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Arranger Service

This core service orchestrates workflow executions.

It exposes no user-facing endpoints.

There are five service-specific configuration file options.

Environment variables

Logging

You can set the ARRANGER_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 ARRANGER_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 five configuration options using environment variables:

  • ARRANGER_DEFAULT_TIMEOUT_MINUTES sets the default maximum duration for a workflow, in minutes.
  • ARRANGER_MAX_JOB_STEPS limits the number of steps in a workflow job.
  • ARRANGER_MAX_JOBS limits the number of jobs in a workflow.
  • ARRANGER_MAX_PARALLEL limits the number of jobs in a workflow that can be running in parallel.
  • ARRANGER_MAX_WORKERS limits the number of jobs in a workflow that can be running at any given time.

They must be integers. If those environment variables are defined, they override the values in the configuration file.

Configuration file

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

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

apiVersion: opentestfactory.org/v1beta2
kind: ServiceConfig
current-context: default
contexts:
- context:
    port: 443
    host: 127.0.0.1
    ssl_context: adhoc
    eventbus:
      endpoint: https://127.0.0.1:38368
      token: invalid
    default_timeout_minutes: 360
    max_job_steps: 10240
    max_jobs: 1024
    max_parallel: 1
    max_workers: 256
  name: default

The configuration included in the ‘allinone’ image is described in “Common settings.” The listening port is 7781 and the bind address is 127.0.0.1 as the service exposes no user-facing endpoints.

Five service-specific configuration options can be refined.

Workflow 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.

max_jobs limits the number of jobs in a workflow. If a workflow contains or generates more jobs than this limit, the workflow will be canceled. If not specified, defaults to 1024.

max_job_steps limits the number of steps in a workflow. If a job contains or generates more steps than this limit, the job will be canceled. If not specified, defaults to 10240.

max_workers limits the number of jobs in a workflow that can be running at any given time. If not specified, defaults to 256.

max_parallel limits the number of jobs in a workflow that can be running in parallel if strategy.max-parallel is not defined in a workflow. If not specified, defaults to 1.

default_timeout_minutes is the default maximum duration for a workflow, in minutes. If not specified, defaults to 360 minutes (6 hours).

Subscriptions

The arranger service subscribes to the following events:

kind apiVersion
Workflow opentestfactory.org/v1
WorkflowCancellation opentestfactory.org/v1
GeneratorResult opentestfactory.org/v1
ProviderResult opentestfactory.org/v1
ExecutionResult opentestfactory.org/v1alpha1
ExecutionError opentestfactory.org/v1alpha1

The arranger service exposes an /inbox endpoint that is used by the event bus to post relevant events.

Launch command

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

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

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