开始使用 Dapr 客户端 Python SDK

如何使用 Dapr Python SDK 启动和运行

Dapr 客户端包允许您从 Python 应用程序中与其他 Dapr 应用程序进行交互。

前提

导入客户端包

Dapr 包包含 DaprClient ,该工具包将用于创建和使用客户端。

from dapr.clients import DaprClient

构建块

Python SDK 允许你与所有的 Dapr 构建块交互。

调用服务

from dapr.clients import DaprClient

with DaprClient() as d:
    # invoke a method (gRPC or HTTP GET)    
    resp = d.invoke_method('service-to-invoke', 'method-to-invoke', data='{"message":"Hello World"}')

    # for other HTTP verbs the verb must be specified
    # invoke a 'POST' method (HTTP only)    
    resp = d.invoke_method('service-to-invoke', 'method-to-invoke', data='{"id":"100", "FirstName":"Value", "LastName":"Value"}', http_verb='post')

保存和获取应用程序状态

from dapr.clients import DaprClient

with DaprClient() as d:
    # Save state
    d.save_state(store_name="statestore", key="key1", value="value1")

    # Get state
    data = d.get_state(store_name="statestore", key="key1").data

    # Delete state
    d.delete_state(store_name="statestore", key="key1")

查询应用程序状态(Alpha)

    from dapr import DaprClient

    query = '''
    {
        "filter": {
            "EQ": { "value.state": "CA" }
        },
        "sort": [
            {
                "key": "value.person.id",
                "order": "DESC"
            }
        ]
    }
    '''

    with DaprClient() as d:
        resp = d.query_state(
            store_name='state_store',
            query=query,
            states_metadata={"metakey": "metavalue"},  # optional
        )

发布和订阅消息

发布消息
from dapr.clients import DaprClient

with DaprClient() as d:
    resp = d.publish_event(pubsub_name='pubsub', topic='TOPIC_A', data='{"message":"Hello World"}')
订阅消息
from cloudevents.sdk.event import v1
from dapr.ext.grpc import App
import json

app = App()

# Default subscription for a topic
@app.subscribe(pubsub_name='pubsub', topic='TOPIC_A')
def mytopic(event: v1.Event) -> None:
    data = json.loads(event.Data())
    print(f'Received: id={data["id"]}, message="{data ["message"]}"' 
          ' content_type="{event.content_type}"',flush=True)

# Specific handler using Pub/Sub routing
@app.subscribe(pubsub_name='pubsub', topic='TOPIC_A',
               rule=Rule("event.type == \"important\"", 1))
def mytopic_important(event: v1.Event) -> None:
    data = json.loads(event.Data())
    print(f'Received: id={data["id"]}, message="{data ["message"]}"' 
          ' content_type="{event.content_type}"',flush=True)

与输出绑定交互

from dapr.clients import DaprClient

with DaprClient() as d:
    resp = d.invoke_binding(name='kafkaBinding', operation='create', data='{"message":"Hello World"}')

检索密钥

from dapr.clients import DaprClient

with DaprClient() as d:
    resp = d.get_secret(store_name='localsecretstore', key='secretKey')

获取配置

from dapr.clients import DaprClient

with DaprClient() as d:
    # Get Configuration
    configuration = d.get_configuration(store_name='configurationstore', keys=['orderId'], config_metadata={})

相关链接