esdb-py

EventStoreDB Python gRPC client

NOTE: This project is still work in progress

Implemented parts

• secure connection
• basic auth
• other connection options
  • multi-node gossip
  • keepalive
• async client
• streams
  • append
  • batch append
  • delete
  • read
  • tombstone
  • filtering
  • exception handling
• subscriptions
• users

Setting things up

1. Install poetry
2. Create virtualenv (i.e. using pyenv):

pyenv install 3.10.5
pyenv virtualenv 3.10.5 esdb-py
pyenv local esdb-py

3. Install deps with poetry install
4. Start eventstore in docker: make run-esdb
5. Run the tests: pytest tests

Usage:

import datetime
import uuid

from esdb.client.client import ESClient

# For insecure connection without basic auth:
# client = ESClient("localhost:2113", tls=False)
with open("certs/ca/ca.crt", "rb") as fh:
  root_cert = fh.read()

client = ESClient("localhost:2111", root_certificates=root_cert, username="admin", password="changeit")

stream = f"test-{str(uuid.uuid4())}"

with client.connect() as conn:
    for i in range(10):
        append_result = conn.streams.append(
            stream=stream,
            event_type="test_event",
            data={"i": i, "ts": datetime.datetime.utcnow().isoformat()},
        )

    print("Forwards!")
    for result in conn.streams.read(stream=stream, count=10):
        print(result.data)

    print("Backwards!")
    for result in conn.streams.read(stream=stream, count=10, backwards=True):
        print(result.data)

    print("Forwards start from middle!")
    for result in conn.streams.read(stream=stream, count=10, revision=5):
        print(result.data)

    print("Backwards start from middle!")
    for result in conn.streams.read(stream=stream, count=10, backwards=True, revision=5):
        print(result.data)

Async example:

import asyncio

from esdb.client.client import AsyncESClient


async def append():
    client = AsyncESClient("localhost:2113", tls=False)
    async with client.connect() as conn:
        result = await conn.streams.append("stream", "type", {"x": 1})
        assert result.commit_position > 0
        async for event in conn.streams.read("stream", count=10):
            print(event)


asyncio.run(append())

Subscriptions:

from esdb.client.client import ESClient
from esdb.client.subscriptions.base import SubscriptionSettings, NackAction

client = ESClient("localhost:2113", tls=False)
stream = "stream-name"
group = "group-name"

with client.connect() as conn:
    # emit some events to the same stream
    for _ in range(10):
        conn.streams.append(stream, "foobar", b"data")

    # create a subscription
    conn.subscriptions.create_stream_subscription(
        stream=stream,
        group_name=group,
        settings=SubscriptionSettings(
            read_batch_size=5,
            live_buffer_size=10,
            history_buffer_size=10,
            checkpoint=SubscriptionSettings.DurationType(
                type=SubscriptionSettings.DurationType.Type.MS,
                value=10000,
            ),
        ),
    )

    # Read from subscription
    # This will block and wait for messages
    subscription = conn.subscriptions.subscribe_to_stream(stream, group, buffer_size=10)
    for event in subscription:
        try:
            # ... do work with the event ...
            # ack the event
            subscription.ack([event])
        except Exception as err:
            subscription.nack([event], NackAction.RETRY, reason=str(err))
          
        

Async subscriptions

from esdb.client.client import AsyncESClient
from esdb.client.subscriptions.base import SubscriptionSettings

client = AsyncESClient("localhost:2113", tls=False)

stream = "stream-foo"
group = "group-bar"

async with client.connect() as conn:
    # emit some events to the same stream
    for i in range(50):
        await conn.streams.append(stream, "foobar", {"i": i})

    # create a subscription
    await conn.subscriptions.create_stream_subscription(
        stream=stream,
        group_name=group,
        settings=SubscriptionSettings(
            max_subscriber_count=50,
            read_batch_size=5,
            live_buffer_size=10,
            history_buffer_size=10,
            consumer_strategy=SubscriptionSettings.ConsumerStrategy.ROUND_ROBIN,
            checkpoint=SubscriptionSettings.DurationType(
                type=SubscriptionSettings.DurationType.Type.MS,
                value=10000,
            ),
        ),
    )

async with client.connect() as conn:
    subscription = conn.subscriptions.subscribe_to_stream(stream=stream, group_name=group, buffer_size=5)
    async for event in subscription:
        await subscription.ack([event])