Cobalt package

Cobalt

class cobalt.Cobalt(config)

Bases: utils.service.Service

Main service class responsible for setting up and managing all Cobalt components.

VERSION = '0.1'

Version of the current Cobalt app, used to ensure consistency inside the cluster.

_attach_handlers()

Utility method to ensure graceful stops when receiving termination signals.

static _create_etcd(context)

Factory method for creating the etcd.Client to be used inside the app.

Parameters:context (dict) – The config for the client Returns:Client to be used by the APP Return type:etcd.Client

static _create_machine_manager(etcd_client)

Factory method for creating the MachineManager to be used inside the app.

Parameters:etcd_client (etcd.Client) – The client responsible for communicating with the database Returns:The machine manager to be used by the APP Return type:MachineManager

static _create_volume_manager(etcd_client)

Factory method for creating the VolumeManger to be used inside the app.

Parameters:etcd_client (etcd.Client) – The client responsible for communicating with the database Returns:The volume manager to be used by the APP Return type:VolumeManager

_ensure_versions_match()

Makes sure the versions match (the defined one and one remote).

If this is the first node it will write its version upstream

Returns:If the versions match or not Return type:bool

_handler(*_)

The handler that will execute when a signal is caught. Purpose: stopping the node.

_write_version()

Utility method to write current version upstream.

Returns:If the write operation was successful or not Return type:bool

filter_services()

It will only take the services present in the config given to Cobalt.

setup_services()

A method to prepare the possible services that Cobalt can have.

start()

Starts Cobalt only if the ETCD versions match with the defined one.

Returns:If the start operation succeded or not Return type:bool

stop()

A means to gracefully stop all services registered to Cobalt.

Returns:Returns true in any occasion Return type:bool