swupd: Ensure we use sudo only when necessary

It may happen that python-swupd is used in an EUID 0 root process, as such
running sudo is not appropriate. With this change, we introduce a command
builder that will insert sudo as appropriate, depending on the current
EUID.

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>

swupd/__init__.py

@@ -49,6 +49,13 @@ def get_installed_bundles():
     return p
 
 
+def _get_swupd_base_command(command):
+    """ Return the base part of the command based on the EUID """
+    if os.geteuid() != 0:
+        return ['sudo', 'swupd', command]
+    return ['swupd', command]
+
+
 def install_bundles(bundle_list, F=None, url=None):
     latest_version = get_latest_version()
     installed_bundles = get_installed_bundles()
@@ -66,7 +73,7 @@ def install_bundles(bundle_list, F=None, url=None):
             err = ""
             exit_status = 1
         else:
-            cmd = ['sudo', 'swupd', 'bundle-add']
+            cmd = _get_swupd_base_command('bundle-add')
             if bundle in bundle_universe:
                 cmd += [bundle]
                 if F is not None:
@@ -98,7 +105,9 @@ def remove_bundles(bundle_list):
     err_ = ""
     for bundle in bundle_list:
         if(bundle in installed_bundles):
-            p = subprocess.Popen(['sudo', 'swupd', 'bundle-remove', bundle],
+            cmd = _get_swupd_base_command('bundle-remove')
+            cmd.append(bundle)
+            p = subprocess.Popen(cmd,
                                  stdout=subprocess.PIPE,
                                  stderr=subprocess.PIPE)
             o, e = p.communicate()
@@ -117,7 +126,8 @@ def update():
     exit_status = 0
     out = ""
     err = ""
-    p = subprocess.Popen(['sudo', 'swupd', 'update'],
+    cmd = _get_swupd_base_command('update')
+    p = subprocess.Popen(cmd,
                          stdout=subprocess.PIPE,
                          stderr=subprocess.PIPE)
     out, err = p.communicate()