Where can I get a list of Ansible pre-defined variables?
I use this simple playbook:
---
# vars.yml
#
# Shows the value of all variables/facts.
#
# Example:
#
# ansible-playbook vars.yml -e 'hosts=localhost'
#
- hosts: localhost
tasks:
- fail: "You must specify a value for `hosts` variable - e.g.: ansible-playbook vars.yml -e 'hosts=localhost'"
when: hosts is not defined
- hosts: "{{ hosts }}"
tasks:
- debug: var=vars
- debug: var=hostvars[inventory_hostname]
There are 3 sources of variables in Ansible:
Variables gathered from facts. You can get them by running command:
ansible -m setup hostnameBuilt-in (pre-defined) Ansible variables (AKA 'magic' variables). They are documented in Ansible documentation: http://docs.ansible.com/playbooks_variables.html#magic-variables-and-how-to-access-information-about-other-hosts
Here is the list extracted from Ansible 1.9 documentation:- group_names
- groups
- inventory_hostname
- ansible_hostname
- inventory_hostname_short
- play_hosts
- delegate_to
- inventory_dir
- inventory_file
- Variables passed to ansible via command line. But obviously you know what they are
ansible -m setup hostname
Only gets the facts gathered by the setup module.
Gilles Cornu posted a template trick to list all variables for a specific host.
Template (later called dump_variables):
HOSTVARS (ANSIBLE GATHERED, group_vars, host_vars) :
{{ hostvars[inventory_hostname] | to_yaml }}
PLAYBOOK VARS:
{{ vars | to_yaml }}
Playbook to use it:
- hosts: all
tasks:
- template:
src: templates/dump_variables
dest: /tmp/ansible_variables
- fetch:
src: /tmp/ansible_variables
dest: "{{inventory_hostname}}_ansible_variables"
After that you have a dump of all variables on every host, and a copy of each text dump file on your local workstation in your tmp folder. If you don't want local copies, you can remove the fetch statement.
This includes gathered facts, host variables and group variables. Therefore you see ansible default variables like group_names, inventory_hostname, ansible_ssh_host and so on.
From the FAQ:
How do I see a list of all of the ansible_ variables?
Ansible by default gathers “facts” about the machines under management, and these facts can be accessed in playbooks and in templates. To see a list of all of the facts that are available about a machine, you can run the
setupmodule as an ad hoc action:ansible -m setup hostnameThis will print out a dictionary of all of the facts that are available for that particular host. You might want to pipe the output to a pager.This does NOT include inventory variables or internal ‘magic’ variables. See the next question if you need more than just ‘facts’.
Here is the output for my vagrant virtual machine called scdev:
scdev | success >> {
"ansible_facts": {
"ansible_all_ipv4_addresses": [
"10.0.2.15",
"192.168.10.10"
],
"ansible_all_ipv6_addresses": [
"fe80::a00:27ff:fe12:9698",
"fe80::a00:27ff:fe74:1330"
],
"ansible_architecture": "i386",
"ansible_bios_date": "12/01/2006",
"ansible_bios_version": "VirtualBox",
"ansible_cmdline": {
"BOOT_IMAGE": "/vmlinuz-3.2.0-23-generic-pae",
"quiet": true,
"ro": true,
"root": "/dev/mapper/precise32-root"
},
"ansible_date_time": {
"date": "2013-09-17",
"day": "17",
"epoch": "1379378304",
"hour": "00",
"iso8601": "2013-09-17T00:38:24Z",
"iso8601_micro": "2013-09-17T00:38:24.425092Z",
"minute": "38",
"month": "09",
"second": "24",
"time": "00:38:24",
"tz": "UTC",
"year": "2013"
},
"ansible_default_ipv4": {
"address": "10.0.2.15",
"alias": "eth0",
"gateway": "10.0.2.2",
"interface": "eth0",
"macaddress": "08:00:27:12:96:98",
"mtu": 1500,
"netmask": "255.255.255.0",
"network": "10.0.2.0",
"type": "ether"
},
"ansible_default_ipv6": {},
"ansible_devices": {
"sda": {
"holders": [],
"host": "SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 02)",
"model": "VBOX HARDDISK",
"partitions": {
"sda1": {
"sectors": "497664",
"sectorsize": 512,
"size": "243.00 MB",
"start": "2048"
},
"sda2": {
"sectors": "2",
"sectorsize": 512,
"size": "1.00 KB",
"start": "501758"
},
},
"removable": "0",
"rotational": "1",
"scheduler_mode": "cfq",
"sectors": "167772160",
"sectorsize": "512",
"size": "80.00 GB",
"support_discard": "0",
"vendor": "ATA"
},
"sr0": {
"holders": [],
"host": "IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)",
"model": "CD-ROM",
"partitions": {},
"removable": "1",
"rotational": "1",
"scheduler_mode": "cfq",
"sectors": "2097151",
"sectorsize": "512",
"size": "1024.00 MB",
"support_discard": "0",
"vendor": "VBOX"
},
"sr1": {
"holders": [],
"host": "IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)",
"model": "CD-ROM",
"partitions": {},
"removable": "1",
"rotational": "1",
"scheduler_mode": "cfq",
"sectors": "2097151",
"sectorsize": "512",
"size": "1024.00 MB",
"support_discard": "0",
"vendor": "VBOX"
}
},
"ansible_distribution": "Ubuntu",
"ansible_distribution_release": "precise",
"ansible_distribution_version": "12.04",
"ansible_domain": "",
"ansible_eth0": {
"active": true,
"device": "eth0",
"ipv4": {
"address": "10.0.2.15",
"netmask": "255.255.255.0",
"network": "10.0.2.0"
},
"ipv6": [
{
"address": "fe80::a00:27ff:fe12:9698",
"prefix": "64",
"scope": "link"
}
],
"macaddress": "08:00:27:12:96:98",
"module": "e1000",
"mtu": 1500,
"type": "ether"
},
"ansible_eth1": {
"active": true,
"device": "eth1",
"ipv4": {
"address": "192.168.10.10",
"netmask": "255.255.255.0",
"network": "192.168.10.0"
},
"ipv6": [
{
"address": "fe80::a00:27ff:fe74:1330",
"prefix": "64",
"scope": "link"
}
],
"macaddress": "08:00:27:74:13:30",
"module": "e1000",
"mtu": 1500,
"type": "ether"
},
"ansible_form_factor": "Other",
"ansible_fqdn": "scdev",
"ansible_hostname": "scdev",
"ansible_interfaces": [
"lo",
"eth1",
"eth0"
],
"ansible_kernel": "3.2.0-23-generic-pae",
"ansible_lo": {
"active": true,
"device": "lo",
"ipv4": {
"address": "127.0.0.1",
"netmask": "255.0.0.0",
"network": "127.0.0.0"
},
"ipv6": [
{
"address": "::1",
"prefix": "128",
"scope": "host"
}
],
"mtu": 16436,
"type": "loopback"
},
"ansible_lsb": {
"codename": "precise",
"description": "Ubuntu 12.04 LTS",
"id": "Ubuntu",
"major_release": "12",
"release": "12.04"
},
"ansible_machine": "i686",
"ansible_memfree_mb": 23,
"ansible_memtotal_mb": 369,
"ansible_mounts": [
{
"device": "/dev/mapper/precise32-root",
"fstype": "ext4",
"mount": "/",
"options": "rw,errors=remount-ro",
"size_available": 77685088256,
"size_total": 84696281088
},
{
"device": "/dev/sda1",
"fstype": "ext2",
"mount": "/boot",
"options": "rw",
"size_available": 201044992,
"size_total": 238787584
},
{
"device": "/vagrant",
"fstype": "vboxsf",
"mount": "/vagrant",
"options": "uid=1000,gid=1000,rw",
"size_available": 42013151232,
"size_total": 484145360896
}
],
"ansible_os_family": "Debian",
"ansible_pkg_mgr": "apt",
"ansible_processor": [
"Pentium(R) Dual-Core CPU E5300 @ 2.60GHz"
],
"ansible_processor_cores": "NA",
"ansible_processor_count": 1,
"ansible_product_name": "VirtualBox",
"ansible_product_serial": "NA",
"ansible_product_uuid": "NA",
"ansible_product_version": "1.2",
"ansible_python_version": "2.7.3",
"ansible_selinux": false,
"ansible_swapfree_mb": 766,
"ansible_swaptotal_mb": 767,
"ansible_system": "Linux",
"ansible_system_vendor": "innotek GmbH",
"ansible_user_id": "neves",
"ansible_userspace_architecture": "i386",
"ansible_userspace_bits": "32",
"ansible_virtualization_role": "guest",
"ansible_virtualization_type": "virtualbox"
},
"changed": false
}
The current documentation now has a complete chapter about Discovering variables: facts and magic variables.