Ansible源码解析Inventory总管概念__init__.py

hongleimi

class Inventory(object):　　"""
　　Host inventory for ansible.
　　"""
　　__slots__ = [ 'host_list', 'groups', '_restriction', '_also_restriction', '_subset',
　　'parser', '_vars_per_host', '_vars_per_group', '_hosts_cache', '_groups_list',
　　'_pattern_cache', '_vault_password', '_vars_plugins', '_playbook_basedir']
　　def __init__(self, host_list=C.DEFAULT_HOST_LIST, vault_password=None):
　　# the host file file, or script path, or list of hosts
　　# if a list, inventory data will NOT be loaded
　　# 就是这个host_list非常关键，我们要获取inventory按照格式给一个script就行
　　# 注意加载中文的时候加一个.decode("utf-8")
　　self.host_list = host_list
　　self._vault_password=vault_password
　　# caching to avoid repeated calculations, particularly with
　　# external inventory scripts.
　　# 这里做一些缓存，避免重复计算，但是指同一个实例。
　　self._vars_per_host  = {}
　　self._vars_per_group = {}
　　self._hosts_cache    = {}
　　self._groups_list    = {}
　　self._pattern_cache  = {}
　　# to be set by calling set_playbook_basedir by playbook code
　　self._playbook_basedir = None
　　# the inventory object holds a list of groups
　　self.groups = []
　　# a list of host(names) to contain current inquiries to
　　self._restriction = None
　　self._also_restriction = None
　　self._subset = None
　　# 条件1，如果是字符串并且,在字符串中，进行赋值
　　# 注意这个if与下面的if不是一个逻辑，这是先行逻辑
　　if isinstance(host_list, basestring):
　　if "," in host_list:
　　host_list = host_list.split(",")
　　host_list = [ h for h in host_list if h and h.strip() ]
　　# 注意这里会输出一个列表
　　if host_list is None:
　　self.parser = None
　　# 接着上面的处理， 匹配IPV6,使用host类实例化主机名然后添加主机
　　elif isinstance(host_list, list):
　　self.parser = None
　　all = Group('all')
　　self.groups = [ all ]
　　ipv6_re = re.compile('\[([a-f:A-F0-9]*[%[0-z]+]?)\](?::(\d+))?')
　　for x in host_list:
　　m = ipv6_re.match(x)
　　if m:
　　all.add_host(Host(m.groups()[0], m.groups()[1]))
　　else:
　　if ":" in x:
　　tokens = x.rsplit(":", 1)
　　# if there is ':' in the address, then this is an ipv6
　　if ':' in tokens[0]:
　　all.add_host(Host(x))
　　else:
　　all.add_host(Host(tokens[0], tokens[1]))
　　else:
　　all.add_host(Host(x))
　　# 如果这个文件名存在，即走文件名方式，判断是否是目录，是目录调dir解析
　　# 是文件就是脚本解析，即我们讲的动态inventory，走不通这个就走ini配置文件解析
　　# 这里的判断点就是SheBang(#!)
　　elif os.path.exists(host_list):
　　if os.path.isdir(host_list):
　　# Ensure basedir is inside the directory
　　self.host_list = os.path.join(self.host_list, "")
　　self.parser = InventoryDirectory(filename=host_list) # 目录解析
　　self.groups = self.parser.groups.values()
　　else: # 动态inventory
　　# check to see if the specified file starts with a
　　# shebang (#!/), so if an error is raised by the parser

　　#>　　shebang_present = False
　　try:
　　inv_file = open(host_list)
　　first_line = inv_file.readlines()[0]
　　inv_file.close()
　　if first_line.startswith('#!'):
　　shebang_present = True
　　except:
　　pass
　　if utils.is_executable(host_list):
　　try:
　　self.parser = InventoryScript(filename=host_list) # 脚本解析
　　self.groups = self.parser.groups.values()
　　except:
　　if not shebang_present:
　　raise errors.AnsibleError("The file %s is marked as executable, but failed to execute correctly. " % host_list + \
　　"If this is not supposed to be an executable script, correct this with `chmod -x %s`." % host_list)
　　else:
　　raise
　　else:
　　try:
　　self.parser = InventoryParser(filename=host_list) # 文件解析
　　self.groups = self.parser.groups.values()
　　except:
　　if shebang_present:
　　raise errors.AnsibleError("The file %s looks like it should be an executable inventory script, but is not marked executable. " % host_list + \
　　"Perhaps you want to correct this with `chmod +x %s`?" % host_list)
　　else:
　　raise
　　utils.plugins.vars_loader.add_directory(self.basedir(), with_subdir=True)
　　else:
　　raise errors.AnsibleError("Unable to find an inventory file, specify one with -i ?")
　　self._vars_plugins = [ x for x in utils.plugins.vars_loader.all(self) ]
　　# get group vars from group_vars/ files and vars plugins
　　for group in self.groups:
　　group.vars = utils.combine_vars(group.vars, self.get_group_variables(group.name, vault_password=self._vault_password))
　　# get host vars from host_vars/ files and vars plugins
　　for host in self.get_hosts():
　　host.vars = utils.combine_vars(host.vars, self.get_host_variables(host.name, vault_password=self._vault_password))