ansible-dynamic-inventory

Generate ansible dynamic inventory from static inventory. Optionally, Replace the host list of ansible static inventory with ServiceAddress registered in consul service.

Assumed Use Case

• Dynamic inventory conversion from Static inventory
• Merge Dynamic inventory into Static inventory cf. gce.py(dynamic inventory) + group_vars(static inventory)
• In the service operated using Consul, inventory is dynamically generated without rewriting static inventory when host information changes dynamically, such as automatic failover
• Confirm the inventory structure with plantuml

References

Ansible inventory Ansible Dynamic Inventory Consul Catalog Service

Installation

$ yum install gcc python-devel openssl-devel python-pip
$ pip install --upgrade pip setuptools (optional)
$ pip install ansible-dynamic-inventory

Prerequisite of Replace with Consul Service

If the group name written in the ansible static inventory and the service name registered in the consul service are the same, the host name is replaced.

Usage

# Stand alone execution
$ ansible-dynamic-inventory --list

# Stand alone execution and specified config file
$ ansible-dynamic-inventory --list --config /path/to/config
# or Specify config file with environment variable
$ ANSIBLE_DYNAMIC_INVENTORY_CONFIG_PATH=/path/to/config ansible-dynamic-inventory --list

# As Ansible Dynamic Inventory execution
$ ansible-playbook --inventory ansible-dynamic-inventory /path/to/playbook.yml

# outut in platuml format
ansible-dynamic-inventory --plantuml

Configuration

# vi ansible_dynamic_inventory.ini

[ansible]
# If both static_inventory_path and dynamic_inventory_path are specified,
# merge dynamic_inventory into static_inventory
# Either static_inventory_path or dynamic_inventory_path must not be empty

# path to static inventory file or directory
static_inventory_path = /path/to/ansible_inventory
# path to dynamic inventory file
#dynamic_inventory_path = ./gce.py
dynamic_inventory_path =

[consul]
#url = http://localhost:8500/v1
url =

Stand alone execution example

ex. ansible:static_inventory_path = ${this repository}/sample_inventory

$ ansible-dynamic-inventory --list
{
  "all": {
    "hosts": [
      "10.10.10.12",
      "10.10.10.13",
      "10.10.10.14",
      "10.10.10.15",
      "10.10.10.11"
    ],
    "children": [
      "ungrouped",
      "_mysql_replication_config",
      "mysql_backup_storage"
    ],
    "vars": {
      "datacenter": "vagrant",
      "net_cidr": "10.10.10.0/24"
    }
  },
  "_mysql_replication_config": {
    "hosts": [
      "10.10.10.12",
      "10.10.10.13",
      "10.10.10.14",
      "10.10.10.15",
      "10.10.10.11"
    ],
    "children": [
      "mysql_replication_master",
      "mysql_replication_slave",
      "mysql_replication_backup",
      "mysql_failover"
    ],
    "vars": {
      "mysql_replication_user": "root",
      "mysql_master_host": "{{groups.mysql_replication_master[0]}}",
      "mysql_master_group_name": "mysql_replication_master",
      "mysql_version": "5.6.34",
      "mysql_replication_group_name": "single",
      "mysql_slave_group_name": "mysql_replication_slave"
    }
  },
  "_meta": {
    "hostvars": {
      "10.10.10.15": {},
      "10.10.10.14": {},
      "10.10.10.11": {},
      "10.10.10.13": {},
      "10.10.10.12": {
        "hostvar": "dummy"
      }
    }
  },
  "mysql_backup_storage": {
    "hosts": [
      "10.10.10.15"
    ],
    "vars": {
      "mysql_backup_target_host": "{{groups.mysql_replication_backup[0]}}",
      "mysql_backup_storage_cron_file": "../../../../varfiles/vagrant/mysql/backup_storage/mysql_backup"
    }
  },
  "mysql_replication_slave": {
    "hosts": [
      "10.10.10.13",
      "10.10.10.14"
    ]
  },
  "mysql_replication_backup": {
    "hosts": [
      "10.10.10.15"
    ]
  },
  "ungrouped": {},
  "mysql_failover": {
    "hosts": [
      "10.10.10.11"
    ],
    "vars": {
      "mysql_failover_config_file": "../../../../varfiles/vagrant/mysql/failover/config.yml"
    }
  },
  "mysql_replication_master": {
    "hosts": [
      "10.10.10.12"
    ]
  }
}

output in platuml format example

ex. ansible:static_inventory_path = ${this repository}/sample_inventory

- Ansible host information is converted in plantuml "object"
- Ansible group information is converted in plantuml "package"
- Ansible group variable information is converted in plantuml "class"

$ /usr/bin/ansible-dynamic-inventory --plantuml
@startuml

object 10.10.10.15
object 10.10.10.14
object 10.10.10.11
object 10.10.10.13
object 10.10.10.12 {
  "hostvar": "dummy"
}

package all {
  all_hosts - 10.10.10.12
  all_hosts - 10.10.10.13
  all_hosts - 10.10.10.14
  all_hosts - 10.10.10.15
  all_hosts - 10.10.10.11
  class all_vars
  all_children - ungrouped
  all_children - _mysql_replication_config
  all_children - mysql_backup_storage
}
class all_vars {
  "datacenter": "vagrant"
  "net_cidr": "10.10.10.0/24"
}
package _mysql_replication_config {
  _mysql_replication_config_hosts - 10.10.10.12
  _mysql_replication_config_hosts - 10.10.10.13
  _mysql_replication_config_hosts - 10.10.10.14
  _mysql_replication_config_hosts - 10.10.10.15
  _mysql_replication_config_hosts - 10.10.10.11
  class _mysql_replication_config_vars
  _mysql_replication_config_children - mysql_replication_master
  _mysql_replication_config_children - mysql_replication_slave
  _mysql_replication_config_children - mysql_replication_backup
  _mysql_replication_config_children - mysql_failover
}
class _mysql_replication_config_vars {
  "mysql_replication_user": "root"
  "mysql_master_host": "{{groups.mysql_replication_master[0]}}"
  "mysql_master_group_name": "mysql_replication_master"
  "mysql_version": "5.6.34"
  "mysql_replication_group_name": "single"
  "mysql_slave_group_name": "mysql_replication_slave"
}
package mysql_backup_storage {
  mysql_backup_storage_hosts - 10.10.10.15
  class mysql_backup_storage_vars
}
class mysql_backup_storage_vars {
  "mysql_backup_target_host": "{{groups.mysql_replication_backup[0]}}"
  "mysql_backup_storage_cron_file": "../../../../varfiles/vagrant/mysql/backup_storage/mysql_backup"
}
package mysql_replication_slave {
  mysql_replication_slave_hosts - 10.10.10.13
  mysql_replication_slave_hosts - 10.10.10.14
}
package mysql_replication_backup {
  mysql_replication_backup_hosts - 10.10.10.15
}
package ungrouped {}
package mysql_failover {
  mysql_failover_hosts - 10.10.10.11
  class mysql_failover_vars
}
class mysql_failover_vars {
  "mysql_failover_config_file": "../../../../varfiles/vagrant/mysql/failover/config.yml"
}
package mysql_replication_master {
  mysql_replication_master_hosts - 10.10.10.12
}

@enduml

License

MIT License