Make PATH policy controlled

Make the PATH environment variable subject to Policy class
control. Policies may set PATH to an appropriately formatted
string for the platform. This will be exported to the environment
and used as the search path for binaries that sos modules execute.

Following this change all absolute paths can be removed from
plug-in code simplifying maintenance on multiple distributions
and distribution versions (e.g. Red Hat UsrMove and various
updates that relocate binaries such as lsusb).

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>

3 files changed, 29 insertions, 5 deletions

diff --git a/sos/policies/__init__.py b/sos/policies/__init__.py
index d99207ba..8148c894 100644
--- a/sos/policies/__init__.py
+++ b/sos/policies/__init__.py
@@ -5,6 +5,7 @@ import re
 import platform
 import time
 import fnmatch
+from os import environ
 
 from sos.utilities import ImporterHelper, \
                         import_module, \
@@ -133,16 +134,20 @@ No changes will be made to system configuration.
     vendor = "Unknown"
     vendor_url = "http://www.example.com/"
     vendor_text = ""
+    PATH = ""
 
     def __init__(self):
         """Subclasses that choose to override this initializer should call
         super() to ensure that they get the required platform bits attached.
-        super(SubClass, self).__init__()"""
+        super(SubClass, self).__init__(). Policies that require runtime
+        tests to construct PATH must call self.set_exec_path() after
+        modifying PATH in their own initializer."""
         self._parse_uname()
         self.report_name = self.hostname
         self.ticket_number = None
         self.package_manager = PackageManager()
         self._valid_subclasses = []
+        self.set_exec_path()
 
     def get_valid_subclasses(self):
         return [IndependentPlugin] + self._valid_subclasses
@@ -221,6 +226,12 @@ No changes will be made to system configuration.
     def set_commons(self, commons):
         self.commons = commons
 
+    def _set_PATH(self, path):
+        environ['PATH'] = path
+
+    def set_exec_path(self):
+        self._set_PATH(self.PATH)
+        
     def is_root(self):
         """This method should return true if the user calling the script is
         considered to be a superuser"""
@@ -377,6 +388,7 @@ class LinuxPolicy(Policy):
 
     distro = "Linux"
     vendor = "None"
+    PATH = "/bin:/sbin:/usr/bin:/usr/sbin"
 
     def __init__(self):
         super(LinuxPolicy, self).__init__()
diff --git a/sos/policies/debian.py b/sos/policies/debian.py
index 94b089f3..409ba85a 100644
--- a/sos/policies/debian.py
+++ b/sos/policies/debian.py
@@ -11,6 +11,8 @@ class DebianPolicy(LinuxPolicy):
     ticket_number = ""
     package_manager = PackageManager("dpkg-query -W -f='${Package}|${Version}\\n' \*")
     valid_subclasses = [DebianPlugin]
+    PATH = "/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games" \
+            + ":/usr/loca/sbin:/usr/local/bin"
 
     def __init__(self):
         super(DebianPolicy, self).__init__()
diff --git a/sos/policies/redhat.py b/sos/policies/redhat.py
index 7677b806..7a26d811 100644
--- a/sos/policies/redhat.py
+++ b/sos/policies/redhat.py
@@ -40,14 +40,24 @@ class RedHatPolicy(LinuxPolicy):
         super(RedHatPolicy, self).__init__()
         self.report_name = ""
         self.ticket_number = ""
-        self.package_manager = PackageManager('rpm -qa --queryformat "%{NAME}|%{VERSION}\\n"')
+        self.package_manager = PackageManager(
+                        'rpm -qa --queryformat "%{NAME}|%{VERSION}\\n"')
         self.valid_subclasses = [RedHatPlugin]
 
+        # handle PATH for UsrMove
+        if self.package_manager.all_pkgs()['filesystem']['version'][0] == '3':
+            self.PATH = "/usr/sbin:/usr/bin:/root/bin"
+        else:
+            self.PATH = "/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
+        self.PATH += os.pathsep + "/usr/local/bin"
+        self.PATH += os.pathsep + "/usr/local/sbin"
+        self.set_exec_path()
+
     @classmethod
     def check(self):
-        """This method checks to see if we are running on Red Hat. It must be overriden
-        by concrete subclasses to return True when running on a Fedora, RHEL or other
-        Red Hat distribution or False otherwise."""
+        """This method checks to see if we are running on Red Hat. It must be
+        overriden by concrete subclasses to return True when running on a
+        Fedora, RHEL or other Red Hat distribution or False otherwise."""
         return False
 
     def runlevel_by_service(self, name):