The current webserver UI uses the Flask-Admin extension. The new webserver UI uses the [Flask-AppBuilder (FAB)](https://github.com/dpgaspar/Flask-AppBuilder) extension. FAB has built-in authentication support and Role-Based Access Control (RBAC), which provides configurable roles and permissions for individual users.
To turn on this feature, in your airflow.cfg file (under [webserver]), set the configuration variable `rbac = True`, and then run `airflow` command, which will generate the `webserver_config.py` file in your $AIRFLOW_HOME.
FAB has built-in authentication support for DB, OAuth, OpenID, LDAP, and REMOTE_USER. The default auth type is `AUTH_DB`.
For any other authentication type (OAuth, OpenID, LDAP, REMOTE_USER), see the [Authentication section of FAB docs](http://flask-appbuilder.readthedocs.io/en/latest/security.html#authentication-methods) for how to configure variables in webserver_config.py file.
Once you modify your config file, run `airflow initdb` to generate new tables for RBAC support (these tables will have the prefix `ab_`).
There are five roles created for Airflow by default: Admin, User, Op, Viewer, and Public. To configure roles/permissions, go to the `Security` tab and click `List Roles` in the new UI.
- Airflow dag home page is now `/home` (instead of `/admin`).
- All ModelViews in Flask-AppBuilder follow a different pattern from Flask-Admin. The `/admin` part of the url path will no longer exist. For example: `/admin/connection` becomes `/connection/list`, `/admin/connection/new` becomes `/connection/add`, `/admin/connection/edit` becomes `/connection/edit`, etc.
- Due to security concerns, the new webserver will no longer support the features in the `Data Profiling` menu of old UI, including `Ad Hoc Query`, `Charts`, and `Known Events`.
With Airflow 1.9 or lower, there were two connection strings for the Google Cloud operators, both `google_cloud_storage_default` and `google_cloud_default`. This can be confusing and therefore the `google_cloud_storage_default` connection id has been replaced with `google_cloud_default` to make the connection id consistent across Airflow.
SSH Hook now uses the Paramiko library to create an ssh client connection, instead of the sub-process based ssh command execution previously (<1.9.0),sothisisbackwardincompatible.
The airflow.hooks.S3_hook.S3Hook has been switched to use boto3 instead of the older boto (a.k.a. boto2). This results in a few backwards incompatible changes to the following classes: S3Hook:
- the return type of objects returned by `get_bucket` is now boto3.s3.Bucket
- the return type of `get_key`, and `get_wildcard_key` is now an boto3.S3.Object.
If you are using any of these in your DAGs and specify a connection ID you will need to update the parameter name for the connection to "aws_conn_id": S3ToHiveTransfer, S3PrefixSensor, S3KeySensor, RedshiftToS3Transfer.
A logger is the entry point into the logging system. Each logger is a named bucket to which messages can be written for processing. A logger is configured to have a log level. This log level describes the severity of the messages that the logger will handle. Python defines the following log levels: DEBUG, INFO, WARNING, ERROR or CRITICAL.
Each message that is written to the logger is a Log Record. Each log record contains a log level indicating the severity of that specific message. A log record can also contain useful metadata that describes the event that is being logged. This can include details such as a stack trace or an error code.
When a message is given to the logger, the log level of the message is compared to the log level of the logger. If the log level of the message meets or exceeds the log level of the logger itself, the message will undergo further processing. If it doesn’t, the message will be ignored.
Once a logger has determined that a message needs to be processed, it is passed to a Handler. This configuration is now more flexible and can be easily be maintained in a single file.
Airflow's logging mechanism has been refactored to use Python’s builtin `logging` module to perform logging of the application. By extending classes with the existing `LoggingMixin`, all the logging will go through a central logger. Also the `BaseHook` and `BaseOperator` already extend this class, so it is easily available to do logging.
The main benefit is easier configuration of the logging by setting a single centralized python file. Disclaimer; there is still some inline configuration, but this will be removed eventually. The new logging class is defined by setting the dotted classpath in your `~/airflow/airflow.cfg` file:
```
# Logging class
# Specify the class that will specify the logging configuration
The logging configuration file needs to be on the `PYTHONPATH`, for example `$AIRFLOW_HOME/config`. This directory is loaded by default. Any directory may be added to the `PYTHONPATH`, this might be handy when the config is in another directory or a volume is mounted in case of Docker.
The config can be taken from `airflow/config_templates/airflow_local_settings.py` as a starting point. Copy the contents to `${AIRFLOW_HOME}/config/airflow_local_settings.py`, and alter the config as is preferred.
To customize the logging (for example, use logging rotate), define one or more of the logging handles that [Python has to offer](https://docs.python.org/3/library/logging.handlers.html). For more details about the Python logging, please refer to the [official logging documentation](https://docs.python.org/3/library/logging.html).
The `file_task_handler` logger has been made more flexible. The default format can be changed, `{dag_id}/{task_id}/{execution_date}/{try_number}.log` by supplying Jinja templating in the `FILENAME_TEMPLATE` configuration variable. See the `file_task_handler` for more information.
If you are logging to Google cloud storage, please see the [Google cloud platform documentation](https://airflow.incubator.apache.org/integration.html#gcp-google-cloud-platform) for logging instructions.
If you are using S3, the instructions should be largely the same as the Google cloud platform instructions above. You will need a custom logging config. The `REMOTE_BASE_LOG_FOLDER` configuration key in your airflow config has been removed, therefore you will need to take the following steps:
- Copy the logging configuration from [`airflow/config_templates/airflow_logging_settings.py`](https://github.com/apache/incubator-airflow/blob/master/airflow/config_templates/airflow_local_settings.py).
- Place it in a directory inside the Python import path `PYTHONPATH`. If you are using Python 2.7, ensuring that any `__init__.py` files exist so that it is importable.
- Set the `logging_config_class` to the filename and dict. For example, if you place `custom_logging_config.py` on the base of your pythonpath, you will need to set `logging_config_class = custom_logging_config.LOGGING_CONFIG` in your config as Airflow 1.8.
- If you're using the `google_cloud_conn_id` or `dataproc_cluster` argument names explicitly in `contrib.operators.Dataproc{*}Operator`(s), be sure to rename them to `gcp_conn_id` or `cluster_name`, respectively. We've renamed these arguments for consistency. (AIRFLOW-1323)
-`contrib.hooks.gcp_dataflow_hook.DataFlowHook` starts to use `--runner=DataflowRunner` instead of `DataflowPipelineRunner`, which is removed from the package `google-cloud-dataflow-0.6.0`.
The frequency with which the scheduler should relist the contents of the DAG directory. If while developing +dags, they are not being picked up, have a look at this number and decrease it when necessary.
