Local Filesystem Secrets Backend

This backend is especially useful in the following use cases:

  • Development: It ensures data synchronization between all terminal windows (same as databases), and at the same time the values are retained after database restart (same as environment variable)

  • Kubernetes: It allows you to store secrets in Kubernetes Secrets or you can synchronize values using the sidecar container and a shared volume

To use variable and connection from local file, specify LocalFilesystemBackend as the backend in [secrets] section of airflow.cfg.

Available parameters to backend_kwargs:

  • variables_file_path: File location with variables data.

  • connections_file_path: File location with connections data.

Here is a sample configuration:

[secrets]
backend = airflow.secrets.local_filesystem.LocalFilesystemBackend
backend_kwargs = {"variables_file_path": "/files/var.json", "connections_file_path": "/files/conn.json"}

JSON, YAML and .env files are supported. All parameters are optional. If the file path is not passed, the backend returns an empty collection.

Storing and Retrieving Connections

If you have set connections_file_path as /files/my_conn.json, then the backend will read the file /files/my_conn.json when it looks for connections.

The file can be defined in JSON, YAML or env format. Depending on the format, the data should be saved as a URL or as a connection object. Any extra json parameters can be provided using keys like extra_dejson and extra. The key extra_dejson can be used to provide parameters as JSON object where as the key extra can be used in case of a JSON string. The keys extra and extra_dejson are mutually exclusive.

The JSON file must contain an object where the key contains the connection ID and the value contains the definition of one connection. The connection can be defined as a URI (string) or JSON object. For a guide about defining a connection as a URI, see Generating a connection URI. For a description of the connection object parameters see Connection. The following is a sample JSON file.

{
    "CONN_A": "mysql://host_a",
    "CONN_B": {
        "conn_type": "scheme",
        "host": "host",
        "schema": "schema",
        "login": "Login",
        "password": "None",
        "port": "1234"
    }
}

The YAML file structure is similar to that of a JSON. The key-value pair of connection ID and the definitions of one or more connections. In this format, the connection can be defined as a URI (string) or JSON object.

CONN_A: 'mysql://host_a'

CONN_B:
  - 'mysql://host_a'
  - 'mysql://host_b'

CONN_C:
  conn_type: scheme
  host: host
  schema: lschema
  login: Login
  password: None
  port: 1234
  extra_dejson:
    a: b
    nestedblock_dict:
      x: y

You can also define connections using a .env file. Then the key is the connection ID, and the value should describe the connection using the URI. Connection ID should not be repeated, it will raise an exception. The following is a sample file.

mysql_conn_id=mysql://log:password@13.1.21.1:3306/mysqldbrd
google_custom_key=google-cloud-platform://?extra__google_cloud_platform__key_path=%2Fkeys%2Fkey.json

Storing and Retrieving Variables

If you have set variables_file_path as /files/my_var.json, then the backend will read the file /files/my_var.json when it looks for variables.

The file can be defined in JSON, YAML or env format.

The JSON file must contain an object where the key contains the variable key and the value contains the variable value. The following is a sample JSON file.

{
    "VAR_A": "some_value",
    "var_b": "different_value"
}

The YAML file structure is similar to that of JSON, with key containing the variable key and the value containing the variable value. The following is a sample YAML file.

VAR_A: some_value
VAR_B: different_value

You can also define variable using a .env file. Then the key is the variable key, and variable should describe the variable value. The following is a sample file.

VAR_A=some_value
var_B=different_value

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