Summary

Class Structure

InventoryManager
—-> InventoryData

InventoryData
—-> Group
—-> Host

Ansible Hack

special host variables:

- inventory_file
- inventory_dir

Special Inventory

group_vars/, host_vars and var plugin

Pattern

pattern is used in playbook after hosts field so as to select hosts satisfied the pattern

supportted pattern:

raw
difference !
intersection &
subscript such as DataNode[10], DataNode[1:10], DataNode[01:10]
regular expression
regular expression began with ~ will ignore subscript

# select hosts that is NameNode and ZooKeeper but not HMaster
- hosts: NameNode:!HMaster:&ZooKeeper

# select the first 10 DataNode
- hosts: DataNode[10]

Playbook

- 'include' is taggable and conditional

Coding Skill

Design Skill

Include syntax is modeled by class PlaybookInclude. User can add condition, tags and vars to tasks and
include statement, so It's reasonable to create super class Conditional and Taggable for PalybookInclude

Usage Skill

Play descriptor

_name                = FieldAttribute(isa='string', default='', always_post_validate=True)

# TODO: generalize connection
_accelerate          = FieldAttribute(isa='bool', default=False, always_post_validate=True)
_accelerate_ipv6     = FieldAttribute(isa='bool', default=False, always_post_validate=True)
_accelerate_port     = FieldAttribute(isa='int', default=5099, always_post_validate=True)

# Connection
_fact_path           = FieldAttribute(isa='string', default=None)
_gather_facts        = FieldAttribute(isa='bool', default=None, always_post_validate=True)
_gather_subset       = FieldAttribute(isa='barelist', default=None, always_post_validate=True)
_gather_timeout      = FieldAttribute(isa='int', default=None, always_post_validate=True)
_hosts               = FieldAttribute(isa='list', required=True, listof=string_types, always_post_validate=True)

# Variable Attributes
_vars_files          = FieldAttribute(isa='list', default=[], priority=99)
_vars_prompt         = FieldAttribute(isa='list', default=[], always_post_validate=True)
_vault_password      = FieldAttribute(isa='string', always_post_validate=True)

# Role Attributes
_roles               = FieldAttribute(isa='list', default=[], priority=90)

# Block (Task) Lists Attributes
_handlers            = FieldAttribute(isa='list', default=[])
_pre_tasks           = FieldAttribute(isa='list', default=[])
_post_tasks          = FieldAttribute(isa='list', default=[])
_tasks               = FieldAttribute(isa='list', default=[])

# Flag/Setting Attributes
_force_handlers      = FieldAttribute(isa='bool', always_post_validate=True)
_max_fail_percentage = FieldAttribute(isa='percent', always_post_validate=True)
_serial              = FieldAttribute(isa='list', default=[], always_post_validate=True)
strategy: String
    linear: batch run
    free: each host run as fast as it can
_order               = FieldAttribute(isa='string', always_post_validate=True)

Question

Is fact cached in Inventory?
How to add timeout to fact gathering?
How to discover and clean the dead worker?

ansible investigation Summary