From d308254eaeefd86c494cc322459af131aa5428a7 Mon Sep 17 00:00:00 2001
From: Michael DeHaan <michael.dehaan@gmail.com>
Date: Sat, 25 Feb 2012 20:27:11 -0500
Subject: [PATCH] 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.
---
 examples/playbook.yml   |  2 +-
 lib/ansible/playbook.py |  1 -
 library/service         | 86 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 2 deletions(-)
 create mode 100755 library/service

diff --git a/examples/playbook.yml b/examples/playbook.yml
index 800108b0cd..9f102a9b5e 100644
--- a/examples/playbook.yml
+++ b/examples/playbook.yml
@@ -21,7 +21,7 @@
   handlers:
     - do:
       - restart apache
-      - command /sbin/service httpd restart
+      - service name=httpd ensure=restarted
     - do:
       - quack like a duck
       - command /bin/true
diff --git a/lib/ansible/playbook.py b/lib/ansible/playbook.py
index 79f7351ad3..6c2df6ab62 100755
--- a/lib/ansible/playbook.py
+++ b/lib/ansible/playbook.py
@@ -21,7 +21,6 @@
 
 import ansible.runner
 import ansible.constants as C
-import json
 import yaml
 import shlex
 
diff --git a/library/service b/library/service
new file mode 100755
index 0000000000..682d3b76f5
--- /dev/null
+++ b/library/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
+})
+