Avoid new dependencies that will likely break installs

See this explanation:
Supervisor#1578 (comment)

Author: mnaberez

CHANGES.rst

@@ -1,15 +1,8 @@
 4.3.0.dev0 (Next Release)
 -------------------------
 
-- The installation requirements have changed because Setuptools 67.5.0
-  deprecated the use of ``pkg_resources``, which Supervisor used to load
-  its plugins.  The ``setuptools`` package is no longer a runtime dependency
-  of Supervisor.  On Python < 3.8 where ``importlib.metadata`` is not 
-  available in stdlib, Supervisor now requires the PyPI package
-  ``importlib-metadata``.  Additionally, on Python < 3.7 where 
-  ``importlib.resources`` is not available in stdlib, Supervisor now requires
-  the PyPI package ``importlib-resources``.  These new dependencies have been
-  added as conditional requirements in ``setup.py``.  Patch by Ofek Lev.
+- On Python 3.8 and later, ``setuptools`` is no longer a runtime
+  dependency.  Patch by Ofek Lev.
 
 - ``supervisorctl`` now reads extra files included via the ``[include]``
   section in ``supervisord.conf`` like ``supervisord`` does.  This allows

setup.py

@@ -22,12 +22,13 @@
 elif (3, 0) < py_version < (3, 4):
     raise RuntimeError('On Python 3, Supervisor requires Python 3.4 or later')
 
+# setuptools is required as a runtime dependency only on
+# Python < 3.8.  See the comments in supervisor/compat.py.
 requires = [
-    "importlib-metadata; python_version < '3.8'",
-    "importlib-resources; python_version < '3.7'",
+    "setuptools; python_version < '3.8'",
 ]
-tests_require = []
 
+tests_require = []
 testing_extras = tests_require + [
     'pytest',
     'pytest-cov',

supervisor/compat.py

@@ -150,24 +150,51 @@ def is_text_stream(stream):
 except ImportError: # pragma: no cover
     from HTMLParser import HTMLParser
 
+# Begin importlib/setuptools compatibility code
+
+# Supervisor used pkg_resources (a part of setuptools) to load package
+# resources for 15 years, until setuptools 67.5.0 (2023-03-05) deprecated
+# the use of pkg_resources.  On Python 3.8 or later, Supervisor now uses
+# importlib (part of Python 3 stdlib).  Unfortunately, on Python < 3.8,
+# Supervisor needs to use pkg_resources despite its deprecation.  The PyPI
+# backport packages "importlib-resources" and "importlib-metadata" couldn't
+# be added as dependencies to Supervisor because they require even more
+# dependencies that would likely cause some Supervisor installs to fail.
+from warnings import filterwarnings as _fw
+_fw("ignore", message="pkg_resources is deprecated as an API")
+
 try: # pragma: no cover
-    import importlib.metadata as importlib_metadata
+    from importlib.metadata import EntryPoint as _EntryPoint
+
+    def import_spec(spec):
+        return _EntryPoint(None, spec, None).load()
+
 except ImportError: # pragma: no cover
-    # fall back to PyPI backport if not in stdlib
-    import importlib_metadata
+    from pkg_resources import EntryPoint as _EntryPoint
+
+    def import_spec(spec):
+        ep = _EntryPoint.parse("x=" + spec)
+        if hasattr(ep, 'resolve'):
+            # this is available on setuptools >= 10.2
+            return ep.resolve()
+        else:
+            # this causes a DeprecationWarning on setuptools >= 11.3
+            return ep.load(False)
 
 try: # pragma: no cover
-    import importlib.resources as importlib_resources
-except ImportError: # pragma: no cover
-    # fall back to PyPI backport if not in stdlib
-    import importlib_resources
+    import importlib.resources as _importlib_resources
 
-if hasattr(importlib_resources, "files"):
-    def resource_file(package, path): # pragma: no cover
-        return str(importlib_resources.files(package).joinpath(path))
+    if hasattr(_importlib_resources, "files"):
+        def resource_filename(package, path):
+            return str(_importlib_resources.files(package).joinpath(path))
 
-else: # pragma: no cover
-    # fall back to deprecated .path if .files is not available
-    def resource_file(package, path): # pragma: no cover
-        with importlib_resources.path(package, '__init__.py') as p:
-            return str(p.parent.joinpath(path))
+    else:
+        # fall back to deprecated .path if .files is not available
+        def resource_filename(package, path):
+            with _importlib_resources.path(package, '__init__.py') as p:
+                return str(p.parent.joinpath(path))
+
+except ImportError: # pragma: no cover
+    from pkg_resources import resource_filename
+
+# End importlib/setuptools compatibility code

supervisor/confecho.py

@@ -1,8 +1,8 @@
 import sys
 from supervisor.compat import as_string
-from supervisor.compat import resource_file
+from supervisor.compat import resource_filename
 
 
 def main(out=sys.stdout):
-    with open(resource_file(__package__, 'skel/sample.conf'), 'r') as f:
+    with open(resource_filename(__package__, 'skel/sample.conf'), 'r') as f:
         out.write(as_string(f.read()))

supervisor/options.py

@@ -21,7 +21,7 @@
 from supervisor.compat import xmlrpclib
 from supervisor.compat import StringIO
 from supervisor.compat import basestring
-from supervisor.compat import importlib_metadata
+from supervisor.compat import import_spec
 
 from supervisor.medusa import asyncore_25 as asyncore
 
@@ -391,7 +391,7 @@ def get_plugins(self, parser, factory_key, section_prefix):
 
     def import_spec(self, spec):
         """On failure, raises either AttributeError or ImportError"""
-        return importlib_metadata.EntryPoint(None, spec, None).load()
+        return import_spec(spec)
 
     def read_include_config(self, fp, parser, expansions):
         if parser.has_section('include'):

supervisor/tests/test_end_to_end.py

@@ -5,7 +5,7 @@
 import signal
 import sys
 import unittest
-from supervisor.compat import resource_file
+from supervisor.compat import resource_filename
 from supervisor.compat import xmlrpclib
 from supervisor.xmlrpc import SupervisorTransport
 
@@ -25,7 +25,7 @@ def test_issue_291a_percent_signs_in_original_env_are_preserved(self):
         passed to the child without the percent sign being mangled."""
         key = "SUPERVISOR_TEST_1441B"
         val = "foo_%s_%_%%_%%%_%2_bar"
-        filename = resource_file(__package__, 'fixtures/issue-291a.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-291a.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         try:
             os.environ[key] = val
@@ -38,7 +38,7 @@ def test_issue_291a_percent_signs_in_original_env_are_preserved(self):
     def test_issue_550(self):
         """When an environment variable is set in the [supervisord] section,
         it should be put into the environment of the subprocess."""
-        filename = resource_file(__package__, 'fixtures/issue-550.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-550.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -54,7 +54,7 @@ def test_issue_550(self):
     def test_issue_565(self):
         """When a log file has Unicode characters in it, 'supervisorctl
         tail -f name' should still work."""
-        filename = resource_file(__package__, 'fixtures/issue-565.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-565.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -71,7 +71,7 @@ def test_issue_565(self):
     def test_issue_638(self):
         """When a process outputs something on its stdout or stderr file
         descriptor that is not valid UTF-8, supervisord should not crash."""
-        filename = resource_file(__package__, 'fixtures/issue-638.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-638.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -90,7 +90,7 @@ def test_issue_638(self):
     def test_issue_663(self):
         """When Supervisor is run on Python 3, the eventlistener protocol
         should work."""
-        filename = resource_file(__package__, 'fixtures/issue-663.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-663.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -102,7 +102,7 @@ def test_issue_664(self):
         """When a subprocess name has Unicode characters, 'supervisord'
         should not send incomplete XML-RPC responses and 'supervisorctl
         status' should work."""
-        filename = resource_file(__package__, 'fixtures/issue-664.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-664.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -121,7 +121,7 @@ def test_issue_664(self):
     def test_issue_733(self):
         """When a subprocess enters the FATAL state, a one-line eventlistener
         can be used to signal supervisord to shut down."""
-        filename = resource_file(__package__, 'fixtures/issue-733.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-733.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -130,7 +130,7 @@ def test_issue_733(self):
         supervisord.expect(pexpect.EOF)
 
     def test_issue_835(self):
-        filename = resource_file(__package__, 'fixtures/issue-835.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-835.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -146,7 +146,7 @@ def test_issue_835(self):
             transport.connection.close()
 
     def test_issue_836(self):
-        filename = resource_file(__package__, 'fixtures/issue-836.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-836.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -169,7 +169,7 @@ def test_issue_836(self):
     def test_issue_986_command_string_with_double_percent(self):
         """A percent sign can be used in a command= string without being
         expanded if it is escaped by a second percent sign."""
-        filename = resource_file(__package__, 'fixtures/issue-986.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-986.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -178,7 +178,7 @@ def test_issue_986_command_string_with_double_percent(self):
     def test_issue_1054(self):
         """When run on Python 3, the 'supervisorctl avail' command
         should work."""
-        filename = resource_file(__package__, 'fixtures/issue-1054.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1054.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -196,7 +196,7 @@ def test_issue_1170a(self):
         """When the [supervisord] section has a variable defined in
         environment=, that variable should be able to be used in an
         %(ENV_x) expansion in a [program] section."""
-        filename = resource_file(__package__, 'fixtures/issue-1170a.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1170a.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -207,7 +207,7 @@ def test_issue_1170b(self):
         environment=, and a variable by the same name is defined in
         enviroment= of a [program] section, the one in the [program]
         section should be used."""
-        filename = resource_file(__package__, 'fixtures/issue-1170b.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1170b.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -218,7 +218,7 @@ def test_issue_1170c(self):
         environment=, and a variable by the same name is defined in
         enviroment= of an [eventlistener] section, the one in the
         [eventlistener] section should be used."""
-        filename = resource_file(__package__, 'fixtures/issue-1170c.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1170c.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -229,7 +229,7 @@ def test_issue_1224(self):
         then the non-rotating logger will be used to avoid an
         IllegalSeekError in the case that the user has configured a
         non-seekable file like /dev/stdout."""
-        filename = resource_file(__package__, 'fixtures/issue-1224.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1224.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -238,7 +238,7 @@ def test_issue_1224(self):
     def test_issue_1231a(self):
         """When 'supervisorctl tail -f name' is run and the log contains
         unicode, it should not fail."""
-        filename = resource_file(__package__, 'fixtures/issue-1231a.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1231a.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -255,7 +255,7 @@ def test_issue_1231a(self):
     def test_issue_1231b(self):
         """When 'supervisorctl tail -f name' is run and the log contains
         unicode, it should not fail."""
-        filename = resource_file(__package__, 'fixtures/issue-1231b.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1231b.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -289,7 +289,7 @@ def test_issue_1231b(self):
     def test_issue_1231c(self):
         """When 'supervisorctl tail -f name' is run and the log contains
         unicode, it should not fail."""
-        filename = resource_file(__package__, 'fixtures/issue-1231c.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1231c.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -331,7 +331,7 @@ def test_issue_1298(self):
         """When the output of 'supervisorctl tail -f worker' is piped such as
         'supervisor tail -f worker | grep something', 'supervisorctl' should
         not crash."""
-        filename = resource_file(__package__, 'fixtures/issue-1298.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1298.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -365,7 +365,7 @@ def test_issue_1418_pidproxy_cmd_with_args(self):
     def test_issue_1483a_identifier_default(self):
         """When no identifier is supplied on the command line or in the config
         file, the default is used."""
-        filename = resource_file(__package__, 'fixtures/issue-1483a.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1483a.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -384,7 +384,7 @@ def test_issue_1483a_identifier_default(self):
     def test_issue_1483b_identifier_from_config_file(self):
         """When the identifier is supplied in the config file only, that
         identifier is used instead of the default."""
-        filename = resource_file(__package__, 'fixtures/issue-1483b.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1483b.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename]
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)
@@ -403,7 +403,7 @@ def test_issue_1483b_identifier_from_config_file(self):
     def test_issue_1483c_identifier_from_command_line(self):
         """When an identifier is supplied in both the config file and on the
         command line, the one from the command line is used."""
-        filename = resource_file(__package__, 'fixtures/issue-1483c.conf')
+        filename = resource_filename(__package__, 'fixtures/issue-1483c.conf')
         args = ['-m', 'supervisor.supervisord', '-c', filename, '-i', 'from_command_line']
         supervisord = pexpect.spawn(sys.executable, args, encoding='utf-8')
         self.addCleanup(supervisord.kill, signal.SIGINT)