Merge pull request ceph#32860 from shyukri/wip-43281-nautilus

nautilus: ceph-volume: util: look for executable in $PATH

src/ceph-volume/ceph_volume/tests/util/test_system.py

@@ -206,18 +206,17 @@ def test_executable_does_not_exist(self, monkeypatch):
         assert system.which('exedir') == 'exedir'
 
     def test_executable_exists_as_file(self, monkeypatch):
-        monkeypatch.setattr(system.os.path, 'isfile', lambda x: True)
-        monkeypatch.setattr(system.os.path, 'exists', lambda x: True)
+        monkeypatch.setattr(system.os, 'getenv', lambda x, y: '')
+        monkeypatch.setattr(system.os.path, 'isfile', lambda x: x != 'ceph')
+        monkeypatch.setattr(system.os.path, 'exists', lambda x: x != 'ceph')
         assert system.which('ceph') == '/usr/local/bin/ceph'
 
     def test_warnings_when_executable_isnt_matched(self, monkeypatch, capsys):
         monkeypatch.setattr(system.os.path, 'isfile', lambda x: True)
         monkeypatch.setattr(system.os.path, 'exists', lambda x: False)
         system.which('exedir')
         cap = capsys.readouterr()
-        assert 'Absolute path not found for executable: exedir' in cap.err
-        assert 'Ensure $PATH environment variable contains common executable locations' in cap.err
-
+        assert 'Executable exedir not in PATH' in cap.err
 
 @pytest.fixture
 def stub_which(monkeypatch):

src/ceph-volume/ceph_volume/util/system.py

@@ -39,21 +39,32 @@ def generate_uuid():
 
 def which(executable):
     """find the location of an executable"""
-    locations = (
+    def _get_path(executable, locations):
+        for location in locations:
+            executable_path = os.path.join(location, executable)
+            if os.path.exists(executable_path) and os.path.isfile(executable_path):
+                return executable_path
+        return None
+
+    path = os.getenv('PATH', '')
+    path_locations = path.split(':')
+    exec_in_path = _get_path(executable, path_locations)
+    if exec_in_path:
+        return exec_in_path
+    mlogger.warning('Executable {} not in PATH: {}'.format(executable, path))
+
+    static_locations = (
         '/usr/local/bin',
         '/bin',
         '/usr/bin',
         '/usr/local/sbin',
         '/usr/sbin',
         '/sbin',
     )
-
-    for location in locations:
-        executable_path = os.path.join(location, executable)
-        if os.path.exists(executable_path) and os.path.isfile(executable_path):
-            return executable_path
-    mlogger.warning('Absolute path not found for executable: %s', executable)
-    mlogger.warning('Ensure $PATH environment variable contains common executable locations')
+    exec_in_static_locations = _get_path(executable, static_locations)
+    if exec_in_static_locations:
+        mlogger.warning('Found executable under {}, please ensure $PATH is set correctly!'.format(exec_in_static_locations))
+        return exec_in_static_locations
     # fallback to just returning the argument as-is, to prevent a hard fail,
     # and hoping that the system might have the executable somewhere custom
     return executable