Merge pull request #9 from schaal/path-unit

Add path unit to monitor changes to crontab files.

README.md

@@ -49,14 +49,10 @@ execute commands from `package()` sub.
 
 ## Usage
 
-The generator runs on system boot. If you change your crontabs in runtime, run `systemd-crontab-update`
-script as root (`sudo systemd-crontab-update`) to regenerate systemd units and reload them.
+The generator runs on system boot and when the crontabs change.
 
 The project includes simple `crontab` command equivalent, which behaves like standard crontab command
-(and accepts the same main options), and runs `systemd-crontab-update` command after user crontab file
-update. Note, though, the systemd-crontab-update requires superuser priviledges, so `crontab` tries
-to run it under `sudo`, so if you are not allowed to run `systemd-crontab-update` via `/etc/sudoers`
-file, you can't update crontab timers.
+(and accepts the same main options).
 
 To control cron jobs, use `cron.target`, e.g. to start and enable cron after installation:
 

crontab

@@ -41,10 +41,6 @@ args_parser.add_argument('-i', '--ask', dest='ask', action='store_true', default
  #MLS_LEVEL setting to the crontab file before editing / replacement occurs
  #- see the documentation of MLS_LEVEL in crontab(5).''')
 
-def update():
-    sudo = '' if os.getuid() == 0 else '/usr/bin/sudo '
-    os.system('%s/usr/bin/systemd-crontab-update' % sudo)
-
 def confirm(message):
     while True:
         answer = raw_input(message).lower()
@@ -61,7 +57,6 @@ def list(cron_file, args):
 def remove(cron_file, args):
     if not args.ask or confirm('Are you sure you want to delete %s (y/n)? ' % cron_file):
         os.unlink(cron_file)
-        update()
 
 def edit(cron_file, args):
     with tempfile.NamedTemporaryFile() as tmp:
@@ -74,8 +69,6 @@ def edit(cron_file, args):
             tmp.file.seek(0)
             with open(cron_file, 'w') as out:
                 out.write(tmp.file.read())
-                
-    update()
 
 def replace(cron_file, args):
     infile = args.file
@@ -87,8 +80,6 @@ def replace(cron_file, args):
         with open(cron_file, 'w'), open(infile, 'r') as out, inp:
             out.write(inp.read())
 
-    update()
-
 if __name__ == '__main__':
     args = args_parser.parse_args()
     cron_file = os.path.join(CRONTAB_DIR, args.user)

systemd-crontab-generator

@@ -233,6 +233,39 @@ ExecStart=%s -c '%s'
 
     return '%s.timer' % unit_name
 
+def generate_path_unit():
+    combinedcronfiles = [ '/etc/crontab', '/etc/cron.d', '/etc/anacrontab', '/var/spool/cron' ]
+    with open('%s/systemd-crontab-update.path' % (TARGER_DIR), 'w') as f:
+        f.write('''# Automatically generated by %s
+
+[Unit]
+Description=[Cron] Update cron units
+RefuseManualStart=true
+RefuseManualStop=true
+
+[Path]
+%s
+''' % (SELF,'\n'.join([ "PathChanged="+f for f in combinedcronfiles ]) ))
+
+    try:
+        os.symlink('%s/systemd-crontab-update.path' % (TARGER_DIR), '%s/systemd-crontab-update.path' % (TIMERS_DIR))
+    except OSError as e:
+        if e.errno != os.errno.EEXIST:
+            raise
+
+    with open('%s/systemd-crontab-update.service' % (TARGER_DIR), 'w') as f:
+        f.write('''# Automatically generated by %s
+
+[Unit]
+Description=[Cron] Update cron units
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/systemd-crontab-update
+''' % (SELF))
+
+    return "systemd-crontab-update.path"
+
 seqs = {}
 def count():
     n = 0
@@ -262,3 +295,7 @@ for filename in USERCRONTAB_FILES:
     except IOError:
         pass
 
+try:
+    generate_path_unit()
+except IOError:
+    pass