Added a host expansion feature to ansible's inventory parsing

CHANGELOG.md

@@ -3,6 +3,11 @@ Ansible Changes By Release
 
 0.6 "Cabo" ------------ pending
 
+* inventory file can use a line of the form base[beg:end]tail to define a
+  set of hosts, where [beg:end] defines a numerical range. 'beg' can be a
+  a string padded with zero(s) to the left. If so provided, it acts as
+  a formatting hint during hostname expansion. The hint must be confirmed
+  by having an 'end' that has the same length as 'beg'
 * groups variable available as a hash to return the hosts in each group name
 * fetch module now does not fail a system when requesting file paths (ex: logs) that don't exist
 * apt module now takes an optional install-recommends=yes|no (default yes)

Makefile

@@ -6,7 +6,7 @@
 # useful targets:
 #   make sdist ---------------- produce a tarball
 #   make rpm  ----------------- produce RPMs
-#   make debian --------------- produce a dpkg (FIXME?)
+#   make deb ------------------ produce a DEB
 #   make docs ----------------- rebuild the manpages (results are checked in)
 #   make tests ---------------- run the tests
 #   make pyflakes, make pep8 -- source code checks  

docs/man/man1/ansible.1

@@ -140,7 +140,19 @@ Connection type to use\&. Possible options are
 .RE
 .SH "INVENTORY"
 .sp
-Ansible stores the hosts it can potentially operate on in an inventory file\&. The syntax is one host per line\&. Groups headers are allowed and are included on their own line, enclosed in square brackets\&.
+Ansible stores the hosts it can potentially operate on in an inventory
+file\&. The syntax is one host per line\&. Optionally, ansible can use a
+line of the form base[beg:end]tail to define a set of hosts, where
+[beg:end] defines a numerical range. If 'beg' is left out, it
+defaults to 0\&.  An example: mail[1:6].example.com, where 'head'
+is 'mail', 'beg' is 1, 'end' is 6, and 'tail' is '.example.com'\&. In
+addition, 'beg' can be a a string padded with zero(s) to the left. If so
+provided, it acts as a formatting hint during hostname expansion. The usage
+must be confirmed by having an 'end' that has the same length as 'beg',
+else an exception is raised. An example: mail[001:003].example.com is to be
+expanded to mail001.example.com, mail002.example.com, and
+mail003.example.com\&. Groups headers are allowed and are included on their
+own line, enclosed in square brackets\&.
 .SH "FILES"
 .sp
 /etc/ansible/hosts \(em Default inventory file

examples/hosts

@@ -16,6 +16,8 @@ bikeshed.org
 bastion.secure.bikeshed.org
 192.168.100.1
 192.168.100.10
+# An example for host expansion that uses the default 'beg' and an 'end'
+mail[:5].example.com
 
 # Ex 2: A collection of hosts belonging to the 'webservers' group
 [webservers]
@@ -26,6 +28,9 @@ wheel.colors.com
 192.168.1.110
 # Your personal website also runs a webserver:
 myserver.com
+# An example for host expansion that uses both a 'beg' and an 'end', with
+# the 'beg' acting as a formatting hint during host name expansion
+www[001:006].example.com
 
 # Ex 3: A collection of database servers in the 'dbservers' group
 [dbservers]
@@ -35,3 +40,6 @@ db02.intranet.mydomain.net
 10.25.1.57
 # Perhaps you serve a db off your personal server too:
 myserver.com
+# An example for host expansion that uses a regular 'beg' and a regular
+# 'end'
+db-[99:101]-node.example.com

lib/ansible/inventory/ini.py

@@ -24,6 +24,8 @@ import subprocess
 import ansible.constants as C
 from ansible.inventory.host import Host
 from ansible.inventory.group import Group
+from ansible.inventory.expand_hosts import detect_range
+from ansible.inventory.expand_hosts import expand_hostname_range
 from ansible import errors
 from ansible import utils
 
@@ -80,21 +82,40 @@ class InventoryParser(object):
                     continue
                 hostname = tokens[0]
                 port = C.DEFAULT_REMOTE_PORT
-                if hostname.find(":") != -1:
+                # Two cases to check:
-                    tokens2  = hostname.split(":")
+                # 0. A hostname that contains a range pesudo-code and a port
+                # 1. A hostname that contains just a port
+                if (hostname.find("[") != -1 and
+                    hostname.find("]") != -1 and
+                    hostname.find(":") != -1 and
+                    (hostname.rindex("]") < hostname.rindex(":")) or
+                    (hostname.find("]") == -1 and hostname.find(":") != -1)):
+                        tokens2  = hostname.rsplit(":", 1)
                         hostname = tokens2[0]
                         port     = tokens2[1]
+                
                 host = None
+                _all_hosts = []
                 if hostname in self.hosts:
                     host = self.hosts[hostname]
+                    _all_hosts.append(host)
+                else:
+                    if detect_range(hostname):
+                        _hosts = expand_hostname_range(hostname)
+                        for _ in _hosts:
+                            host = Host(name=_, port=port)
+                            self.hosts[_] = host
+                            _all_hosts.append(host)
                     else:
                         host = Host(name=hostname, port=port)
                         self.hosts[hostname] = host
+                        _all_hosts.append(host)
                 if len(tokens) > 1:
                     for t in tokens[1:]:
                         (k,v) = t.split("=")
                         host.set_variable(k,v)
-                self.groups[active_group_name].add_host(host)
+                for _ in _all_hosts:
+                    self.groups[active_group_name].add_host(_)
 
     # [southeast:children]
     # atlanta

test/TestInventory.py

@@ -44,14 +44,24 @@ class TestInventory(unittest.TestCase):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts()
 
-        expected_hosts=['jupiter', 'saturn', 'zeus', 'hera', 'poseidon', 'thor', 'odin', 'loki']
+        expected_hosts=['jupiter', 'saturn', 'zeus', 'hera', 
+                        'cerberus001','cerberus002','cerberus003',
+                        'cottus99', 'cottus100',
+                        'poseidon', 'thor', 'odin', 'loki',
+                        'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2', 
+                        'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5']
         assert sorted(hosts) == sorted(expected_hosts)
 
     def test_simple_all(self):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts('all')
 
-        expected_hosts=['jupiter', 'saturn', 'zeus', 'hera', 'poseidon', 'thor', 'odin', 'loki']
+        expected_hosts=['jupiter', 'saturn', 'zeus', 'hera', 
+                        'cerberus001','cerberus002','cerberus003',
+                        'cottus99', 'cottus100',
+                        'poseidon', 'thor', 'odin', 'loki',
+                        'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2', 
+                        'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5']
         assert sorted(hosts) == sorted(expected_hosts)
 
     def test_simple_norse(self):
@@ -65,21 +75,29 @@ class TestInventory(unittest.TestCase):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts("ungrouped")
 
-        expected_hosts=['jupiter', 'saturn']
+        expected_hosts=['jupiter', 'saturn', 
+                        'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2', 
+                        'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5']
         assert sorted(hosts) == sorted(expected_hosts)
 
     def test_simple_combined(self):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts("norse:greek")
 
-        expected_hosts=['zeus', 'hera', 'poseidon', 'thor', 'odin', 'loki']
+        expected_hosts=['zeus', 'hera', 'poseidon', 
+                        'cerberus001','cerberus002','cerberus003',
+                        'cottus99','cottus100',
+                        'thor', 'odin', 'loki']
         assert sorted(hosts) == sorted(expected_hosts)
 
     def test_simple_restrict(self):
         inventory = self.simple_inventory()
 
         restricted_hosts = ['hera', 'poseidon', 'thor']
-        expected_hosts=['zeus', 'hera', 'poseidon', 'thor', 'odin', 'loki']
+        expected_hosts=['zeus', 'hera', 'poseidon', 
+                        'cerberus001','cerberus002','cerberus003',
+                        'cottus99', 'cottus100',
+                        'thor', 'odin', 'loki']
 
         inventory.restrict_to(restricted_hosts)
         hosts = inventory.list_hosts("norse:greek")
@@ -99,11 +117,15 @@ class TestInventory(unittest.TestCase):
         inventory = self.simple_inventory()
 
         hosts = inventory.list_hosts("all:!greek")
-        expected_hosts=['jupiter', 'saturn', 'thor', 'odin', 'loki']
+        expected_hosts=['jupiter', 'saturn', 'thor', 'odin', 'loki',
+                        'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2', 
+                        'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5']
         assert sorted(hosts) == sorted(expected_hosts)
 
         hosts = inventory.list_hosts("all:!norse:!greek")
-        expected_hosts=['jupiter', 'saturn']
+        expected_hosts=['jupiter', 'saturn',
+                        'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2', 
+                        'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5']
         assert sorted(hosts) == sorted(expected_hosts)
 
     def test_simple_vars(self):

test/simple_hosts

@@ -1,10 +1,13 @@
 jupiter
 saturn
+thrudgelmir[:6]
 
 [greek]
 zeus
 hera:3000
 poseidon
+cerberus[001:004]
+cottus[99:101]
 
 [norse]
 thor