Alphabetic inventory hostname patterns.

- Code, docs, tests.
  - Also added test of large range 000-142 to verify alpha range did not
    break this.

docsite/rst/patterns.rst

@@ -48,8 +48,9 @@ Adding a lot of hosts?  In 0.6 and later, if you have a lot of hosts following s
 
     [webservers]
     www[01:50].example.com
+    db-[a:f].example.com
 
-Leading zeros can be included or removed, as desired, and the ranges are inclusive.
+For numeric patterns, leading zeros can be included or removed, as desired. Ranges are inclusive.
 
 Selecting Targets
 +++++++++++++++++

lib/ansible/inventory/expand_hosts.py

@@ -20,8 +20,8 @@
 '''
 This module is for enhancing ansible's inventory parsing capability such
 that it can deal with hostnames specified using a simple pattern in the
-form of [beg:end], example: [1:5] where if beg is not specified, it
-defaults to 0.
+form of [beg:end], example: [1:5], [a:c], [D:G]. If beg is not specified,
+it defaults to 0.
 
 If beg is given and is left-zero-padded, e.g. '001', it is taken as a
 formatting hint when the range is expanded. e.g. [001:010] is to be
@@ -30,6 +30,7 @@ expanded into 001, 002 ...009, 010.
 Note that when beg is specified with left zero padding, then the length of
 end must be the same as that of beg, else a exception is raised.
 '''
+import string
 
 from ansible import errors
 
@@ -81,17 +82,23 @@ def expand_hostname_range(line = None):
             raise errors.AnsibleError("host range end value missing")
         if beg[0] == '0' and len(beg) > 1:
             rlen = len(beg) # range length formatting hint
+            if rlen != len(end):
+                raise errors.AnsibleError("host range format incorrectly specified!")
+            fill = lambda _: str(_).zfill(rlen)  # range sequence
         else:
-            rlen = None
-        if rlen > 1 and rlen != len(end):
-            raise errors.AnsibleError("host range format incorrectly specified!")
+            fill = str
 
-        for _ in range(int(beg), int(end)+1):
-            if rlen:
-                rseq = str(_).zfill(rlen) # range sequence
-            else:
-                rseq = str(_)
-            hname = ''.join((head, rseq, tail))
+        try:
+            i_beg = string.ascii_letters.index(beg)
+            i_end = string.ascii_letters.index(end)
+            if i_beg > i_end:
+                raise errors.AnsibleError("host range format incorrectly specified!")
+            seq = string.ascii_letters[i_beg:i_end+1]
+        except ValueError:  # not a alpha range
+            seq = range(int(beg), int(end)+1)
+
+        for rseq in seq:
+            hname = ''.join((head, fill(rseq), tail))
             all_hosts.append(hname)
 
         return all_hosts

test/TestInventory.py

@@ -9,9 +9,10 @@ class TestInventory(unittest.TestCase):
         self.cwd = os.getcwd()
         self.test_dir = os.path.join(self.cwd, 'test')
 
-        self.inventory_file         = os.path.join(self.test_dir, 'simple_hosts')
-        self.complex_inventory_file = os.path.join(self.test_dir, 'complex_hosts')
-        self.inventory_script       = os.path.join(self.test_dir, 'inventory_api.py')
+        self.inventory_file             = os.path.join(self.test_dir, 'simple_hosts')
+        self.large_range_inventory_file = os.path.join(self.test_dir, 'large_range')
+        self.complex_inventory_file     = os.path.join(self.test_dir, 'complex_hosts')
+        self.inventory_script           = os.path.join(self.test_dir, 'inventory_api.py')
 
         os.chmod(self.inventory_script, 0755)
 
@@ -29,38 +30,36 @@ class TestInventory(unittest.TestCase):
     def simple_inventory(self):
         return Inventory(self.inventory_file)
 
+    def large_range_inventory(self):
+        return Inventory(self.large_range_inventory_file)
+
     def script_inventory(self):
         return Inventory(self.inventory_script)
 
     def complex_inventory(self):
         return Inventory(self.complex_inventory_file)
 
+    all_simple_hosts=['jupiter', 'saturn', 'zeus', 'hera',
+            'cerberus001','cerberus002','cerberus003',
+            'cottus99', 'cottus100',
+            'poseidon', 'thor', 'odin', 'loki',
+            'thrudgelmir0', 'thrudgelmir1', 'thrudgelmir2',
+            'thrudgelmir3', 'thrudgelmir4', 'thrudgelmir5',
+            'Hotep-a', 'Hotep-b', 'Hotep-c',
+            'BastC', 'BastD', ]
+
     #####################################
     ### Simple inventory format tests
 
     def test_simple(self):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts()
-
-        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)
+        self.assertEqual(sorted(hosts), sorted(self.all_simple_hosts))
 
     def test_simple_all(self):
         inventory = self.simple_inventory()
         hosts = inventory.list_hosts('all')
-
-        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)
+        self.assertEqual(sorted(hosts), sorted(self.all_simple_hosts))
 
     def test_simple_norse(self):
         inventory = self.simple_inventory()
@@ -132,6 +131,11 @@ class TestInventory(unittest.TestCase):
         print expected
         assert vars == expected
 
+    def test_large_range(self):
+        inventory = self.large_range_inventory()
+        hosts = inventory.list_hosts()
+        self.assertEqual(sorted(hosts),  sorted('bob%03i' %i  for i in range(0, 143)))
+
     ###################################################
     ### INI file advanced tests
 

test/large_range

@@ -0,0 +1 @@
+bob[000:142]

test/simple_hosts

@@ -13,3 +13,7 @@ cottus[99:100]
 thor
 odin
 loki
+
+[egyptian]
+Hotep-[a:c]
+Bast[C:D]