Merge pull request #12009 from amenonsen/inventory-ini-rewrite

Rewrite inventory/ini.py
This commit is contained in:
Toshio Kuratomi 2015-08-20 09:51:19 -07:00
commit ceb66c7fd9

View file

@ -1,4 +1,4 @@
# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
# Copyright 2015 Abhijit Menon-Sen <ams@2ndQuadrant.com>
#
# This file is part of Ansible
#
@ -33,28 +33,282 @@ from ansible.utils.unicode import to_unicode
class InventoryParser(object):
"""
Host inventory for ansible.
Takes an INI-format inventory file and builds a list of groups and subgroups
with their associated hosts and variable settings.
"""
def __init__(self, filename=C.DEFAULT_HOST_LIST):
self.filename = filename
# Start with an empty host list and the default 'all' and
# 'ungrouped' groups.
self.hosts = {}
self.patterns = {}
self.groups = dict(
all = Group(name='all'),
ungrouped = Group(name='ungrouped')
)
# Read in the hosts, groups, and variables defined in the
# inventory file.
with open(filename) as fh:
self.lines = fh.readlines()
self.groups = {}
self.hosts = {}
self._parse()
self._parse(fh.readlines())
def _parse(self):
# Finally, add all top-level groups (including 'ungrouped') as
# children of 'all'.
self._parse_base_groups()
self._parse_group_children()
self._add_allgroup_children()
self._parse_group_variables()
return self.groups
for group in self.groups.values():
if group.depth == 0 and group.name != 'all':
self.groups['all'].add_child_group(group)
# Note: we could discard self.hosts after this point.
def _raise_error(self, message):
raise AnsibleError("%s:%d: " % (self.filename, self.lineno) + message)
def _parse(self, lines):
'''
Populates self.groups from the given array of lines. Raises an error on
any parse failure.
'''
self._compile_patterns()
# We behave as though the first line of the inventory is '[ungrouped]',
# and begin to look for host definitions. We make a single pass through
# each line of the inventory, building up self.groups and adding hosts,
# subgroups, and setting variables as we go.
pending_declarations = {}
groupname = 'ungrouped'
state = 'hosts'
self.lineno = 0
for line in lines:
self.lineno += 1
line = line.strip()
# Skip empty lines and comments
if line == '' or line.startswith(";") or line.startswith("#"):
continue
# Is this a [section] header? That tells us what group we're parsing
# definitions for, and what kind of definitions to expect.
m = self.patterns['section'].match(line)
if m:
(groupname, state) = m.groups()
state = state or 'hosts'
if state not in ['hosts', 'children', 'vars']:
title = ":".join(m.groups())
self._raise_error("Section [%s] has unknown type: %s" % (title, state))
# If we haven't seen this group before, we add a new Group.
#
# Either [groupname] or [groupname:children] is sufficient to
# declare a group, but [groupname:vars] is allowed only if the
# group is declared elsewhere (not necessarily earlier). We add
# the group anyway, but make a note in pending_declarations to
# check at the end.
if groupname not in self.groups:
self.groups[groupname] = Group(name=groupname)
if state == 'vars':
pending_declarations[groupname] = dict(line=self.lineno, state=state, name=groupname)
# When we see a declaration that we've been waiting for, we can
# delete the note.
if groupname in pending_declarations and state != 'vars':
del pending_declarations[groupname]
continue
# It's not a section, so the current state tells us what kind of
# definition it must be. The individual parsers will raise an
# error if we feed them something they can't digest.
# [groupname] contains host definitions that must be added to
# the current group.
if state == 'hosts':
hosts = self._parse_host_definition(line)
for h in hosts:
self.groups[groupname].add_host(h)
# [groupname:vars] contains variable definitions that must be
# applied to the current group.
elif state == 'vars':
(k, v) = self._parse_variable_definition(line)
self.groups[groupname].set_variable(k, v)
# [groupname:children] contains subgroup names that must be
# added as children of the current group. The subgroup names
# must themselves be declared as groups, but as before, they
# may only be declared later.
elif state == 'children':
child = self._parse_group_name(line)
if child not in self.groups:
self.groups[child] = Group(name=child)
pending_declarations[child] = dict(line=self.lineno, state=state, name=child, parent=groupname)
self.groups[groupname].add_child_group(self.groups[child])
# Note: there's no reason why we couldn't accept variable
# definitions here, and set them on the named child group.
# This is a fencepost. It can happen only if the state checker
# accepts a state that isn't handled above.
else:
self._raise_error("Entered unhandled state: %s" % (state))
# Any entries in pending_declarations not removed by a group declaration
# above mean that there was an unresolved forward reference. We report
# only the first such error here.
for g in pending_declarations:
decl = pending_declarations[g]
if decl['state'] == 'vars':
raise AnsibleError("%s:%d: Section [%s:vars] not valid for undefined group: %s" % (self.filename, decl['line'], decl['name'], decl['name']))
elif decl['state'] == 'children':
raise AnsibleError("%s:%d: Section [%s:children] includes undefined group: %s" % (self.filename, decl['line'], decl['parent'], decl['name']))
def _parse_group_name(self, line):
'''
Takes a single line and tries to parse it as a group name. Returns the
group name if successful, or raises an error.
'''
m = self.patterns['groupname'].match(line)
if m:
return m.group(1)
self._raise_error("Expected group name, got: %s" % (line))
def _parse_variable_definition(self, line):
'''
Takes a string and tries to parse it as a variable definition. Returns
the key and value if successful, or raises an error.
'''
# TODO: We parse variable assignments as a key (anything to the left of
# an '='"), an '=', and a value (anything left) and leave the value to
# _parse_value to sort out. We should be more systematic here about
# defining what is acceptable, how quotes work, and so on.
if '=' in line:
(k, v) = [e.strip() for e in line.split("=", 1)]
return (k, self._parse_value(v))
self._raise_error("Expected key=value, got: %s" % (line))
def _parse_host_definition(self, line):
'''
Takes a single line and tries to parse it as a host definition. Returns
a list of Hosts if successful, or raises an error.
'''
# A host definition comprises (1) a non-whitespace hostname or range,
# optionally followed by (2) a series of key="some value" assignments.
# We ignore any trailing whitespace and/or comments. For example, here
# are a series of host definitions in a group:
#
# [groupname]
# alpha
# beta:2345 user=admin # we'll tell shlex
# gamma sudo=True user=root # to ignore comments
try:
tokens = shlex.split(line, comments=True)
except ValueError as e:
self._raise_error("Error parsing host definition '%s': %s" % (varstring, e))
(hostnames, port) = self._expand_hostpattern(tokens[0])
hosts = self._Hosts(hostnames, port)
# Try to process anything remaining as a series of key=value pairs.
variables = {}
for t in tokens[1:]:
if '=' not in t:
self._raise_error("Expected key=value host variable assignment, got: %s" % (t))
(k, v) = t.split('=', 1)
variables[k] = self._parse_value(v)
# Apply any variable settings found to every host.
for h in hosts:
for k in variables:
h.set_variable(k, variables[k])
if k == 'ansible_ssh_host':
h.ipv4_address = variables[k]
return hosts
def _expand_hostpattern(self, hostpattern):
'''
Takes a single host pattern and returns a list of hostnames and an
optional port number that applies to all of them.
'''
# Is a port number specified?
#
# This may be a mandatory :NN suffix on any square-bracketed expression
# (IPv6 address, IPv4 address, host name, host pattern), or an optional
# :NN suffix on an IPv4 address, host name, or pattern. IPv6 addresses
# must be in square brackets if a port is specified.
port = None
for type in ['bracketed_hostport', 'hostport']:
m = self.patterns[type].match(hostpattern)
if m:
(hostpattern, port) = m.groups()
continue
# Now we're left with just the pattern, which results in a list of one
# or more hostnames, depending on whether it contains any [x:y] ranges.
#
# FIXME: We could be more strict here about validation.
if detect_range(hostpattern):
hostnames = expand_hostname_range(hostpattern)
else:
hostnames = [hostpattern]
return (hostnames, port)
def _Hosts(self, hostnames, port):
'''
Takes a list of hostnames and a port (which may be None) and returns a
list of Hosts (without recreating anything in self.hosts).
'''
hosts = []
# Note that we decide whether or not to create a Host based solely on
# the (non-)existence of its hostname in self.hosts. This means that one
# cannot add both "foo:22" and "foo:23" to the inventory. This behaviour
# is preserved for now, but this may be an easy FIXME.
for hn in hostnames:
if hn not in self.hosts:
self.hosts[hn] = Host(name=hn, port=port)
hosts.append(self.hosts[hn])
return hosts
@staticmethod
def _parse_value(v):
'''
Does something with something and returns something. Not for mere
mortals such as myself to interpret.
'''
if "#" not in v:
try:
v = ast.literal_eval(v)
@ -68,158 +322,72 @@ class InventoryParser(object):
pass
return to_unicode(v, nonstring='passthru', errors='strict')
# [webservers]
# alpha
# beta:2345
# gamma sudo=True user=root
# delta asdf=jkl favcolor=red
def _add_allgroup_children(self):
for group in self.groups.values():
if group.depth == 0 and group.name != 'all':
self.groups['all'].add_child_group(group)
def _parse_base_groups(self):
# FIXME: refactor
ungrouped = Group(name='ungrouped')
all = Group(name='all')
all.add_child_group(ungrouped)
self.groups = dict(all=all, ungrouped=ungrouped)
active_group_name = 'ungrouped'
i = 0
for line in self.lines:
i += 1
line = self._before_comment(line).strip()
if line.startswith("[") and line.endswith("]"):
active_group_name = line.replace("[","").replace("]","")
if ":vars" in line or ":children" in line:
active_group_name = active_group_name.rsplit(":", 1)[0]
if active_group_name not in self.groups:
new_group = self.groups[active_group_name] = Group(name=active_group_name)
active_group_name = None
elif active_group_name not in self.groups:
new_group = self.groups[active_group_name] = Group(name=active_group_name)
elif line.startswith(";") or line == '':
pass
elif active_group_name:
try:
tokens = shlex.split(line)
except ValueError as e:
raise AnsibleError("Error in %s, unable to parse L#%d: %s\n\n\t%s\n" % (self.filename, i, str(e), line))
if len(tokens) == 0:
continue
hostname = tokens[0]
port = None
# Three cases to check:
# 0. A hostname that contains a range pesudo-code and a port
# 1. A hostname that contains just a port
if hostname.count(":") > 1:
# Possible an IPv6 address, or maybe a host line with multiple ranges
# IPv6 with Port XXX:XXX::XXX.port
# FQDN foo.example.com
if hostname.count(".") == 1:
(hostname, port) = hostname.rsplit(".", 1)
elif ("[" in hostname and
"]" in hostname and
":" in hostname and
(hostname.rindex("]") < hostname.rindex(":")) or
("]" not in hostname and ":" in hostname)):
(hostname, port) = hostname.rsplit(":", 1)
hostnames = []
if detect_range(hostname):
hostnames = expand_hostname_range(hostname)
else:
hostnames = [hostname]
for hn in hostnames:
host = None
if hn in self.hosts:
host = self.hosts[hn]
else:
host = Host(name=hn, port=port)
self.hosts[hn] = host
if len(tokens) > 1:
for t in tokens[1:]:
if t.startswith('#'):
break
try:
(k,v) = t.split("=", 1)
except ValueError, e:
raise AnsibleError("Invalid ini entry in %s: %s - %s" % (self.filename, t, str(e)))
v = self._parse_value(v)
if k == 'ansible_ssh_host':
host.ipv4_address = v
host.set_variable(k, v)
self.groups[active_group_name].add_host(host)
# [southeast:children]
# atlanta
# raleigh
def _parse_group_children(self):
group = None
for line in self.lines:
line = line.strip()
if line is None or line == '':
continue
if line.startswith("[") and ":children]" in line:
line = line.replace("[","").replace(":children]","")
group = self.groups.get(line, None)
if group is None:
group = self.groups[line] = Group(name=line)
elif line.startswith("#") or line.startswith(";"):
pass
elif line.startswith("["):
group = None
elif group:
kid_group = self.groups.get(line, None)
if kid_group is None:
raise AnsibleError("child group is not defined: (%s)" % line)
else:
group.add_child_group(kid_group)
# [webservers:vars]
# http_port=1234
# maxRequestsPerChild=200
def _parse_group_variables(self):
group = None
for line in self.lines:
line = line.strip()
if line.startswith("[") and ":vars]" in line:
line = line.replace("[","").replace(":vars]","")
group = self.groups.get(line, None)
if group is None:
raise AnsibleError("can't add vars to undefined group: %s" % line)
elif line.startswith("#") or line.startswith(";"):
pass
elif line.startswith("["):
group = None
elif line == '':
pass
elif group:
if "=" not in line:
raise AnsibleError("variables assigned to group must be in key=value form")
else:
(k, v) = [e.strip() for e in line.split("=", 1)]
group.set_variable(k, self._parse_value(v))
def get_host_variables(self, host):
return {}
def _before_comment(self, msg):
''' what's the part of a string before a comment? '''
msg = msg.replace("\#","**NOT_A_COMMENT**")
msg = msg.split("#")[0]
msg = msg.replace("**NOT_A_COMMENT**","#")
return msg
def _compile_patterns(self):
'''
Compiles the regular expressions required to parse the inventory and
stores them in self.patterns.
'''
# Section names are square-bracketed expressions at the beginning of a
# line, comprising (1) a group name optionally followed by (2) a tag
# that specifies the contents of the section. We ignore any trailing
# whitespace and/or comments. For example:
#
# [groupname]
# [somegroup:vars]
# [naughty:children] # only get coal in their stockings
self.patterns['section'] = re.compile(
r'''^\[
([^:\]\s]+) # group name (see groupname below)
(?::(\w+))? # optional : and tag name
\]
\s* # ignore trailing whitespace
(?:\#.*)? # and/or a comment till the
$ # end of the line
''', re.X
)
# FIXME: What are the real restrictions on group names, or rather, what
# should they be? At the moment, they must be non-empty sequences of non
# whitespace characters excluding ':' and ']', but we should define more
# precise rules in order to support better diagnostics. The same applies
# to hostnames. It seems sensible for them both to follow DNS rules.
self.patterns['groupname'] = re.compile(
r'''^
([^:\]\s]+)
\s* # ignore trailing whitespace
(?:\#.*)? # and/or a comment till the
$ # end of the line
''', re.X
)
# The following patterns match the various ways in which a port number
# may be specified on an IPv6 address, IPv4 address, hostname, or host
# pattern. All of the above may be enclosed in square brackets with a
# mandatory :NN suffix; or all but the first may be given without any
# brackets but with an :NN suffix.
self.patterns['bracketed_hostport'] = re.compile(
r'''^
\[(.+)\] # [host identifier]
:([0-9]+) # :port number
$
''', re.X
)
self.patterns['hostport'] = re.compile(
r'''^
((?: # We want to match:
[^:\[\]] # (a non-range character
| # ...or...
\[[^\]]*\] # a complete bracketed expression)
)*) # repeated as many times as possible
:([0-9]+) # followed by a port number
$
''', re.X
)