modifying wait_for module, wait for cloud-init

playbooks/library/wait_for

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2012, Jeroen Hoekx <jeroen@hoekx.be>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+import socket
+import datetime
+import time
+import sys
+
+DOCUMENTATION = '''
+---
+module: wait_for
+short_description: Waits for a given port to become accessible on a server.
+description:
+     - This is useful for when services are not immediately available after
+       their init scripts return - which is true of certain Java application
+       servers. It is also useful when starting guests with the M(virt) module and
+       needing to pause until they are ready.
+version_added: "0.7"
+options:
+  host:
+    description:
+      - hostname or IP address to wait for
+    required: false
+    default: "127.0.0.1"
+    aliases: []
+  timeout:
+    description:
+      - maximum number of seconds to wait for
+    required: false
+    default: 300
+  delay:
+    description:
+      - number of seconds to wait before starting to poll
+    required: false
+    default: 0
+  port:
+    description:
+      - port number to poll
+    required: true
+  state:
+    description:
+      - either C(started), or C(stopped) depending on whether the module should 
+        poll for the port being open or closed.
+    choices: [ "started", "stopped" ]
+    default: "started"
+notes: []
+requirements: []
+author: Jeroen Hoekx
+'''
+
+EXAMPLES = '''
+# wait 300 seconds for port 8000 to become open on the host, don't start checking for 10 seconds
+- wait_for: port=8000 delay=10"
+'''
+
+def main():
+
+    module = AnsibleModule(
+        argument_spec = dict(
+            host=dict(default='127.0.0.1'),
+            timeout=dict(default=300),
+            connect_timeout=dict(default=5),
+            delay=dict(default=0),
+            port=dict(default=None),
+            path=dict(default=None),
+            search_string=dict(default=None),
+            state=dict(default='started', choices=['started', 'stopped', 'present']),
+        ),
+    )
+
+    params = module.params
+
+    host = params['host']
+    timeout = int(params['timeout'])
+    connect_timeout = int(params['connect_timeout'])
+    delay = int(params['delay'])
+    if params['port']:
+        port = int(params['port'])
+    else:
+        port = None
+    state = params['state']
+    path = params['path']
+    search_string = params['search_string']
+    
+    if port and path:
+        module.fail_json(msg="port and path parameter can not both be passed to wait_for")
+    if path and state == 'stopped':
+        module.fail_json(msg="state=stopped should only be used for checking a port in the wait_for module")
+        
+    start = datetime.datetime.now()
+
+    if delay:
+        time.sleep(delay)
+
+    if state == 'stopped':
+        ### first wait for the stop condition
+        end = start + datetime.timedelta(seconds=timeout)
+
+        while datetime.datetime.now() < end:
+            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s.settimeout(connect_timeout)
+            try:
+                s.connect( (host, port) )
+                s.shutdown(socket.SHUT_RDWR)
+                s.close()
+                time.sleep(1)
+            except:
+                break
+        else:
+            elapsed = datetime.datetime.now() - start
+            module.fail_json(msg="Timeout when waiting for %s:%s to stop." % (host, port), elapsed=elapsed.seconds)
+
+    elif state in ['started', 'present']:
+        ### wait for start condition
+        end = start + datetime.timedelta(seconds=timeout)
+        while datetime.datetime.now() < end:
+            if path:
+                try:
+                    with open(path) as f:
+                        if search_string:
+                            if search_string in f.read():
+                                break
+                            else:
+                                time.sleep(1)
+                        else:
+                            break
+                except IOError:
+                    time.sleep(1)
+                    pass
+            elif port:
+                s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                s.settimeout(connect_timeout)
+                try:
+                    s.connect( (host, port) )
+                    s.shutdown(socket.SHUT_RDWR)
+                    s.close()
+                    break
+                except:
+                    time.sleep(1)
+                    pass
+        else:
+            elapsed = datetime.datetime.now() - start
+            if port:
+                module.fail_json(msg="Timeout when waiting for %s:%s" % (host, port), elapsed=elapsed.seconds)
+            elif path:
+                if search_string:
+                    module.fail_json(msg="Timeout when waiting for search string %s in %s" % (search_string, path), elapsed=elapsed.seconds)
+                else:
+                    module.fail_json(msg="Timeout when waiting for file %s" % (path), elapsed=elapsed.seconds)
+
+
+    elapsed = datetime.datetime.now() - start
+    module.exit_json(state=state, port=port, search_string=search_string, path=path, elapsed=elapsed.seconds)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+main()

playbooks/roles/launch_ec2/tasks/main.yml

@@ -90,3 +90,10 @@
       delay=60
       timeout=320
   with_items: "{{ ec2.instances }}"
+
+- name: launch_ec2 | Wait for cloud-init to finish
+  wait_for: >
+    path=/var/log/cloud-init.log
+    timouet=15
+    search_string=final-message
+  delegate_to: "{{ item.public_dns_name }}"