Files
dbt-core/core/dbt/parser/models.py

569 lines
23 KiB
Python

# New for Python models :p
import ast
import random
from copy import deepcopy
from functools import reduce
from itertools import chain
from typing import Any, Dict, Iterator, List, Optional, Tuple, Union
import dbt.tracking as tracking
from dbt import utils
from dbt.artifacts.resources import RefArgs
from dbt.clients.jinja import get_rendered
from dbt.context.context_config import ContextConfig
from dbt.contracts.graph.nodes import ModelNode
from dbt.exceptions import (
ModelConfigError,
ParsingError,
PythonLiteralEvalError,
PythonParsingError,
)
from dbt.flags import get_flags
from dbt.node_types import ModelLanguage, NodeType
from dbt.parser.base import SimpleSQLParser
from dbt.parser.search import FileBlock
from dbt_common.dataclass_schema import ValidationError
from dbt_common.exceptions.macros import UndefinedMacroError
from dbt_extractor import ExtractionError, py_extract_from_source # type: ignore
dbt_function_key_words = set(["ref", "source", "config", "get"])
dbt_function_full_names = set(["dbt.ref", "dbt.source", "dbt.config", "dbt.config.get"])
class PythonValidationVisitor(ast.NodeVisitor):
def __init__(self) -> None:
super().__init__()
self.dbt_errors: List[str] = []
self.num_model_def = 0
def visit_FunctionDef(self, node: ast.FunctionDef) -> None:
if node.name == "model":
self.num_model_def += 1
if node.args.args and not node.args.args[0].arg == "dbt":
self.dbt_errors.append("'dbt' not provided for model as the first argument")
if len(node.args.args) != 2:
self.dbt_errors.append(
"model function should have two args, `dbt` and a session to current warehouse"
)
# check we have a return and only one
if not isinstance(node.body[-1], ast.Return) or isinstance(
node.body[-1].value, ast.Tuple
):
self.dbt_errors.append(
"In current version, model function should return only one dataframe object"
)
def check_error(self, node):
if self.num_model_def != 1:
raise ParsingError(
f"dbt allows exactly one model defined per python file, found {self.num_model_def}",
node=node,
)
if len(self.dbt_errors) != 0:
raise ParsingError("\n".join(self.dbt_errors), node=node)
class PythonParseVisitor(ast.NodeVisitor):
def __init__(self, dbt_node):
super().__init__()
self.dbt_node = dbt_node
self.dbt_function_calls = []
self.packages = []
@classmethod
def _flatten_attr(cls, node):
if isinstance(node, ast.Attribute):
return str(cls._flatten_attr(node.value)) + "." + node.attr
elif isinstance(node, ast.Name):
return str(node.id)
else:
pass
def _safe_eval(self, node):
try:
return ast.literal_eval(node)
except (SyntaxError, ValueError, TypeError, MemoryError, RecursionError) as exc:
raise PythonLiteralEvalError(exc, node=self.dbt_node) from exc
def _get_call_literals(self, node):
# List of literals
arg_literals = []
kwarg_literals = {}
# TODO : Make sure this throws (and that we catch it)
# for non-literal inputs
for arg in node.args:
rendered = self._safe_eval(arg)
arg_literals.append(rendered)
for keyword in node.keywords:
key = keyword.arg
rendered = self._safe_eval(keyword.value)
kwarg_literals[key] = rendered
return arg_literals, kwarg_literals
def visit_Call(self, node: ast.Call) -> None:
# check weather the current call could be a dbt function call
if isinstance(node.func, ast.Attribute) and node.func.attr in dbt_function_key_words:
func_name = self._flatten_attr(node.func)
# check weather the current call really is a dbt function call
if func_name in dbt_function_full_names:
# drop the dot-dbt prefix
func_name = func_name.split(".")[-1]
args, kwargs = self._get_call_literals(node)
self.dbt_function_calls.append((func_name, args, kwargs))
# no matter what happened above, we should keep visiting the rest of the tree
# visit args and kwargs to see if there's call in it
for obj in node.args + [kwarg.value for kwarg in node.keywords]:
if isinstance(obj, ast.Call):
self.visit_Call(obj)
# support dbt.ref in list args, kwargs
elif isinstance(obj, ast.List) or isinstance(obj, ast.Tuple):
for el in obj.elts:
if isinstance(el, ast.Call):
self.visit_Call(el)
# support dbt.ref in dict args, kwargs
elif isinstance(obj, ast.Dict):
for value in obj.values:
if isinstance(value, ast.Call):
self.visit_Call(value)
# support dbt function calls in f-strings
elif isinstance(obj, ast.JoinedStr):
for value in obj.values:
if isinstance(value, ast.FormattedValue) and isinstance(value.value, ast.Call):
self.visit_Call(value.value)
# visit node.func.value if we are at an call attr
if isinstance(node.func, ast.Attribute):
self.attribute_helper(node.func)
def attribute_helper(self, node: ast.Attribute) -> None:
while isinstance(node, ast.Attribute):
node = node.value # type: ignore
if isinstance(node, ast.Call):
self.visit_Call(node)
def visit_Import(self, node: ast.Import) -> None:
for n in node.names:
self.packages.append(n.name.split(".")[0])
def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
if node.module:
self.packages.append(node.module.split(".")[0])
def verify_python_model_code(node):
# TODO: add a test for this
try:
rendered_python = get_rendered(
node.raw_code,
{},
node,
)
if rendered_python != node.raw_code:
raise ParsingError("")
except (UndefinedMacroError, ParsingError):
raise ParsingError("No jinja in python model code is allowed", node=node)
class ModelParser(SimpleSQLParser[ModelNode]):
def parse_from_dict(self, dct, validate=True) -> ModelNode:
if validate:
ModelNode.validate(dct)
return ModelNode.from_dict(dct)
@property
def resource_type(self) -> NodeType:
return NodeType.Model
@classmethod
def get_compiled_path(cls, block: FileBlock):
return block.path.relative_path
def parse_python_model(self, node, config, context):
config_keys_used = []
config_keys_defaults = []
try:
tree = ast.parse(node.raw_code, filename=node.original_file_path)
except SyntaxError as exc:
raise PythonParsingError(exc, node=node) from exc
# Only parse if AST tree has instructions in body
if tree.body:
# We are doing a validator and a parser because visit_FunctionDef in parser
# would actually make the parser not doing the visit_Calls any more
dbt_validator = PythonValidationVisitor()
dbt_validator.visit(tree)
dbt_validator.check_error(node)
dbt_parser = PythonParseVisitor(node)
dbt_parser.visit(tree)
for func, args, kwargs in dbt_parser.dbt_function_calls:
if func == "get":
num_args = len(args)
if num_args == 0:
raise ParsingError(
"dbt.config.get() requires at least one argument",
node=node,
)
if num_args > 2:
raise ParsingError(
f"dbt.config.get() takes at most 2 arguments ({num_args} given)",
node=node,
)
key = args[0]
default_value = args[1] if num_args == 2 else None
config_keys_used.append(key)
config_keys_defaults.append(default_value)
continue
context[func](*args, **kwargs)
if config_keys_used:
# this is being used in macro build_config_dict
context["config"](
config_keys_used=config_keys_used,
config_keys_defaults=config_keys_defaults,
)
def render_update(self, node: ModelNode, config: ContextConfig) -> None:
self.manifest._parsing_info.static_analysis_path_count += 1
flags = get_flags()
if node.language == ModelLanguage.python:
try:
verify_python_model_code(node)
context = self._context_for(node, config)
self.parse_python_model(node, config, context)
self.update_parsed_node_config(node, config, context=context)
except ValidationError as exc:
# we got a ValidationError - probably bad types in config()
raise ModelConfigError(exc, node=node) from exc
return
elif not flags.STATIC_PARSER:
# jinja rendering
super().render_update(node, config)
return
# only sample for experimental parser correctness on normal runs,
# not when the experimental parser flag is on.
exp_sample: bool = False
# sampling the stable static parser against jinja is significantly
# more expensive and therefore done far less frequently.
stable_sample: bool = False
# there are two samples above, and it is perfectly fine if both happen
# at the same time. If that happens, the experimental parser, stable
# parser, and jinja rendering will run on the same model file and
# send back codes for experimental v stable, and stable v jinja.
if not flags.USE_EXPERIMENTAL_PARSER:
# `True` roughly 1/5000 times this function is called
# sample = random.randint(1, 5001) == 5000
stable_sample = random.randint(1, 5001) == 5000
# sampling the experimental parser is explicitly disabled here, but use the following
# commented code to sample a fraction of the time when new
# experimental features are added.
# `True` roughly 1/100 times this function is called
# exp_sample = random.randint(1, 101) == 100
# top-level declaration of variables
statically_parsed: Optional[Union[str, Dict[str, List[Any]]]] = None
experimental_sample: Optional[Union[str, Dict[str, List[Any]]]] = None
exp_sample_node: Optional[ModelNode] = None
exp_sample_config: Optional[ContextConfig] = None
jinja_sample_node: Optional[ModelNode] = None
jinja_sample_config: Optional[ContextConfig] = None
result: List[str] = []
# sample the experimental parser only during a normal run
if exp_sample and not flags.USE_EXPERIMENTAL_PARSER:
experimental_sample = self.run_experimental_parser(node)
# if the experimental parser succeeded, make a full copy of model parser
# and populate _everything_ into it so it can be compared apples-to-apples
# with a fully jinja-rendered project. This is necessary because the experimental
# parser will likely add features that the existing static parser will fail on
# so comparing those directly would give us bad results. The comparison will be
# conducted after this model has been fully rendered either by the static parser
# or by full jinja rendering
if isinstance(experimental_sample, dict):
model_parser_copy = self.partial_deepcopy()
exp_sample_node = deepcopy(node)
exp_sample_config = deepcopy(config)
model_parser_copy.populate(exp_sample_node, exp_sample_config, experimental_sample)
# use the experimental parser exclusively if the flag is on
if flags.USE_EXPERIMENTAL_PARSER:
statically_parsed = self.run_experimental_parser(node)
# run the stable static parser unless it is explicitly turned off
else:
statically_parsed = self.run_static_parser(node)
# if the static parser succeeded, extract some data in easy-to-compare formats
if isinstance(statically_parsed, dict):
# only sample jinja for the purpose of comparing with the stable static parser
# if we know we don't need to fall back to jinja (i.e. - nothing to compare
# with jinja v jinja).
# This means we skip sampling for 40% of the 1/5000 samples. We could run the
# sampling rng here, but the effect would be the same since we would only roll
# it 40% of the time. So I've opted to keep all the rng code colocated above.
if stable_sample and not flags.USE_EXPERIMENTAL_PARSER:
# if this will _never_ mutate anything `self` we could avoid these deep copies,
# but we can't really guarantee that going forward.
model_parser_copy = self.partial_deepcopy()
jinja_sample_node = deepcopy(node)
jinja_sample_config = deepcopy(config)
# rendering mutates the node and the config
super(ModelParser, model_parser_copy).render_update(
jinja_sample_node, jinja_sample_config
)
# update the unrendered config with values from the static parser.
# values from yaml files are in there already
self.populate(node, config, statically_parsed)
# if we took a jinja sample, compare now that the base node has been populated
if jinja_sample_node is not None and jinja_sample_config is not None:
result = _get_stable_sample_result(
jinja_sample_node, jinja_sample_config, node, config
)
# if we took an experimental sample, compare now that the base node has been populated
if exp_sample_node is not None and exp_sample_config is not None:
result = _get_exp_sample_result(
exp_sample_node,
exp_sample_config,
node,
config,
)
self.manifest._parsing_info.static_analysis_parsed_path_count += 1
# if the static parser didn't succeed, fall back to jinja
else:
# jinja rendering
super().render_update(node, config)
# if sampling, add the correct messages for tracking
if exp_sample and isinstance(experimental_sample, str):
if experimental_sample == "cannot_parse":
result += ["01_experimental_parser_cannot_parse"]
elif experimental_sample == "has_banned_macro":
result += ["08_has_banned_macro"]
elif stable_sample and isinstance(statically_parsed, str):
if statically_parsed == "cannot_parse":
result += ["81_stable_parser_cannot_parse"]
elif statically_parsed == "has_banned_macro":
result += ["88_has_banned_macro"]
# only send the tracking event if there is at least one result code
if result:
# fire a tracking event. this fires one event for every sample
# so that we have data on a per file basis. Not only can we expect
# no false positives or misses, we can expect the number model
# files parseable by the experimental parser to match our internal
# testing.
if tracking.active_user is not None: # None in some tests
tracking.track_experimental_parser_sample(
{
"project_id": self.root_project.hashed_name(),
"file_id": utils.get_hash(node),
"status": result,
}
)
def run_static_parser(self, node: ModelNode) -> Optional[Union[str, Dict[str, List[Any]]]]:
# if any banned macros have been overridden by the user, we cannot use the static parser.
if self._has_banned_macro(node):
return "has_banned_macro"
# run the stable static parser and return the results
try:
statically_parsed = py_extract_from_source(node.raw_code)
return _shift_sources(statically_parsed)
# if we want information on what features are barring the static
# parser from reading model files, this is where we would add that
# since that information is stored in the `ExtractionError`.
except ExtractionError:
return "cannot_parse"
def run_experimental_parser(
self, node: ModelNode
) -> Optional[Union[str, Dict[str, List[Any]]]]:
# if any banned macros have been overridden by the user, we cannot use the static parser.
if self._has_banned_macro(node):
return "has_banned_macro"
# run the experimental parser and return the results
try:
# for now, this line calls the stable static parser since there are no
# experimental features. Change `py_extract_from_source` to the new
# experimental call when we add additional features.
experimentally_parsed = py_extract_from_source(node.raw_code)
return _shift_sources(experimentally_parsed)
# if we want information on what features are barring the experimental
# parser from reading model files, this is where we would add that
# since that information is stored in the `ExtractionError`.
except ExtractionError:
return "cannot_parse"
# checks for banned macros
def _has_banned_macro(self, node: ModelNode) -> bool:
# first check if there is a banned macro defined in scope for this model file
root_project_name = self.root_project.project_name
project_name = node.package_name
banned_macros = ["ref", "source", "config"]
all_banned_macro_keys: Iterator[str] = chain.from_iterable(
map(
lambda name: [f"macro.{project_name}.{name}", f"macro.{root_project_name}.{name}"],
banned_macros,
)
)
return reduce(
lambda z, key: z or (key in self.manifest.macros), all_banned_macro_keys, False
)
# this method updates the model node rendered and unrendered config as well
# as the node object. Used to populate these values when circumventing jinja
# rendering like the static parser.
def populate(self, node: ModelNode, config: ContextConfig, statically_parsed: Dict[str, Any]):
# manually fit configs in
config._config_call_dict = _get_config_call_dict(statically_parsed)
# if there are hooks present this, it WILL render jinja. Will need to change
# when the experimental parser supports hooks
self.update_parsed_node_config(node, config)
# update the unrendered config with values from the file.
# values from yaml files are in there already
node.unrendered_config.update(dict(statically_parsed["configs"]))
# set refs and sources on the node object
refs: List[RefArgs] = []
for ref in statically_parsed["refs"]:
name = ref.get("name")
package = ref.get("package")
version = ref.get("version")
refs.append(RefArgs(name, package, version))
node.refs += refs
node.sources += statically_parsed["sources"]
# configs don't need to be merged into the node because they
# are read from config._config_call_dict
# the manifest is often huge so this method avoids deepcopying it
def partial_deepcopy(self):
return ModelParser(deepcopy(self.project), self.manifest, deepcopy(self.root_project))
# pure function. safe to use elsewhere, but unlikely to be useful outside this file.
def _get_config_call_dict(static_parser_result: Dict[str, Any]) -> Dict[str, Any]:
config_call_dict: Dict[str, Any] = {}
for c in static_parser_result["configs"]:
ContextConfig._add_config_call(config_call_dict, {c[0]: c[1]})
return config_call_dict
# TODO if we format sources in the extractor to match this type, we won't need this function.
def _shift_sources(static_parser_result: Dict[str, List[Any]]) -> Dict[str, List[Any]]:
shifted_result = deepcopy(static_parser_result)
source_calls = []
for s in static_parser_result["sources"]:
source_calls.append([s[0], s[1]])
shifted_result["sources"] = source_calls
return shifted_result
# returns a list of string codes to be sent as a tracking event
def _get_exp_sample_result(
sample_node: ModelNode,
sample_config: ContextConfig,
node: ModelNode,
config: ContextConfig,
) -> List[str]:
result: List[Tuple[int, str]] = _get_sample_result(sample_node, sample_config, node, config)
def process(codemsg):
code, msg = codemsg
return f"0{code}_experimental_{msg}"
return list(map(process, result))
# returns a list of string codes to be sent as a tracking event
def _get_stable_sample_result(
sample_node: ModelNode,
sample_config: ContextConfig,
node: ModelNode,
config: ContextConfig,
) -> List[str]:
result: List[Tuple[int, str]] = _get_sample_result(sample_node, sample_config, node, config)
def process(codemsg):
code, msg = codemsg
return f"8{code}_stable_{msg}"
return list(map(process, result))
# returns a list of string codes that need a single digit prefix to be prepended
# before being sent as a tracking event
def _get_sample_result(
sample_node: ModelNode,
sample_config: ContextConfig,
node: ModelNode,
config: ContextConfig,
) -> List[Tuple[int, str]]:
result: List[Tuple[int, str]] = []
# look for false positive configs
for k in sample_config._config_call_dict.keys():
if k not in config._config_call_dict.keys():
result += [(2, "false_positive_config_value")]
break
# look for missed configs
for k in config._config_call_dict.keys():
if k not in sample_config._config_call_dict.keys():
result += [(3, "missed_config_value")]
break
# look for false positive sources
for s in sample_node.sources:
if s not in node.sources:
result += [(4, "false_positive_source_value")]
break
# look for missed sources
for s in node.sources:
if s not in sample_node.sources:
result += [(5, "missed_source_value")]
break
# look for false positive refs
for r in sample_node.refs:
if r not in node.refs:
result += [(6, "false_positive_ref_value")]
break
# look for missed refs
for r in node.refs:
if r not in sample_node.refs:
result += [(7, "missed_ref_value")]
break
# if there are no errors, return a success value
if not result:
result = [(0, "exact_match")]
return result