config: resolve real paths from symlinks, add paths debug logging

Tweak test expectations to include the new debug logging

Change-Id: I11a905b2467cda691d9ccea30ae436bac96476c9

selftest/resource_test.ok

@@ -9,6 +9,12 @@ The requested resource requirements are not solvable [[0, 2], [2], [0, 2]]
 ok, caused exception: RuntimeError('Refusing to drop a list of resources from itself. This is probably a bug where a list of Resources() should have been copied but is passed as-is. use Resources.clear() instead.',)
 - test removing a Resources list from one with the same list in it
 - test resources config and state dir:
+cnf -: DBG: Found config file paths.conf as [PATH]/selftest/conf/paths.conf in ./conf which is [PATH]/selftest/conf
+cnf -: DBG: [PATH]/selftest/conf/paths.conf: relative path ./suite_test is [PATH]/selftest/conf/suite_test
+cnf -: DBG: [PATH]/selftest/conf/paths.conf: relative path ./test_work/state_dir is [PATH]/selftest/conf/test_work/state_dir
+cnf -: DBG: Found path state_dir as [PATH]/selftest/conf/test_work/state_dir
+cnf -: DBG: Found config file resources.conf as [PATH]/selftest/conf/resources.conf in ./conf which is [PATH]/selftest/conf
+cnf -: DBG: Found path state_dir as [PATH]/selftest/conf/test_work/state_dir
 *** all resources:
 {'arfcn': [{'_hash': 'e620569450f8259b3f0212ec19c285dd07df063c',
             'arfcn': '512',

selftest/resource_test.ok.ign

@@ -0,0 +1 @@
+/[^ ]*/selftest/	[PATH]/selftest/

selftest/suite_test.ok

@@ -1,9 +1,15 @@
 - non-existing suite dir
---- -: ERR: RuntimeError: Suite not found: 'does_not_exist' in ./suite_test/.
+cnf -: DBG: Found config file paths.conf as [PATH]/selftest/suite_test/paths.conf in ./suite_test which is [PATH]/selftest/suite_test
+cnf -: DBG: [PATH]/selftest/suite_test/paths.conf: relative path . is [PATH]/selftest/suite_test
+cnf -: DBG: [PATH]/selftest/suite_test/paths.conf: relative path ./test_work/state_dir is [PATH]/selftest/suite_test/test_work/state_dir
+cnf -: DBG: Found path suites_dir as [PATH]/selftest/suite_test
+--- -: ERR: RuntimeError: Suite not found: 'does_not_exist' in [PATH]/selftest/suite_test
 - no suite.conf
+cnf -: DBG: Found path suites_dir as [PATH]/selftest/suite_test
 cnf empty_dir: DBG: reading suite.conf  [empty_dir↪empty_dir]
---- ./suite_test/./empty_dir/suite.conf: ERR: FileNotFoundError: [Errno 2] No such file or directory: './suite_test/./empty_dir/suite.conf'  [empty_dir↪./suite_test/./empty_dir/suite.conf]
+--- [PATH]/selftest/suite_test/empty_dir/suite.conf: ERR: FileNotFoundError: [Errno 2] No such file or directory: '[PATH]/selftest/suite_test/empty_dir/suite.conf'  [empty_dir↪[PATH]/selftest/suite_test/empty_dir/suite.conf]
 - valid suite dir
+cnf -: DBG: Found path suites_dir as [PATH]/selftest/suite_test
 cnf test_suite: DBG: reading suite.conf  [test_suite↪test_suite]
 defaults:
   timeout: 60s
@@ -16,6 +22,8 @@ resources:
   - times: '1'
 
 - run hello world test
+cnf -: DBG: Found config file resources.conf as [PATH]/selftest/suite_test/resources.conf in ./suite_test which is [PATH]/selftest/suite_test
+cnf -: DBG: Found path state_dir as [PATH]/selftest/suite_test/test_work/state_dir
 tst test_suite: Suite run start
 tst test_suite: reserving resources...
 tst test_suite: DBG: {combining='resources'}  [test_suite↪test_suite]

selftest/suite_test.ok.ign

@@ -0,0 +1 @@
+/[^ ]*/selftest/	[PATH]/selftest/

src/osmo_gsm_tester/config.py

@@ -88,9 +88,11 @@ def _get_config_file(basename, fail_if_missing=True):
         locations = DEFAULT_CONFIG_LOCATIONS
 
     for l in locations:
-        p = os.path.join(l, basename)
+        real_l = os.path.realpath(l)
+        p = os.path.realpath(os.path.join(real_l, basename))
         if os.path.isfile(p):
-            return (p, l)
+            log.dbg(None, log.C_CNF, 'Found config file', basename, 'as', p, 'in', l, 'which is', real_l)
+            return (p, real_l)
     if not fail_if_missing:
         return None, None
     raise RuntimeError('configuration file not found: %r in %r' % (basename,
@@ -115,20 +117,25 @@ def get_configured_path(label, allow_unset=False):
     env_name = ENV_PREFIX + label.upper()
     env_path = os.getenv(env_name)
     if env_path:
-        return env_path
+        real_env_path = os.path.realpath(env_path)
+        log.dbg(None, log.C_CNF, 'Found path', label, 'as', env_path, 'in', '$' + env_name, 'which is', real_env_path)
+        return real_env_path
 
     if PATHS is None:
         paths_file, found_in = _get_config_file(PATHS_CONF)
         PATHS = read(paths_file, PATHS_SCHEMA)
         for key, path in PATHS.items():
             if not path.startswith(os.pathsep):
-                PATHS[key] = os.path.join(found_in, path)
+                PATHS[key] = os.path.realpath(os.path.join(found_in, path))
+                log.dbg(None, log.C_CNF, paths_file + ': relative path', path, 'is', PATHS[key])
     p = PATHS.get(label)
     if p is None and not allow_unset:
         raise RuntimeError('missing configuration in %s: %r' % (PATHS_CONF, label))
 
+    log.dbg(None, log.C_CNF, 'Found path', label, 'as', p)
     if p.startswith(PATHS_TEMPDIR_STR):
         p = os.path.join(get_tempdir(), p[len(PATHS_TEMPDIR_STR):])
+        log.dbg(None, log.C_CNF, 'Path', label, 'contained', PATHS_TEMPDIR_STR, 'and becomes', p)
     return p
 
 def get_state_dir():