import abc import copy from collections.abc import MutableMapping from ansible import constants as C from ansible.errors import AnsibleParserError, AnsibleRuntimeError, AnsibleError from ansible.inventory.helpers import get_group_vars from ansible.module_utils.six import string_types from ansible.module_utils.parsing.convert_bool import boolean from ansible.parsing.utils import addresses from ansible.plugins.inventory import BaseInventoryPlugin from ansible.utils.vars import isidentifier, combine_vars DOCUMENTATION = """ name: reconstructed short_description: A plugin that allows the dynamic construction of groups author: Emmanuel BENOÎT description: - This inventory plugin allows the construction of groups, the optional assignment of hosts to these groups and the computation of arbitrary facts. options: plugin: description: - Token that ensures this is a source file for the C(group_creator) plugin. required: True choices: ['tseeker.reconstructed.reconstructed','reconstructed'] instructions: description: - The list of instructions to be executed in order to generate the inventory parts. Each instruction is represented as a dictionnary with at least an C(action) field which determines which instruction must be executed. The instructions will be executed once for each inventory host. - Instructions may include various fields that act as control flow. - If the C(loop) field is present, it must contain a list (or a Jinja template that will return a list). The instruction will be repeated for each value in the list. The C(loop_var) field may be added to specify the name of the variable into which the current value will be written; by default the C(item) variable will be used. Once the loop execution ends, the loop variable's previous state is restored. - The C(when) field, if present, must contain a Jinja expression representing a condition which will be checked before the instruction is executed. - The C(run_once) field will ensure that the instuction it is attached to will only run one time at most. - The C(action) field must be set to one of the following values. - The C(block) action is another form of flow control, which can be used to repeat multiple instructions or make them obey a single conditional. The instruction must include a C(block) field, containing the list of instructions which are part of the block. In addition, it may have a C(rescue) field, containing a list of instructions which will be executed on error, and C(always), which may contain a list of instructions to execute in all cases. If the C(locals) field is defined, it must contain a table of local variables to define. Any local variable defined by the instructions under C(block), C(rescue) or C(always) will go out of scope once the block finishes executing, and the previous values, if any, will be restored. - C(create_group) creates a group. The name of the group must be provided using the C(group) field, which must be a valid name or a Jinja template that evaluates to a valid name. In addition, a C(parent) field containting the name of a single, existing parent group (or a Jinja template generating the name) may be provided. Finally, the C(add_host) field may be set to a truthy value if the current host must be added to the new group. - C(add_child) adds a child group to another group. The name of the group being added must be provided in the C(child) entry, while the name of the parent must be provided in the C(group) entry. Both groups must exist. In addition, the names may be specified using Jinja templates. - C(add_host) adds the current inventory host to a group. The name of the group must be provided in the C(group) entry. The group must exist. - C(fail) causes the computations for the current host to stop with an error. The error message may be specified in the C(message) entry; if present, it will be evaluated using Jinja. - C(set_fact) and C(set_var) create a fact and a local variable, respectively. Local variables will only be kept during the execution of the script for the current host, while facts will be added to the host's data. The C(name) entry specifies the name of the fact or variable while the C(value) entry specifies its value. Both may be Jinja templates. - C(stop) stops processing the list of instructions for the current host. - C(rename_host) changes a host's name. It can only be executed once per host. type: list elements: dict required: True strictness: description: - The C(host) setting will cause an error to skip the host being processed, and the C(full) setting will abort the execution altogether. required: False choices: ['host', 'full'] default: host """ INSTR_COMMON_FIELDS = ("action", "loop", "loop_var", "run_once", "vars", "when") """Fields that may be present on all instructions.""" INSTR_OWN_FIELDS = { "add_child": ("group", "child"), "add_host": ("group",), "block": ("block", "rescue", "always", "locals"), "create_group": ("group", "parent", "add_host"), "fail": ("msg",), "rename_host": ("name",), "set_fact": ("name", "value"), "set_var": ("name", "value"), "stop": (), } """Fields that are specific to each instruction.""" INSTR_FIELDS = {k: set(v + INSTR_COMMON_FIELDS) for k, v in INSTR_OWN_FIELDS.items()} """All supported fields for each instruction, including common and specific fields.""" class Context: """Script execution context. This class contains the script's context when it is executed for a given host. This includes the variable storage instance as well as the host's new name if a ``rename_host`` instruction has been executed. """ def __init__(self, host_vars): """Initialize the context. Args: host_vars: the host variables """ self.variables = VariableStorage(host_vars) self.new_name = None class VariableStorage(MutableMapping): """Variable storage and cache. This class implements storage for local variables, with the ability to save some of them and then restore them. It also implements a cache that combines both local variables and host facts. """ def __init__(self, host_vars): """Initialize the cache using the specified mapping of host variables. Args: host_vars: the host variables """ self._host_vars = host_vars self._script_vars = {} self._script_stack = [] self._cache = host_vars.copy() def _script_stack_push(self, variables): """Push the state of some local variables to the stack. This method will add a record containing the state of some variables to the stack so it may be restored later. The state for a single variable consists in a flag indicating whether the variable existed or not, and its value if it did. Args: variables: an iterable of variable names whose state must be pushed """ data = {} for v in variables: if v in self._script_vars: se = (True, copy.copy(self._script_vars[v])) else: se = (False, None) data[v] = se self._script_stack.append(data) def _script_stack_pop(self): """Restore the state of local variables from the stack. This method will restore state entries that were saved by :py:meth:`_script_stack_push`. Local variables that didn't exist then will be deleted, while variables which actually existed will be restored. The cache will be reset. """ restore = self._script_stack.pop() unchanged = 0 for vn, vv in restore.items(): existed, value = vv if existed: self._script_vars[vn] = value elif vn in self._script_vars: del self._script_vars[vn] else: unchanged += 1 if unchanged != len(restore): self._cache = self._host_vars.copy() self._cache.update(self._script_vars) def _set_host_var(self, name, value): """Set a host variable. This method sets the value of a host variable in the appropriate mapping, and updates the cache as will unless a local variable with the same name exists. Note: the actual inventory is not modified, only the local copy of host variables is. Args: name: the name of the variable value: the value of the variable """ self._host_vars[name] = value if name not in self._script_vars: self._cache[name] = value def __getitem__(self, k): return self._cache[k] def __setitem__(self, k, v): self._script_vars[k] = v self._cache[k] = v def __delitem__(self, k): del self._script_vars[k] if k in self._host_vars: self._cache[k] = self._host_vars[k] else: del self._cache[k] def __iter__(self): return self._cache.__iter__() def __len__(self): return len(self._cache) def keys(self): return self._cache.keys() def items(self): return self._cache.items() def values(self): return self._cache.values() class RcInstruction(abc.ABC): """An instruction that can be executed by the plugin.""" DEFAULT_LOOP_VAR = "item" """The name of the default loop variable.""" def __init__(self, inventory, templar, display, action): self._inventory = inventory self._templar = templar self._display = display self._action = action self._condition = None self._executed_once = None self._loop = None self._loop_var = None self._vars = {} self._save = None def __repr__(self): """Builds a compact debugging representation of the instruction, \ including any conditional or iteration clause.""" flow = [] if self._condition is not None: flow.append("when=%s" % (repr(self._condition),)) if self._loop is not None: flow.append( "loop=%s, loop_var=%s" % (repr(self._loop), repr(self._loop_var)) ) if len(self._vars) != 0: flow.append("vars=%s" % (repr(self._vars),)) if self._executed_once is not None: flow.append("run_once") if flow: output = "{%s}" % (", ".join(flow),) else: output = "" output += self.repr_instruction_only() return output def repr_instruction_only(self): """Builds a compact debugging representation of the instruction itself.""" return "%s()" % (self._action,) def dump(self): """Builds a representation of the instruction over multiple lines. This method generates a representation of the instruction, including any conditional or iteration clause, over multiple lines. It is meant to be used when generating a dump of the parsed program for high verbosity values. Returns: a list of strings (one for each line) """ output = [] if self._executed_once is not None: output.append("{run_once}") if self._loop is not None: output.append("{loop[%s]: %s}" % (self._loop_var, repr(self._loop))) for var in self._vars: output.append("{var %s=%s}" % (var, repr(self._vars[var]))) if self._condition is not None: output.append("{when: %s}" % (repr(self._condition),)) output.extend(self.dump_instruction()) return output def dump_instruction(self): """Builds the multi-line debugging representation of the instruction. This method returns a list of strings that correspond to the output lines that represent the instruction. Returns: a list of strings (one for each line) """ return [self.repr_instruction_only()] def parse(self, record): """Parse the instruction's record. This method ensures that no unsupported fields are present in the instruction's record. It then extracts the conditional clause and the iteration clause, if they are present. Finally it calls ``parse_action`` in order to extract the instruction itself. Args: record: the dictionnary that contains the instruction """ assert "action" in record and record["action"] == self._action # Ensure there are no unsupported fields extra_fields = set(record.keys()).difference(INSTR_FIELDS[self._action]) if extra_fields: raise AnsibleParserError( "%s: unsupported fields: %s" % (self._action, ", ".join(extra_fields)) ) # Extract the loop, condition and local variable clauses self.parse_condition(record) self.parse_loop(record) self._vars = self.parse_vars(record) self.parse_run_once(record) # Cache the list of variables to save before execution save = list(self._vars.keys()) if self._loop is not None: save.append(self._loop_var) self._save = tuple(save) # Process action-specific fields self.parse_action(record) def parse_condition(self, record): """Parse the ``when`` clause of an instruction. If the ``when`` clause is present, ensure it contains a string then store it. Args: record: the YAML data Raises: AnsibleParserError: if the ``when`` clause is present but does not \ contain a string """ if "when" not in record: return if not isinstance(record["when"], string_types): raise AnsibleParserError( "%s: 'when' clause is not a string" % (self._action,) ) self._condition = record["when"] def parse_loop(self, record): """Parse the ``loop`` and ``loop_var`` clauses of an instruction. Check for proper usage of both the ``loop`` and ``loop_var`` clauses, then extract the values and store them. Args: record: the instruction's YAML data Raises: AnsibleParserError: when ``loop_var`` is being used without \ ``loop``, when the type of either is incorrect, or when the \ value of ``loop_var`` is not a valid identifier. """ if "loop" not in record: if "loop_var" in record: raise AnsibleParserError( "%s: 'loop_var' clause found without 'loop'" % (self._action,) ) return loop = record["loop"] if not isinstance(loop, string_types + (list,)): raise AnsibleParserError( "%s: 'loop' clause is neither a string nor a list" % (self._action,) ) loop_var = record.get("loop_var", RcInstruction.DEFAULT_LOOP_VAR) if not isinstance(loop_var, string_types): raise AnsibleParserError( "%s: 'loop_var' clause is not a string" % (self._action,) ) if not isidentifier(loop_var): raise AnsibleParserError( "%s: 'loop_var' value '%s' is not a valid identifier" % (self._action, loop_var) ) self._loop = loop self._loop_var = loop_var def parse_vars(self, record): """Parse local variable definitions from the record. This method checks for a ``vars`` section in the YAML data, and extracts it if it exists. Args: record: the YAML data for the instruction Returns: a dictionnary that contains the variable definitions Raises: AnsibleParserError: when the ``vars`` entry is invalid or contains \ invalid definitions """ if "vars" not in record: return {} if not isinstance(record["vars"], dict): raise AnsibleParserError( "%s: 'vars' should be a dictionnary" % (self._action,) ) for k, v in record["vars"].items(): if not isinstance(k, string_types): raise AnsibleParserError( "%s: vars identifiers must be strings" % (self._action,) ) if not isidentifier(k): raise AnsibleParserError( "%s: '%s' is not a valid identifier" % (self._action, k) ) return record["vars"] def parse_run_once(self, record): """Parse an instruction's ``run_once`` clause. Args: record: the YAML data for the instruction Raises: AnsibleParserError: when the clause is present but does not \ contain a truthy value """ if "run_once" not in record: return if not isinstance(record["run_once"], bool): raise AnsibleParserError( "%s: run_once must be a truthy value" % (self._action,) ) if record["run_once"]: self._executed_once = False def parse_group_name(self, record, name): """Parse a field containing the name of a group, or a template. This helper method may be used by implementations to extract either a group name or a template from a field. If the string cannot possibly be a Jinja template, it will be stripped of extra spaces then checked for invalid characters. Args: record: the dictionnary that contains the instruction name: the name of the field to read Returns: a tuple consisting of a boolean that indicates whether the string may be a template or not, and the string itself. """ if name not in record: raise AnsibleParserError("%s: missing '%s' field" % (self._action, name)) group = record[name] if not isinstance(group, string_types): raise AnsibleParserError( "%s: '%s' field must be a string" % (self._action, name) ) may_be_template = self._templar.is_possibly_template(group) if not may_be_template: group = group.strip() if C.INVALID_VARIABLE_NAMES.findall(group): raise AnsibleParserError( "%s: invalid group name '%s' in field '%s'" % (self._action, group, name) ) return may_be_template, group @abc.abstractmethod def parse_action(self, record): """Parse the instruction-specific fields. This method must be overridden to read all necessary data from the input record and configure the instruction. Args: record: the dictionnary that contains the instruction """ raise NotImplementedError def run_for(self, host_name, context): """Execute the instruction for a given host. This method is the entry point for instruction execution. Depending on whether an iteration clause is present or not, it will either call :py:meth:`run_iteration` directly or evaluate the loop data then run it once for each item, after setting the loop variable. Args: host_name: the name of the host to execute the instruction for context: the execution context Returns: ``True`` if execution must continue, ``False`` if it must be interrupted """ if self._executed_once is True: return True if self._executed_once is False: self._executed_once = True # Save previous loop and local variables state context.variables._script_stack_push(self._save) try: # Instructions without loops if self._loop is None: self._display.vvvv("%s : running action %s" % (host_name, self._action)) return self.run_iteration(host_name, context) # Loop over all values for value in self.evaluate_loop(host_name, context.variables): self._display.vvvv( "%s : running action %s for item %s" % (host_name, self._action, repr(value)) ) context.variables[self._loop_var] = value if not self.run_iteration(host_name, context): return False return True finally: # Restore loop variable state context.variables._script_stack_pop() def run_iteration(self, host_name, context): """Check the condition if it exists, then run the instruction. Args: host_name: the name of the host to execute the instruction for context: the execution context Returns: ``True`` if execution must continue, ``False`` if it must be interrupted """ self.compute_locals(context.variables) if self.evaluate_condition(host_name, context.variables): rv = self.execute_action(host_name, context) if not rv: self._display.vvvvv( "%s : action %s returned False, stopping" % (host_name, self._action) ) else: rv = True return rv def evaluate_condition(self, host_name, variables): """Evaluate the condition for an instruction's execution. Args: host_name: the name of the host to execute the instruction for variables: the variable storage instance Returns: ``True`` if there is no conditional clause for this instruction, or if there is one and it evaluated to a truthy value; ``False`` otherwise. """ if self._condition is None: return True t = self._templar t.available_variables = variables template = "%s%s%s" % ( t.environment.variable_start_string, self._condition, t.environment.variable_end_string, ) rv = boolean(t.template(template, disable_lookups=False)) self._display.vvvvv( "host %s, action %s, condition %s evaluating to %s" % (host_name, self._action, repr(self._condition), repr(rv)) ) return rv def compute_locals(self, variables): """Compute local variables. This method iterates through all local variable definitions and runs them through the templar. Args: variables: the variable storage instance """ self._templar.available_variables = variables for key, value in self._vars.items(): result = self._templar.template(value) variables[key] = result self._display.vvvv("- set local variable %s to %s" % (key, result)) def evaluate_loop(self, host_name, variables): """Evaluate the values to iterate over when a ``loop`` is defined. Args: host_name: the name of the host to execute the instruction for variables: the variable storage instance Returns: the list of items to iterate over """ self._display.vvvvv( "host %s, action %s, evaluating loop template %s" % (host_name, self._action, repr(self._loop)) ) self._templar.available_variables = variables value = self._templar.template(self._loop, disable_lookups=False) if not isinstance(value, list): raise AnsibleRuntimeError( "template '%s' did not evaluate to a list" % (self._loop,) ) return value def get_templated_group(self, variables, may_be_template, name, must_exist=False): """Extract a group name from its source, optionally ensure it exists, \ then return it. Args: variables: the variable storage instance may_be_template: a flag that indicates whether the name should be \ processed with the templar. name: the name or its template must_exist: a flag that, if ``True``, will cause an exception to \ be raised if the group does not exist. Returns: the name of the group """ if may_be_template: self._templar.available_variables = variables real_name = self._templar.template(name) if not isinstance(real_name, string_types): raise AnsibleRuntimeError( "%s: '%s' did not coalesce into a string" % (self._action, name) ) real_name = real_name.strip() if C.INVALID_VARIABLE_NAMES.findall(real_name): raise AnsibleRuntimeError( "%s: '%s' is not a valid group name" % (self._action, real_name) ) else: real_name = name if must_exist and real_name not in self._inventory.groups: raise AnsibleRuntimeError( "%s: group '%s' does not exist" % (self._action, real_name) ) return real_name @abc.abstractmethod def execute_action(self, host_name, context): """Execute the instruction. This method must be overridden to implement the actual action of the instruction. Args: host_name: the name of the host to execute the instruction for context: the execution context for the current host Return: ``True`` if the script's execution should continue, ``False`` if it should be interrupted. """ raise NotImplementedError class RciCreateGroup(RcInstruction): """``create_group`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "create_group") self._group_mbt = None self._group_name = None self._parent_mbt = None self._parent_name = None self._add_host = None def repr_instruction_only(self): output = "%s(group=%s" % (self._action, repr(self._group_name)) if self._parent_name is not None: output += ",parent=" + repr(self._parent_name) output += ",add_host=" + repr(self._add_host) + ")" return output def parse_action(self, record): assert self._group_mbt is None and self._group_name is None assert self._parent_mbt is None and self._parent_name is None assert self._add_host is None self._add_host = record.get("add_host", False) self._group_mbt, self._group_name = self.parse_group_name(record, "group") if "parent" in record: self._parent_mbt, self._parent_name = self.parse_group_name( record, "parent" ) def execute_action(self, host_name, context): assert not ( self._group_mbt is None or self._group_name is None or self._add_host is None ) if self._parent_name is not None: parent = self.get_templated_group( context.variables, self._parent_mbt, self._parent_name, must_exist=True ) name = self.get_templated_group( context.variables, self._group_mbt, self._group_name ) self._inventory.add_group(name) self._display.vvv("- created group %s" % (name,)) if self._parent_name is not None: self._inventory.add_child(parent, name) self._display.vvv("- added group %s to %s" % (name, parent)) if self._add_host: self._inventory.add_child(name, host_name) self._display.vvv("- added host %s to %s" % (host_name, name)) return True class RciAddHost(RcInstruction): """``add_host`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "add_host") self._may_be_template = None self._group = None def repr_instruction_only(self): return "%s(group=%s)" % (self._action, repr(self._group)) def parse_action(self, record): assert self._may_be_template is None and self._group is None self._may_be_template, self._group = self.parse_group_name(record, "group") def execute_action(self, host_name, context): assert not (self._may_be_template is None or self._group is None) name = self.get_templated_group( context.variables, self._may_be_template, self._group, must_exist=True ) self._inventory.add_child(name, host_name) self._display.vvv("- added host %s to %s" % (host_name, name)) return True class RciAddChild(RcInstruction): """``add_child`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "add_child") self._group_mbt = None self._group_name = None self._child_mbt = None self._child_name = None def repr_instruction_only(self): return "%s(group=%s, child=%s)" % ( self._action, repr(self._group_name), repr(self._child_name), ) def parse_action(self, record): assert self._group_mbt is None and self._group_name is None assert self._child_mbt is None and self._child_name is None self._group_mbt, self._group_name = self.parse_group_name(record, "group") self._child_mbt, self._child_name = self.parse_group_name(record, "child") def execute_action(self, host_name, context): assert not (self._group_mbt is None or self._group_name is None) assert not (self._child_mbt is None or self._child_name is None) group = self.get_templated_group( context.variables, self._group_mbt, self._group_name, must_exist=True ) child = self.get_templated_group( context.variables, self._child_mbt, self._child_name, must_exist=True ) self._inventory.add_child(group, child) self._display.vvv("- added group %s to %s" % (child, group)) return True class RciSetVarOrFact(RcInstruction): """Implementation of the ``set_fact`` and ``set_var`` instructions.""" def __init__(self, inventory, templar, display, is_fact): action = "set_" + ("fact" if is_fact else "var") super().__init__(inventory, templar, display, action) self._is_fact = is_fact self._var_name = None self._name_may_be_template = None self._var_value = None def repr_instruction_only(self): return "%s(name=%s, value=%s)" % ( self._action, repr(self._var_name), repr(self._var_value), ) def parse_action(self, record): assert ( self._var_name is None and self._name_may_be_template is None and self._var_value is None ) if "name" not in record: raise AnsibleParserError("%s: missing 'name' field" % (self._action,)) name = record["name"] if not isinstance(name, string_types): raise AnsibleParserError("%s: 'name' must be a string" % (self._action,)) if "value" not in record: raise AnsibleParserError("%s: missing 'value' field" % (self._action,)) nmbt = self._templar.is_possibly_template(name) if not (nmbt or isidentifier(name)): raise AnsibleParserError( "%s: '%s' is not a valid variable name" % (self._action, name) ) self._name_may_be_template = nmbt self._var_name = name self._var_value = record["value"] def execute_action(self, host_name, context): assert not ( self._var_name is None or self._name_may_be_template is None or self._var_value is None ) self._templar.available_variables = context.variables if self._name_may_be_template: name = self._templar.template(self._var_name) if not isinstance(name, string_types): raise AnsibleRuntimeError( "%s: '%s' did not coalesce into a string" % (self._action, self._var_name) ) if not isidentifier(name): raise AnsibleRuntimeError( "%s: '%s' is not a valid variable name" % (self._action, name) ) else: name = self._var_name value = self._templar.template(self._var_value) if self._is_fact: self._inventory.set_variable(host_name, name, value) context.variables._set_host_var(name, value) else: context.variables[name] = value self._display.vvv( "- set %s %s to %s" % ("fact" if self._is_fact else "var", name, repr(value)) ) return True class RciStop(RcInstruction): """``stop`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "stop") def parse_action(self, record): pass def execute_action(self, host_name, context): self._display.vvv("- stopped execution") return False class RciFail(RcInstruction): """``fail`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "fail") self._message = None def repr_instruction_only(self): if self._message is None: return "%s()" % (self._action,) else: return "%s(%s)" % (self._action, self._message) def parse_action(self, record): self._message = record.get("msg", None) def execute_action(self, host_name, context): if self._message is None: message = "fail requested (%s)" % (host_name,) else: self._templar.available_variables = context.variables message = self._templar.template(self._message) self._display.vvv("- failed with message %s" % (message,)) raise AnsibleRuntimeError(message) class RciRenameHost(RcInstruction): """``rename_host`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "rename_host") self._name = None self._name_may_be_template = None def parse_action(self, record): assert self._name is None and self._name_may_be_template is None if "name" not in record: raise AnsibleParserError("%s: missing 'name' field" % (self._action,)) name = record["name"] if not isinstance(name, string_types): raise AnsibleParserError("%s: 'name' must be a string" % (self._action,)) nmbt = self._templar.is_possibly_template(name) if not (nmbt or addresses.patterns['hostname'].match(name)): raise AnsibleParserError( "%s: '%s' is not a valid host name" % (self._action, name) ) self._name_may_be_template = nmbt self._name = name def execute_action(self, host_name, context): if context.new_name is not None: raise AnsibleRuntimeError("Host has already been renamed") if self._name_may_be_template: self._templar.available_variables = context.variables name = self._templar.template(self._name) if not addresses.patterns['hostname'].match(name): raise AnsibleRuntimeError( "%s: '%s' is not a valid host name" % (self._action, name) ) else: name = self._name self._display.vvv("- renaming host %s to %s" % (host_name, name)) context.new_name = name return True class RciBlock(RcInstruction): """``block`` instruction implementation.""" def __init__(self, inventory, templar, display): super().__init__(inventory, templar, display, "block") self._block = None self._rescue = None self._always = None def repr_instruction_only(self): return "%s(block=%s, rescue=%s, always=%s)" % ( self._action, repr(self._block), repr(self._rescue), repr(self._always), ) def dump_instruction(self): output = ["%s(...):" % (self._action,)] self.dump_section(output, "block", self._block) self.dump_section(output, "rescue", self._rescue) self.dump_section(output, "always", self._always) return output def dump_section(self, output, section_name, section_contents): """Dump one of the sections. This method is used to create the dump that corresponds to one of the ``block``, ``rescue`` or ``always`` lists of instructions. Args: output: a list of strings to append to block_name: the name of the section being dumped block_contents: the list of instructions in this section """ if not section_contents: return output.append(" " + section_name + ":") for pos, instr in enumerate(section_contents): if pos != 0: output.append("") output.extend(" " + s for s in instr.dump()) def parse_action(self, record): assert self._block is None and self._rescue is None and self._always is None if "block" not in record: raise AnsibleParserError("%s: missing 'block' field" % (self._action,)) self._block = self.parse_block(record, "block") if "rescue" in record: self._rescue = self.parse_block(record, "rescue") else: self._rescue = [] if "always" in record: self._always = self.parse_block(record, "always") else: self._always = [] def parse_block(self, record, key): """Parse the contents of one of the instruction lists. This method will extract the instructions for one of the ``block``, ``rescue`` and ``always`` sections. The corresponding key must exist in the YAML data when the method is called. It will ensure that it is a list before reading the instructions it contains. Args: record: the record of the ``block`` instruction key: the section to read (``block``, ``rescue`` or ``always``) Returns: the list of instructions in the section. """ if not isinstance(record[key], list): raise AnsibleParserError( "%s: '%s' field must contain a list of instructions" % (self._action, key) ) instructions = [] for record in record[key]: instructions.append( parse_instruction(self._inventory, self._templar, self._display, record) ) return instructions def execute_action(self, host_name, context): assert not (self._block is None or self._rescue is None or self._always is None) try: try: self._display.vvv("- running 'block' instructions") return self.run_section(self._block, host_name, context) except AnsibleError as e: if not self._rescue: self._display.vvv("- block failed") raise self._display.vvv("- block failed, running 'rescue' instructions") context.variables["reconstructed_error"] = str(e) return self.run_section(self._rescue, host_name, context) finally: self._display.vvv("- block exited, running 'always' instructions") self.run_section(self._always, host_name, context) def run_section(self, section, host_name, context): """Execute a single section. This method executes the sequence of instructions in a single section. Args: section: the list of instructions host_name: the name of the host being processed context: the execution context for the current host Returns: ``True`` if the script's execution should continue, ``False`` if it should be interrupted """ for instruction in section: if not instruction.run_for(host_name, context): return False return True INSTRUCTIONS = { "add_child": RciAddChild, "add_host": RciAddHost, "block": RciBlock, "create_group": RciCreateGroup, "fail": RciFail, "rename_host": RciRenameHost, "set_fact": lambda i, t, d: RciSetVarOrFact(i, t, d, True), "set_var": lambda i, t, d: RciSetVarOrFact(i, t, d, False), "stop": RciStop, } def parse_instruction(inventory, templar, display, record): action = record["action"] if action not in INSTRUCTIONS: raise AnsibleParserError("Unknown action '%s'" % (action,)) instruction = INSTRUCTIONS[action](inventory, templar, display) instruction.parse(record) return instruction class InventoryModule(BaseInventoryPlugin): """Constructs groups based on lists of instructions.""" NAME = "tseeker.reconstructed.reconstructed" def verify_file(self, path): return super().verify_file(path) and path.endswith((".yaml", ".yml")) def parse(self, inventory, loader, path, cache=True): super().parse(inventory, loader, path, cache) self._read_config_data(path) # Read the program instr_src = self.get_option("instructions") instructions = [] for record in instr_src: instructions.append( parse_instruction(self.inventory, self.templar, self.display, record) ) self.dump_program(instructions) # Execute it for each host rename = [] for host in inventory.hosts: self.display.vvv("executing reconstructed script for %s" % (host,)) try: new_name = self.exec_for_host(host, instructions) except AnsibleError as e: if self.get_option("strictness") == "full": raise self.display.warning( "reconstructed - error on host %s: %s" % (host, repr(e)) ) continue if new_name is not None: rename.append((host, new_name)) # Rename hosts for old_name, new_name in rename: if old_name.lower() == new_name.lower(): continue self.rename_host(old_name, new_name) def exec_for_host(self, host, instructions): """Execute the program for a single host. This method initialises a variable storage instance from the host's variables then runs the instructions. Args: host: the name of the host to execute for instructions: the list of instructions to execute """ host_obj = self.inventory.get_host(host) host_vars = host_obj.get_vars() host_groups = host_obj.get_groups().copy() if not any(g.name == "all" for g in host_groups): host_groups.append(self.inventory.groups["all"]) group_vars = get_group_vars(host_groups) context = Context(combine_vars(group_vars, host_vars)) for instruction in instructions: if not instruction.run_for(host, context): break return context.new_name def dump_program(self, instructions): """Dump the whole program to the log, depending on verbosity level. This method will dump the program to the log. If verbosity is at level 3, the dump will be written using `repr`. If it is 4 or higher, it will be dumped in a much more readable, albeit longer, form. Args: instructions: the list of instructions in the program """ if self.display.verbosity < 4: if self.display.verbosity == 3: self.display.vvv("parsed program: " + repr(instructions)) return output = [] for pos, instr in enumerate(instructions): if pos: output.append("") output.extend(instr.dump()) self.display.vvvv("parsed program:\n\n" + "\n".join(" " + s for s in output)) def rename_host(self, old_name, new_name): """Renames a host. This method "renames" a host by removing the host's current inventory record and creating a new one with the same data, except for the name. Args: old_name: the host's old name new_name: the host's new name """ if self.inventory.get_host(new_name) is not None: raise AnsibleRuntimeError("duplicate host name %s" % (new_name,)) self.display.vvv("renaming host %s to %s" % (old_name, new_name)) host = self.inventory.get_host(old_name) group_names = [] for g in host.get_groups(): if g.name == 'all': continue if old_name in g.host_names: group_names.append(g.name) self.inventory.remove_host(host) self.inventory.add_host(new_name) new_host = self.inventory.get_host(new_name) new_host._uuid = host._uuid if host.address == host.name: new_host.address = new_name new_host.vars = host.vars for group in group_names: self.inventory.add_child(group, new_name)