Source code for airflow.providers.grpc.hooks.grpc

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"""GRPC Hook"""
from typing import Any, Callable, Dict, Generator, List, Optional

import grpc
from google import auth as google_auth
from google.auth import jwt as google_auth_jwt
from google.auth.transport import (
    grpc as google_auth_transport_grpc,
    requests as google_auth_transport_requests,
)

from airflow.exceptions import AirflowConfigException
from airflow.hooks.base import BaseHook


[docs]class GrpcHook(BaseHook): """ General interaction with gRPC servers. :param grpc_conn_id: The connection ID to use when fetching connection info. :param interceptors: a list of gRPC interceptor objects which would be applied to the connected gRPC channel. None by default. Each interceptor should based on or extends the four official gRPC interceptors, eg, UnaryUnaryClientInterceptor, UnaryStreamClientInterceptor, StreamUnaryClientInterceptor, StreamStreamClientInterceptor. :param custom_connection_func: The customized connection function to return gRPC channel. A callable that accepts the connection as its only arg. """
[docs] conn_name_attr = 'grpc_conn_id'
[docs] default_conn_name = 'grpc_default'
[docs] conn_type = 'grpc'
[docs] hook_name = 'GRPC Connection'
@staticmethod
[docs] def get_connection_form_widgets() -> Dict[str, Any]: """Returns connection widgets to add to connection form""" from flask_appbuilder.fieldwidgets import BS3TextFieldWidget from flask_babel import lazy_gettext from wtforms import StringField return { "extra__grpc__auth_type": StringField( lazy_gettext('Grpc Auth Type'), widget=BS3TextFieldWidget() ), "extra__grpc__credential_pem_file": StringField( lazy_gettext('Credential Keyfile Path'), widget=BS3TextFieldWidget() ), "extra__grpc__scopes": StringField( lazy_gettext('Scopes (comma separated)'), widget=BS3TextFieldWidget()
), } def __init__( self, grpc_conn_id: str = default_conn_name, interceptors: Optional[List[Callable]] = None, custom_connection_func: Optional[Callable] = None, ) -> None: super().__init__() self.grpc_conn_id = grpc_conn_id self.conn = self.get_connection(self.grpc_conn_id) self.extras = self.conn.extra_dejson self.interceptors = interceptors if interceptors else [] self.custom_connection_func = custom_connection_func
[docs] def get_conn(self) -> grpc.Channel: base_url = self.conn.host if self.conn.port: base_url = base_url + ":" + str(self.conn.port) auth_type = self._get_field("auth_type") if auth_type == "NO_AUTH": channel = grpc.insecure_channel(base_url) elif auth_type in {"SSL", "TLS"}: credential_file_name = self._get_field("credential_pem_file") with open(credential_file_name, "rb") as credential_file: creds = grpc.ssl_channel_credentials(credential_file.read()) channel = grpc.secure_channel(base_url, creds) elif auth_type == "JWT_GOOGLE": credentials, _ = google_auth.default() jwt_creds = google_auth_jwt.OnDemandCredentials.from_signing_credentials(credentials) channel = google_auth_transport_grpc.secure_authorized_channel(jwt_creds, None, base_url) elif auth_type == "OATH_GOOGLE": scopes = self._get_field("scopes").split(",") credentials, _ = google_auth.default(scopes=scopes) request = google_auth_transport_requests.Request() channel = google_auth_transport_grpc.secure_authorized_channel(credentials, request, base_url) elif auth_type == "CUSTOM": if not self.custom_connection_func: raise AirflowConfigException( "Customized connection function not set, not able to establish a channel" ) channel = self.custom_connection_func(self.conn) else: raise AirflowConfigException( "auth_type not supported or not provided, channel cannot be established, " f"given value: {str(auth_type)}" ) if self.interceptors: for interceptor in self.interceptors: channel = grpc.intercept_channel(channel, interceptor) return channel
[docs] def run( self, stub_class: Callable, call_func: str, streaming: bool = False, data: Optional[dict] = None ) -> Generator: """Call gRPC function and yield response to caller""" if data is None: data = {} with self.get_conn() as channel: stub = stub_class(channel) try: rpc_func = getattr(stub, call_func) response = rpc_func(**data) if not streaming: yield response else: yield from response except grpc.RpcError as ex: self.log.exception( "Error occurred when calling the grpc service: %s, method: %s \ status code: %s, error details: %s", stub.__class__.__name__, call_func, ex.code(), ex.details(), ) raise ex
def _get_field(self, field_name: str) -> str: """ Fetches a field from extras, and returns it. This is some Airflow magic. The grpc hook type adds custom UI elements to the hook page, which allow admins to specify scopes, credential pem files, etc. They get formatted as shown below. """ full_field_name = f'extra__grpc__{field_name}' return self.extras[full_field_name]

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