Runtime manager plugin

Runtime manager or runtime data storage stores intermediate states of VmShepherd cycles that need to be shared across multiple instances of application like:

• healthchecks status,
• try counts
• time and dates of last manage

and locking mechanism.

The locking mechanism guarantees a preset is managed by one instance at a time.

Initialization - consider following config:

runtime:
  driver: SomeHC
  param1: AAAA
  param2: BBBB
  some_x: CCC

All params will be passed as config dict to the driver init:

class vmshepherd.runtime.abstract.AbstractRuntimeData(instance_id, config=None)

Bases: object

_acquire_lock(name: str) → bool

Locks preset during manage process, any other VMgr instance won’t disrubt it.

Parameters:name (string) – Lock name in particular preset name.

If lock was acquired it should return True, otherwise False.

_get_preset_data(preset_name: str) → dict

Gets preset’s runtime data eg. fail counters, times

Parameters:preset_name (string) – Preset name

_release_lock(name: str) → None

Unlocks presets, other VMgr instance will be able to manage it.

Parameters:

• name (string) – Lock name in particular preset name.
• preset_name (string) – Preset name

_set_preset_data(preset_name: str, data: dict) → None

Saves preset’s runtime data - fail counters, times

Parameters:

• preset_name (string) – Preset name
• data (dict) – Set of counters and other volatile data