: contextlib.AbstractContextManager = open(f)
[   84s]             except OSError:
[   84s]                 # /etc/resolv.conf doesn't exist, can't be read, etc.
[   84s] >               raise NoResolverConfiguration(f"cannot open {f}")
[   84s] E               dns.resolver.NoResolverConfiguration: cannot open /etc/resolv.conf
[   84s] 
[   84s] /usr/lib/python3.9/site-packages/dns/resolver.py:911: NoResolverConfiguration
[   84s] =============================== warnings summary ===============================
[   84s] eventlet/support/greenlets.py:6
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/support/greenlets.py:6: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
[   84s]     preserves_excinfo = (distutils.version.LooseVersion(greenlet.__version__)
[   84s] 
[   84s] eventlet/support/greenlets.py:7
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/support/greenlets.py:7: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
[   84s]     >= distutils.version.LooseVersion('0.3.2'))
[   84s] 
[   84s] eventlet/debug.py:16
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/debug.py:16: DeprecationWarning: invalid escape sequence \W
[   84s]     _token_splitter = re.compile('\W+')
[   84s] 
[   84s] tests/pools_test.py:248
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/tests/pools_test.py:248: PytestCollectionWarning: cannot collect test class 'TestTookTooLong' because it has a __init__ constructor (from: tests/pools_test.py)
[   84s]     class TestTookTooLong(Exception):
[   84s] 
[   84s] eventlet/green/http/client.py:55
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/green/http/client.py:55: DeprecationWarning: invalid escape sequence \_
[   84s]     """HTTP/1.1 client library
[   84s] 
[   84s] tests/openssl_test.py::test_import
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/green/OpenSSL/crypto.py:1: DeprecationWarning: PKCS#7 support in pyOpenSSL is deprecated. You should use the APIs in cryptography.
[   84s]     from OpenSSL.crypto import *
[   84s] 
[   84s] tests/openssl_test.py::test_import
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/green/OpenSSL/crypto.py:1: DeprecationWarning: PKCS#12 support in pyOpenSSL is deprecated. You should use the APIs in cryptography.
[   84s]     from OpenSSL.crypto import *
[   84s] 
[   84s] tests/tpool_test.py: 1000 warnings
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/tests/tpool_test.py:322: DeprecationWarning: Please use assertTrue instead.
[   84s]     assert_(token is not None)
[   84s] 
[   84s] tests/wsgi_test.py::TestHttpd::test_disable_header_name_capitalization
[   84s]   /home/abuild/rpmbuild/BUILD/eventlet-0.33.3/eventlet/greenthread.py:221: DeprecationWarning: capitalize_response_headers is disabled.
[   84s]    Please, make sure you know what you are doing.
[   84s]    HTTP headers names are case-insensitive per RFC standard.
[   84s]    Most likely, you need to fix HTTP parsing in your client software.
[   84s]     result = function(*args, **kwargs)
[   84s] 
[   84s] -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
[   84s] =========================== short test summary info ============================
[   84s] FAILED tests/greendns_test.py::TinyDNSTests::test_raise_dns_tcp - dns.resolve...
[   84s] = 1 failed, 577 passed, 108 skipped, 20 deselected, 1008 warnings in 76.85s (0:01:16) =

This is the complete build log with all details of packages used and steps to reproduce the problem.

[radeksm]

Hi @mcepl
Just looking at the error:

dns.resolver.NoResolverConfiguration: cannot open /etc/resolv.conf

The problem doesn't seem to be related to the TinyDNSTests.test_raise_dns_tcp but rather your VM where you run that test, for whatever reason is missing /etc/resolv.conf.

IMHO, this is not a bug.