airflow/www/decorators.py

#
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# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
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#   http://www.apache.org/licenses/LICENSE-2.0
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from __future__ import annotations

import functools
import gzip
import json
import logging
from io import BytesIO as IO
from itertools import chain
from typing import Callable, TypeVar, cast

import pendulum
from flask import after_this_request, g, request
from pendulum.parsing.exceptions import ParserError

from airflow.models import Log
from airflow.utils.log import secrets_masker
from airflow.utils.session import create_session

T = TypeVar("T", bound=Callable)

logger = logging.getLogger(__name__)


def _mask_variable_fields(extra_fields):
    """
    The variable requests values and args comes in this form:
    [('key', 'key_content'),('val', 'val_content'), ('description', 'description_content')]
    So we need to mask the 'val_content' field if 'key_content' is in the mask list.
    """
    result = []
    keyname = None
    for k, v in extra_fields:
        if k == "key":
            keyname = v
            result.append((k, v))
        elif keyname and k == "val":
            x = secrets_masker.redact(v, keyname)
            result.append((k, x))
            keyname = None
        else:
            result.append((k, v))
    return result


def _mask_connection_fields(extra_fields):
    """Mask connection fields."""
    result = []
    for k, v in extra_fields:
        if k == "extra":
            try:
                extra = json.loads(v)
                extra = [(k, secrets_masker.redact(v, k)) for k, v in extra.items()]
                result.append((k, json.dumps(dict(extra))))
            except json.JSONDecodeError:
                result.append((k, "Encountered non-JSON in `extra` field"))
        else:
            result.append((k, secrets_masker.redact(v, k)))
    return result


def action_logging(func: Callable | None = None, event: str | None = None) -> Callable[[T], T]:
    """Decorator to log user actions."""

    def log_action(f: T) -> T:
        @functools.wraps(f)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True  # Hide from pytest traceback.

            with create_session() as session:
                if g.user.is_anonymous:
                    user = "anonymous"
                else:
                    user = f"{g.user.username} ({g.user.get_full_name()})"

                fields_skip_logging = {"csrf_token", "_csrf_token"}
                extra_fields = [
                    (k, secrets_masker.redact(v, k))
                    for k, v in chain(request.values.items(multi=True), request.view_args.items())
                    if k not in fields_skip_logging
                ]
                if event and event.startswith("variable."):
                    extra_fields = _mask_variable_fields(extra_fields)
                if event and event.startswith("connection."):
                    extra_fields = _mask_connection_fields(extra_fields)

                params = {k: v for k, v in chain(request.values.items(), request.view_args.items())}

                log = Log(
                    event=event or f.__name__,
                    task_instance=None,
                    owner=user,
                    extra=str(extra_fields),
                    task_id=params.get("task_id"),
                    dag_id=params.get("dag_id"),
                )

                if "execution_date" in request.values:
                    execution_date_value = request.values.get("execution_date")
                    try:
                        log.execution_date = pendulum.parse(execution_date_value, strict=False)
                    except ParserError:
                        logger.exception(
                            "Failed to parse execution_date from the request: %s", execution_date_value
                        )

                session.add(log)

            return f(*args, **kwargs)

        return cast(T, wrapper)

    if func:
        return log_action(func)
    return log_action


def gzipped(f: T) -> T:
    """Decorator to make a view compressed."""

    @functools.wraps(f)
    def view_func(*args, **kwargs):
        @after_this_request
        def zipper(response):
            accept_encoding = request.headers.get("Accept-Encoding", "")

            if "gzip" not in accept_encoding.lower():
                return response

            response.direct_passthrough = False

            if (
                response.status_code < 200
                or response.status_code >= 300
                or "Content-Encoding" in response.headers
            ):
                return response
            gzip_buffer = IO()
            gzip_file = gzip.GzipFile(mode="wb", fileobj=gzip_buffer)
            gzip_file.write(response.data)
            gzip_file.close()

            response.data = gzip_buffer.getvalue()
            response.headers["Content-Encoding"] = "gzip"
            response.headers["Vary"] = "Accept-Encoding"
            response.headers["Content-Length"] = len(response.data)

            return response

        return f(*args, **kwargs)

    return cast(T, view_func)