132 lines
4.5 KiB
Markdown
132 lines
4.5 KiB
Markdown
reconstructed
|
|
=============
|
|
|
|
An Ansible plugin that can generate structured inventories programmatically.
|
|
|
|
This is a work in progress. I will make this README more useful later, provided
|
|
I just don't forget about this whole thing.
|
|
|
|
A `reconstructed` inventory executes a list of instructions that is read
|
|
from the `instructions` YAML field. Each instruction is a table with some
|
|
minimal control flow (`when`, `loop` and `run_once` keywords that work mostly
|
|
like their playbook cousins), an `action` field that contains the name of the
|
|
instruction to execute, and whatever fields are needed for the instruction.
|
|
|
|
The following actions are supported:
|
|
|
|
* `create_group` creates a group. The name of the group must be
|
|
provided using the `group` field, which must be a valid name or a
|
|
Jinja template that evaluates to a valid name. In addition, a
|
|
`parent` field containting the name of a single, existing parent
|
|
group (or a Jinja template generating the name) may be provided.
|
|
Finally, the `add_host` field may be set to a truthy value if the
|
|
current host must be added to the new group.
|
|
|
|
* `add_child` adds a child group to another group. The name of the
|
|
group being added must be provided in the `child` entry, while
|
|
the name of the parent must be provided in the `group` entry. Both
|
|
groups must exist. In addition, the names may be specified using
|
|
Jinja templates.
|
|
|
|
* `add_host` adds the current inventory host to a group. The name
|
|
of the group must be provided in the `group` entry. The group
|
|
must exist.
|
|
|
|
* `fail` causes the computations for the current host to stop with
|
|
an error. The error message may be specified in the `message`
|
|
entry; if present, it will be evaluated using Jinja.
|
|
|
|
* `set_fact` and `set_var` create a fact and a local variable,
|
|
respectively. Local variables will only be kept during the execution
|
|
of the script for the current host, while facts will be added to the
|
|
host's data. The `name` entry specifies the name of the fact or
|
|
variable while the `value` entry specifies its value. Both may be
|
|
Jinja templates.
|
|
|
|
* `stop` stops processing the list of instructions for the current
|
|
host.
|
|
|
|
In addition, the `block` can be used to repeat multiple instructions or make
|
|
them obey a single conditional. The instruction must include a `block` field,
|
|
containing the list of instructions which are part of the block. It may have
|
|
a `rescue` field, containing a list of instructions which will be executed on
|
|
error, and `always`, which may contain a list of instructions to execute in
|
|
all cases.
|
|
|
|
If the `vars` field is defined on an instruction, it must contain a table of
|
|
local variables to define. Their values are computed after the loop variable
|
|
is evaluated, but before the condition is. If these variables already existed,
|
|
their state will be saved and they will be restored after the instruction is
|
|
done executing. This is different from the core Ansible behaviour, which does
|
|
not evaluate the `vars` unless they are used.
|
|
|
|
A somewhat silly example can be found in the `example` directory. Trying to
|
|
execute it using `ansible-inventory --graph` results in the following output.
|
|
|
|
```
|
|
[WARNING]: reconstructed - error on host evil-vm: evil-vm is obviously evil,
|
|
skipping.
|
|
@all:
|
|
|--@managed:
|
|
| |--@by_environment:
|
|
| | |--@env_dev:
|
|
| | | |--vm00
|
|
| | | |--vm01
|
|
| | | |--vm02
|
|
| | | |--vm03
|
|
| | | |--vm04
|
|
| | | |--vm09
|
|
| | |--@env_prod:
|
|
| | | |--vm05
|
|
| | | |--vm06
|
|
| | | |--vm07
|
|
| | | |--vm08
|
|
| |--@by_failover_stack:
|
|
| | |--@fostack_1:
|
|
| | | |--vm00
|
|
| | | |--vm02
|
|
| | | |--vm05
|
|
| | | |--vm07
|
|
| | |--@fostack_2:
|
|
| | | |--vm01
|
|
| | | |--vm03
|
|
| | | |--vm06
|
|
| | | |--vm08
|
|
| | |--@no_failover:
|
|
| | | |--vm04
|
|
| | | |--vm09
|
|
| |--@by_network:
|
|
| | |--@net_dev:
|
|
| | | |--vm00
|
|
| | | |--vm01
|
|
| | | |--vm02
|
|
| | | |--vm03
|
|
| | | |--vm04
|
|
| | |--@net_infra:
|
|
| | | |--vm05
|
|
| | | |--vm06
|
|
| | | |--vm07
|
|
| | | |--vm08
|
|
| | | |--vm09
|
|
| |--@by_service:
|
|
| | |--@svc_ldap:
|
|
| | | |--@svcm_ldap_back:
|
|
| | | | |--@svcm_ldap_ro:
|
|
| | | | | |--vm02
|
|
| | | | | |--vm03
|
|
| | | | | |--vm07
|
|
| | | | | |--vm08
|
|
| | | | |--@svcm_ldap_rw:
|
|
| | | | | |--vm04
|
|
| | | | | |--vm09
|
|
| | | |--@svcm_ldap_front:
|
|
| | | | |--vm00
|
|
| | | | |--vm01
|
|
| | | | |--vm05
|
|
| | | | |--vm06
|
|
|--@reedmably_evil:
|
|
| |--evil-but-nicer-vm
|
|
|--@ungrouped:
|
|
| |--evil-vm
|
|
| |--localhost
|
|
```
|