EventBus Service¶

This core service handles subscriptions and publications. It may be replaced by a facade to an existing event bus/mq manager.

It exposes user-facing endpoints that are used by other services to subscribe to events and publish events.

There are two service-specific configuration file options.

Environment variables¶

Logging¶

You can set the EVENTBUS_DEBUG_LEVEL (all upper-cased) or DEBUG_LEVEL environment variables to DEBUG to add additional information in the console for the launched service. It defaults to INFO. (Please note that setting DEBUG_LEVEL to DEBUG will produce tons of logs.)

The possible values are NOTSET, DEBUG, INFO, WARNING, ERROR, and FATAL. Those values are from the most verbose, NOTSET, which shows all logs, to the least verbose, FATAL, which only shows fatal errors.

If EVENTBUS_DEBUG_LEVEL is not defined then the value of DEBUG_LEVEL is used (or INFO if DEBUG_LEVEL is not defined either).

Access logs are only shown at NOTSET and DEBUG levels.

Configuration options¶

You can also set the two configuration options using environment variables:

EVENTBUS_POST_TIMEOUT_SECONDS sets the post_timeout_seconds value.
EVENTBUS_WAITRESS_THREADS_COUNT sets the waitress_threads_count value.

If those environment variables are defined, they override the values in the configuration file.

Configuration file¶

This service has a configuration file (eventbus.yaml by default) that describes the host, port, ssl_context, and trusted_authorities to use. It can also enable insecure logins.

If no configuration file is found it will default to the following values:

apiVersion: opentestfactory.org/v1alpha1
kind: EventBusConfig
current-context: default
contexts:
- context:
    port: 38368
    host: 127.0.0.1
    ssl_context: adhoc
    enable_insecure_login: false
    post_timeout_seconds: 10
    waitress_threads_count: 10
  name: default

The configuration included in the ‘allinone’ image is described in “Common settings.” The listening port is 38368 and the bind address is 0.0.0.0 as the service exposes user-facing endpoints.

Two service-specific configuration options can be refined.

EventBus limits¶

All those limits must be integers. If the entry is missing, the default value will be assumed. They must be defined in the currently-used context.

`post_timeout_seconds`¶

post_timeout_seconds limits the time the event bus waits for a subscriber to respond to a publication. It must be at least 1. If not specified, defaults to 10.

If the subscriber does not respond within the specified time, the publication dispatch is considered a failure and will be replayed if the maximum publication attempt has not been reached.

`waitress_threads_count`¶

waitress_threads_count sets the number of threads handling incoming requests. It must be at least 4. If not specified, defaults to 10.

Launch command¶

If you want to manually start the event bus service, use the following command:

python -m opentf.core.eventbus [--context context] [--config configfile]

Additional command-line options are available and described in “Command-line options.”