Python 更新后未在web UI中加载日志

我们最近从1.10.3（Python 2.7）更新到了1.10.7。除了与web UI相关的两个问题（不是1.10.3中的问题）之外，一切似乎都正常工作：

（1） 如果放大子DAG，然后单击“代码”，则显示的名称为parent.subdag，与预期的一样，但显示的代码是针对父级的。它没有显示任何类型的错误，并且子DAG运行正常，因此不清楚从何处开始研究这个问题

（2） 更重要的是，尝试加载任何日志会导致恒定加载符号。检查页面会显示错误：

Traceback (most recent call last):
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask/app.py", line 1951, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask/app.py", line 1820, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask/app.py", line 1949, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask/app.py", line 1935, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/www_rbac/decorators.py", line 121, in wrapper
    return f(self, *args, **kwargs)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/flask_appbuilder/security/decorators.py", line 26, in wraps
    return f(self, *args, **kwargs)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/www_rbac/decorators.py", line 56, in wrapper
    return f(*args, **kwargs)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/utils/db.py", line 74, in wrapper
    return func(*args, **kwargs)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/www_rbac/views.py", line 637, in get_logs_with_metadata
    logs, metadata = _get_logs_with_metadata(try_number, metadata)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/www_rbac/views.py", line 628, in _get_logs_with_metadata
    logs, metadatas = handler.read(ti, try_number, metadata=metadata)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/utils/log/file_task_handler.py", line 169, in read
    log, metadata = self._read(task_instance, try_number_element, metadata)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/utils/log/file_task_handler.py", line 98, in _read
    log_relative_path = self._render_filename(ti, try_number)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/utils/log/file_task_handler.py", line 75, in _render_filename
    jinja_context = ti.get_template_context()
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/utils/db.py", line 74, in wrapper
    return func(*args, **kwargs)
  File "/home/username/.conda/envs/apache_airflow_env/lib/python2.7/site-packages/airflow/models/taskinstance.py", line 1149, in get_template_context
    if 'tables' in task.params:
TypeError: argument of type 'NoneType' is not iterable

日志被写入机器上的预期输出位置（我们没有使用远程日志记录），因此日志本身并不是丢失的。不确定这是气流错误还是配置问题

从我们的配置文件：

# Log format
log_format = [%%(asctime)s] {%%(filename)s:%%(lineno)d} %%(levelname)s - %%(message)s
simple_log_format = %%(asctime)s %%(levelname)s - %%(message)s

# Flag to enable/disable Colored logs in Console
# Colour the logs when the controlling terminal is a TTY.
colored_console_log = False

# Log format for when Colored logs is enabled
# colored_log_format = [%%(blue)s%%(asctime)s%%(reset)s] {{%%(blue)s%%(filename)s:%%(reset)s%%(lineno)d}} %%(log_color)s%%(levelname)s%%(reset)s - %%(log_color)s%%(message)s%%(reset)s
# colored_formatter_class = airflow.utils.log.colored_log.CustomTTYColoredFormatter

# Log filename format
log_filename_template = {{ ti.dag_id }}/{{ ti.task_id }}/{{ ts }}/{{ try_number }}.log
log_processor_filename_template = {{ filename }}.log
...
# Name of handler to read task instance logs.
# Default to use file task handler.
# task_log_reader = file.task
task_log_reader = task