notice

This is documentation for Rasa Open Source Documentation v2.0.x, which is no longer actively maintained.
For up-to-date documentation, see the latest version (2.1.x).

Version: 2.0.x

rasa.core.brokers.pika

initialise_pika_connection

initialise_pika_connection(host: Text, username: Text, password: Text, port: Union[Text, int] = 5672, connection_attempts: int = 20, retry_delay_in_seconds: float = 5) -> "BlockingConnection"

Create a Pika BlockingConnection.

Arguments:

  • host - Pika host
  • username - username for authentication with Pika host
  • password - password for authentication with Pika host
  • port - port of the Pika host
  • connection_attempts - number of channel attempts before giving up
  • retry_delay_in_seconds - delay in seconds between channel attempts

Returns:

pika.BlockingConnection with provided parameters

initialise_pika_select_connection

initialise_pika_select_connection(parameters: "Parameters", on_open_callback: Callable[["SelectConnection"], None], on_open_error_callback: Callable[["SelectConnection", Text], None]) -> "SelectConnection"

Create a non-blocking Pika SelectConnection.

Arguments:

  • parameters - Parameters which should be used to connect.
  • on_open_callback - Callback which is called when the connection was established.
  • on_open_error_callback - Callback which is called when connecting to the broker failed.

Returns:

A callback-based connection to the RabbitMQ event broker.

initialise_pika_channel

initialise_pika_channel(host: Text, queue: Text, username: Text, password: Text, port: Union[Text, int] = 5672, connection_attempts: int = 20, retry_delay_in_seconds: float = 5) -> "BlockingChannel"

Initialise a Pika channel with a durable queue.

Arguments:

  • host - Pika host.
  • queue - Pika queue to declare.
  • username - Username for authentication with Pika host.
  • password - Password for authentication with Pika host.
  • port - port of the Pika host.
  • connection_attempts - Number of channel attempts before giving up.
  • retry_delay_in_seconds - Delay in seconds between channel attempts.

Returns:

Pika BlockingChannel with declared queue.

close_pika_channel

close_pika_channel(channel: "Channel", attempts: int = 1000, time_between_attempts_in_seconds: float = 0.001) -> None

Attempt to close Pika channel and wait until it is closed.

Arguments:

  • channel - Pika Channel to close.
  • attempts - How many times to try to confirm that the channel has indeed been closed.
  • time_between_attempts_in_seconds - Wait time between attempts to confirm closed state.

close_pika_connection

close_pika_connection(connection: "Connection") -> None

Attempt to close Pika connection.

PikaEventBroker Objects

class PikaEventBroker(EventBroker)

Pika-based event broker for publishing messages to RabbitMQ.

__init__

| __init__(host: Text, username: Text, password: Text, port: Union[int, Text] = 5672, queues: Union[List[Text], Tuple[Text], Text, None] = None, should_keep_unpublished_messages: bool = True, raise_on_failure: bool = False, log_level: Union[Text, int] = os.environ.get(
| ENV_LOG_LEVEL_LIBRARIES, DEFAULT_LOG_LEVEL_LIBRARIES
| ), **kwargs: Any, ,)

Initialise RabbitMQ event broker.

Arguments:

  • host - Pika host.
  • username - Username for authentication with Pika host.
  • password - Password for authentication with Pika host.
  • port - port of the Pika host.
  • queues - Pika queues to declare and publish to.
  • should_keep_unpublished_messages - Whether or not the event broker should maintain a queue of unpublished messages to be published later in case of errors.
  • raise_on_failure - Whether to raise an exception if publishing fails. If False, keep retrying.
  • log_level - Logging level.

close

| close() -> None

Close the pika channel and connection.

rasa_environment

| @property
| rasa_environment() -> Optional[Text]

Get value of the RASA_ENVIRONMENT environment variable.

from_endpoint_config

| @classmethod
| from_endpoint_config(cls, broker_config: Optional["EndpointConfig"]) -> Optional["PikaEventBroker"]

Initialise PikaEventBroker from EndpointConfig.

Arguments:

  • broker_config - EndpointConfig to read.

Returns:

PikaEventBroker if broker_config was supplied, else None.

is_ready

| is_ready(attempts: int = 1000, wait_time_between_attempts_in_seconds: float = 0.01) -> bool

Spin until the pika channel is open.

It typically takes 50 ms or so for the pika channel to open. We'll wait up to 10 seconds just in case.

Arguments:

  • attempts - Number of retries.
  • wait_time_between_attempts_in_seconds - Wait time between retries.

Returns:

True if the channel is available, False otherwise.

publish

| publish(event: Dict[Text, Any], retries: int = 60, retry_delay_in_seconds: int = 5, headers: Optional[Dict[Text, Text]] = None) -> None

Publish event into Pika queue.

Arguments:

  • event - Serialised event to be published.
  • retries - Number of retries if publishing fails
  • retry_delay_in_seconds - Delay in seconds between retries.
  • headers - Message headers to append to the published message (key-value dictionary). The headers can be retrieved in the consumer from the headers attribute of the message's BasicProperties.

create_rabbitmq_ssl_options

create_rabbitmq_ssl_options(rabbitmq_host: Optional[Text] = None) -> Optional["pika.SSLOptions"]

Create RabbitMQ SSL options.

Requires the following environment variables to be set:

RABBITMQ_SSL_CLIENT_CERTIFICATE - path to the SSL client certificate (required) RABBITMQ_SSL_CLIENT_KEY - path to the SSL client key (required) RABBITMQ_SSL_CA_FILE - path to the SSL CA file for verification (optional) RABBITMQ_SSL_KEY_PASSWORD - SSL private key password (optional)

Details on how to enable RabbitMQ TLS support can be found here: https://www.rabbitmq.com/ssl.html#enabling-tls

Arguments:

  • rabbitmq_host - RabbitMQ hostname

Returns:

Pika SSL context of type pika.SSLOptions if the RABBITMQ_SSL_CLIENT_CERTIFICATE and RABBITMQ_SSL_CLIENT_KEY environment variables are valid paths, else None.