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--- ansible:ansible_variables [2021/08/25 22:37]
manu
+++ ansible:ansible_variables [2025/05/21 16:24] (current)
manu
@@ Line 1: / Line 1: @@
 ====== Ansible variables ======
-Understanding variable precedence
+===== Understanding variable precedence =====
 Ansible does apply variable precedence, and you might have a use for it. Here is the order of precedence from least to greatest (the last listed variables override all other variables):
@@ Line 29: / Line 29: @@
 In general, Ansible gives precedence to variables that were defined more recently, more actively, and with more explicit scope. Variables in the defaults folder inside a role are easily overridden. Anything in the vars directory of the role overrides previous versions of that variable in the namespace. Host and/or inventory variables override role defaults, but explicit includes such as the vars directory or an include_vars task override inventory variables.
+===== Example in a playbook =====
+Ex: yml file
+<code>
+- hosts: webservers
+  vars:
+    http_port: 80
+    base_path: http://ansibile.local/wiki
+    app_path: {{ base_path }}/{{ http_port }}
+</code>
+===== variables: facts =====
+Facts are variable collected each time you contact a client. It contains IP adresses, OS type, level, hardware....
+To improve you ansible command, you can use cache on server into /etc/ansible/ansible.cfg (here cache is valid for 1 hour)
+<code>
+[defaults]
+fact_caching = jsonfile
+fact_caching_timeout = 3600
+fact_caching_connection = /tmp/myfacts
+</code>
+You can call them on the ansible server by using the command (xml output):
+<cli prompt='#'>
+opensuse:~ # ansible -m setup localhost
+ localhost | SUCCESS => {
+    "ansible_facts": {
+        "ansible_all_ipv4_addresses": [
+            "10.1.3.22"
+        ],
+        "ansible_all_ipv6_addresses": [
+            "fe80::209a:12e0:e8a7:8ea"
+        ],
+        "ansible_apparmor": {
+            "status": "enabled"
+        },
+        "ansible_architecture": "x86_64",
+        "ansible_cmdline": {
+            "BOOT_IMAGE": "/boot/vmlinuz-4.12.14-lp151.28.91-default",
+        },
+        "ansible_date_time": {
+            "date": "2021-09-13",
+            "day": "13",
+            "epoch": "1631520866",
+            "hour": "10",
+            "minute": "14",
+            "month": "09",
+            "second": "26",
+            "time": "10:14:26",
+            "tz": "CEST",
+            "tz_offset": "+0200",
+            "weekday": "Monday",
+            "weekday_number": "1",
+            "weeknumber": "37",
+            "year": "2021"
+        },
+...
+       "ansible_distribution": "openSUSE Leap",
+        "ansible_distribution_file_parsed": true,
+        "ansible_distribution_file_path": "/etc/os-release",
+        "ansible_distribution_file_variety": "SUSE",
+        "ansible_distribution_major_version": "15",
+        "ansible_distribution_release": "1",
+        "ansible_distribution_version": "15.1",
+</cli>
+Example of facts on AIX
+<code>
+{
+    "_ansible_facts_gathered": true,
+    "ansible_all_ipv4_addresses": [
+        "10.10.10.100"
+    ],
+    "ansible_all_ipv6_addresses": [
+        "::1%1"
+    ],
+    "ansible_apparmor": {
+        "status": "disabled"
+    },
+    "ansible_architecture": "chrp",
+    "ansible_date_time": {
+...
+    },
+    "ansible_distribution": "AIX",
+    "ansible_distribution_major_version": "7",
+    "ansible_distribution_release": "2",
+    "ansible_distribution_version": "7.2",
+    "ansible_nodename": "myaixhost",
+    "ansible_os_family": "AIX",
+    "ansible_pkg_mgr": "yum",
+    "ansible_processor": "PowerPC_POWER8",
+    "ansible_processor_cores": 8,
+    "ansible_processor_count": 1,
+    "ansible_product_name": "IBM,8284-22A",
+    "ansible_product_serial": "21xxxxV",
+</code>
+Example on linux ppc64le
+<code>
+{
+    "_ansible_facts_gathered": true,
+    "ansible_all_ipv4_addresses": [
+        "10.x.x.x0"
+    ],
+    "ansible_all_ipv6_addresses": [
+        "fe80::5b6c:b599:xxx9:xxxc"
+    ],
+    "ansible_apparmor": {
+        "status": "disabled"
+    },
+    "ansible_architecture": "ppc64le",
+    "ansible_bios_date": "NA",
+    "ansible_bios_vendor": "NA",
+    "ansible_bios_version": "NA",
+    "ansible_board_asset_tag": "NA",
+    "ansible_board_name": "NA",
+    "ansible_board_serial": "NA",
+    "ansible_board_vendor": "NA",
+    "ansible_board_version": "NA",
+    "ansible_chassis_asset_tag": "NA",
+    "ansible_chassis_serial": "NA",
+    "ansible_chassis_vendor": "NA",
+    "ansible_chassis_version": "NA",
+    "ansible_cmdline": {
+        "BOOT_IMAGE": "/vmlinuz-4.18.0-240.el8.ppc64le",
+    "ansible_distribution": "CentOS",
+    "ansible_distribution_file_parsed": true,
+    "ansible_distribution_file_path": "/etc/redhat-release",
+    "ansible_distribution_file_variety": "RedHat",
+    "ansible_distribution_major_version": "8",
+    "ansible_distribution_release": "NA",
+    "ansible_distribution_version": "8.4",
+    "ansible_nodename": "mylnxhost",
+    "ansible_os_family": "RedHat",
+</code>
+==== How to Create and Use Custom Facts in Ansible ====
+Custom facts (local facts) are the variables which are declared on ansible managed host. Custom facts are declared in ini or json file in the /etc/ansible/facts.d directory on managed host. File names of custom facts must have .fact extension.
+https://www.linuxtechi.com/create-use-custom-facts-in-ansible/
+Get the value of a variable Ex: var1
+<cli prompt='#'>
+opensuse:~ # ansible -i "node2," all -e "var1=toto" -m debug -a 'msg={{ var1 }}'
+</cli>
+===== Ansible inventory =====
+<cli prompt='$'>
+$ ansible --version | grep 'config file'
+  config file = /home/tux/.ansible.cfg
+$ ansible-config dump --only-changed
+DEFAULT_BECOME(/home/tux/.ansible.cfg) = True
+DEFAULT_BECOME_METHOD(/home/tux/.ansible.cfg) = sudo
+DEFAULT_HOST_LIST(/home/tux/.ansible.cfg) = ['/home/tux/
+inventory']
+DEFAULT_REMOTE_USER(/home/tux/.ansible.cfg) = ansible
+</cli>
+List all hosts, use the keyword **all**. To specify all host not in a group use **ungrouped**
+<cli prompt='$'>
+$ ansible all --list-hosts
+  hosts (21):
+    green.example.com
+    blue.example.com
+.168.100.1
+.168.100.10
+    alpha.example.org
+    beta.example.org
+    www001.example.com
+    www002.example.com
+    www003.example.com
+    db-99-node.example.com
+    db-100-node.example.com
+    db-101-node.example.com
+</cli>
+List the group webservers
+<cli prompt='$'>
+$ ansible webservers --list-hosts
+  hosts (10):
+    alpha.example.org
+    beta.example.org
+.168.1.100
+.168.1.110
+    www001.example.com
+    www002.example.com
+    www003.example.com
+</cli>
+Print inventory in YML format
+<cli prompt='$'>
+$ ansible-inventory --list --yaml
+all:
+  children:
+    ungrouped:
+      hosts:
+.16.120.161: {}
+.16.120.185: {}
+.16.120.188: {}
+</cli>
+===== Custom variable =====
+==== Time / date ====
+<code>
+- hosts: test
+  vars:
+    time: "{{ lookup('pipe', 'date -d \"1 day ago\" +\"%Y%m%d\"') }}"
+</code>

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