A basic service module with 'ensure' idempotence semantics. Playbook updated to use service

module vs command module for restarting.  May be some bugs and requires the service to implement 'status' -- and probably some better error handling (i.e. return JSON with "failed" element if failed).

Improvements welcome.

service

@@ -0,0 +1,86 @@
+#!/usr/bin/python
+
+try:
+    import json
+except ImportError:
+    import simplejson as json
+import os
+import sys
+import shlex
+import subprocess
+
+# ===========================================
+# convert arguments of form ensure=running name=foo
+# to a dictionary
+# FIXME: make more idiomatic
+
+args = " ".join(sys.argv[1:])
+items = shlex.split(args)
+params = {}
+for x in items:
+    (k, v) = x.split("=")
+    params[k] = v
+
+name = params['name']
+ensure = params.get('ensure','running')
+
+# ===========================================
+# get service status
+
+status = os.popen("/sbin/service %s status" % name).read()
+
+# ===========================================
+# determine if we are going to change anything
+
+running = False
+if status.find("not running") != -1:
+    running = False
+elif status.find("running") != -1:
+    running = True
+elif name == 'iptables' and status.find("ACCEPT") != -1:
+    # iptables status command output is lame
+    # TODO: lookup if we can use a return code for this instead?
+    running = True
+
+changed = False
+if not running and ensure == "started":
+    changed = True
+elif running and ensure == "stopped":
+    changed = True
+elif ensure == "restarted":
+    changed = True
+
+# ===========================================
+# run change commands if we need to
+
+def _run(cmd):
+    return subprocess.call(cmd, 
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE, shell=True)
+
+
+rc = 0
+if changed:
+    if ensure == 'started':
+        rc = _run("/sbin/service %s start" %  name)
+    elif ensure == 'stopped':
+        rc = _run("/sbin/service %s stop" % name)
+    elif ensure == 'restarted':
+        rc1 = _run("/sbin/service %s stop" % name)
+        rc2 = _run("/sbin/service %s start" % name)
+        rc  = rc1 and rc2
+
+if rc != 0:
+    # yeah, should probably include output of failure...
+    print json.dumps({
+        "failed" : 1
+    })
+    sys.exit(1)
+
+# ===============================================
+# success
+
+print json.dumps({
+   "changed" : changed
+})
+