How does Ansible work against multiple managed nodes?
Ansible works against multiple managed nodes or “hosts” in your infrastructure at the same time, using a list or group of lists know as inventory. Once your inventory is defined, you use patterns to select the hosts or groups you want Ansible to run against.
How to manage multiple servers with Ansible ad hoc commands?
When running ad hoc commands with Ansible, you can target individual hosts, as well as any combination of groups, hosts and subgroups. For instance, this is how you would check connectivity for every host in a group named servers: ansible servers -i inventory -m ping You can also specify multiple hosts and groups by separating them with colons:
How to load host and group variable files in Ansible?
Host and group variable files must use YAML syntax. Valid file extensions include ‘.yml’, ‘.yaml’, ‘.json’, or no file extension. See YAML Syntax if you are new to YAML. Ansible loads host and group variable files by searching paths relative to the inventory file or the playbook file.
How to target a host in Ansible playbook?
For example, you can run a playbook that defines hosts: all on a single host by specifying -i 127.0.0.2, (note the trailing comma). This works even if the host you target is not defined in your inventory. You can also limit the hosts you target on a particular run with the –limit flag: ansible-playbook site.yml –limit datacenter2
Where are variables stored in Ansible inventory file?
In addition to storing variables directly in the inventory file, host and group variables can be stored in individual files relative to the inventory file (not directory, it is always the file). These variable files are in YAML format. Valid file extensions include ‘.yml’, ‘.yaml’, ‘.json’, or no file extension.
Which is the most common pattern in Ansible?
Common patterns ¶ Description Pattern (s) All hosts all (or *) One host host1 Multiple hosts host1:host2 (or host1,host2) One group webservers
How are variables merged and flattened in Ansible?
By default variables are merged/flattened to the specific host before a play is run. This keeps Ansible focused on the Host and Task, so groups don’t really survive outside of inventory and host matching. By default, Ansible overwrites variables including the ones defined for a group and/or host (see DEFAULT_HASH_BEHAVIOUR ).