saturnin.component.controller¶

Saturnin service controllers.

Constants and variables¶

saturnin.component.controller.SVC_CTRL: Final[str] = 'iccp'¶: Service control channel name

Functions¶

saturnin.component.controller.service_thread(service: ServiceInfo, config: Config, ctrl_addr: ZMQAddress, peer_uid: UUID = None)[source]¶

Thread target code to run the service.

Parameters:

svc_descriptor – Service descriptor.
config (Config) – Service configuration.
ctrl_addr (ZMQAddress) – Address for control ZMQ socket.
peer_uid (UUID) – Peer ID.
service (ServiceInfo) –

Classes¶

class saturnin.component.controller.ServiceExecConfig(name: str)[source]¶

Bases: Config

Service executor configuration.

Parameters:: name (str) – Default conf. section name

agent: UUIDOption¶: Agent (service) identification

class saturnin.component.controller.ServiceController(*args, **kwargs)[source]¶

Bases: TracedMixin

Base service controller.

__init__(service: ServiceInfo, *, name: str = None, peer_uid: UUID = None, manager: ChannelManager = None)[source]¶

Parameters:

service (ServiceInfo) – Service to start.
name (str) – Container name.
peer_uid (UUID) – Peer ID, None means that newly generated UUID type 1 should be used.
manager (ChannelManager) – ChannelManager to be used.

configure(config: ConfigParser, section: str = None) → None[source]¶

Loads and validates service configuration, and ensures that Saturnin facilities required by service are available and properly configured.

Parameters:

config (ConfigParser) – ConfigParser instance with service configuration.
section (str) – Name of section with service configuration. If not present, uses ServiceContainer.name value.

Return type:

None

property logging_id: str¶: Returns qualified class name and agent name.

class saturnin.component.controller.DirectController(*args, **kwargs)[source]¶

Bases: ServiceController

Service controller that starts the service in current thread.

Although ICCP is used to start/stop the service, it’s not possible to perform any ICCP interactions with the service while it’s running.

Important

The service could be stopped only via automatically installed SIGINT handler.

handle_stop_controller(exc: Exception) → None[source]¶

Called when controller should stop its operation due to error condition.

Parameters:: exc (Exception) – Exception that describes the reason why component should stop.
Return type:: None

start(*, timeout: int = 10000) → None[source]¶

Start the service.

Parameters:: timeout (int) – Only for compatibility with ThreadController. The value is ignored.
Return type:: None

Important

Will not return until service is stopped via SIGINT, or exception is raised.

Raises:: ServiceError – On error in communication with service.
Parameters:: timeout (int) –
Return type:: None

stop_signal_handler(signum: int, param) → None[source]¶

The signal.signal SIGINT handler that sends ICCP STOP message to the service.

Parameters:: signum (int) –
Return type:: None

class saturnin.component.controller.ThreadController(*args, **kwargs)[source]¶

Bases: ServiceController

Service controller that starts the service in separate thread.

__init__(service: ServiceDescriptor, *, name: str = None, peer_uid: UUID = None, manager: ChannelManager = None)[source]¶

Parameters:

service (ServiceDescriptor) – Service to start.
name (str) – Container name.
peer_uid (UUID) – Peer ID, None means that newly generated UUID type 1 should be used.
manager (ChannelManager) –

handle_stop_controller(exc: Exception) → None[source]¶

Called when controller should stop its operation due to error condition.

Parameters:: exc (Exception) – Exception that describes the reason why component should stop.
Return type:: None

is_running() → bool[source]¶

Returns True if service is running.

Return type:: bool

join(timeout=None) → None[source]¶

Wait until service stops.

Parameters:: timeout – Floating point number specifying a timeout for the operation in seconds (or fractions thereof).
Return type:: None

start(*, timeout: int = 10000) → None[source]¶

Start the service.

Parameters:

timeout (int) – Timeout (in milliseconds) to wait for service to report it’s ready.

Raises:

ServiceError – On error in communication with service.
TimeoutError – When timeout expires.

Return type:

None

stop(*, timeout: int = 10000) → None[source]¶

Stop the service. Does nothing if service is not running.

Parameters:

timeout (int) – None (infinity), or timeout (in milliseconds) for the operation.

Raises:

ServiceError – On error in communication with service.
TimeoutError – When service does not stop in time.

Return type:

None

terminate() → None[source]¶

Terminate the service.

Terminate should be called ONLY when call to stop() (with sensible timeout) fails. Does nothing when service is not running.

Raises:: Error – When service termination fails.
Return type:: None