RH294 - ch02s02

Bookmark this page

Guided Exercise: Building an Ansible Inventory

In this exercise, you create a new static inventory containing hosts and groups.

Outcomes

You should be able to create default and custom static inventories.

As the student user on the workstation machine, use the lab command to prepare your system for this exercise.

This command prepares your environment and ensures that all required resources are available.

[student@workstation ~]$ lab start playbook-inventory

Procedure 2.1. Instructions

Change into the /home/student/playbook-inventory/ directory.

[student@workstation ~]$ cd playbook-inventory
[student@workstation playbook-inventory]$

Create a custom static inventory file named inventory in the /home/student/playbook-inventory working directory.

Information about your four managed hosts is listed in the following table. Assign each host to multiple groups for management purposes based on the purpose of the host, the city where it is located, and the deployment environment to which it belongs.

In addition, groups for US cities (Raleigh and Mountain View) must be set up as children of the us group so that hosts in the United States can be managed as a group.

Table 2.1. Server Inventory Specifications

Host name	Purpose	Location	Environment
`servera.lab.example.com`	Web server	Raleigh	Development
`serverb.lab.example.com`	Web server	Raleigh	Testing
`serverc.lab.example.com`	Web server	Mountain View	Production
`serverd.lab.example.com`	Web server	London	Production

Create an inventory file in the /home/student/playbook-inventory working directory. Using the Server Inventory Specifications table as a guide, edit the inventory file so that it contains the following content:

[webservers]
server[a:d].lab.example.com

[raleigh]
servera.lab.example.com
serverb.lab.example.com

[mountainview]
serverc.lab.example.com

[london]
serverd.lab.example.com

[development]
servera.lab.example.com

[testing]
serverb.lab.example.com

[production]
serverc.lab.example.com
serverd.lab.example.com

[us:children]
raleigh
mountainview

Use variations of the ansible-navigator inventory command to verify the managed hosts and groups in the custom /home/student/playbook-inventory/inventory inventory file.

Important

Your ansible-navigator inventory command must include the -i option to specify the location of your inventory file, as shown in the following steps.

List all managed hosts in the inventory by using the ansible-navigator inventory -i inventory -m stdout --list command.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --list
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "development",
            "london",
            "production",
            "testing",
            "ungrouped",
            "us",
            "webservers"
        ]
    },
    "development": {
        "hosts": [
            "servera.lab.example.com"
        ]
    },
    "london": {
        "hosts": [
            "serverd.lab.example.com"
        ]
    },
    "mountainview": {
        "hosts": [
            "serverc.lab.example.com"
        ]
    },
    "production": {
        "hosts": [
            "serverc.lab.example.com",
            "serverd.lab.example.com"
        ]
    },
    "raleigh": {
        "hosts": [
            "servera.lab.example.com",
            "serverb.lab.example.com"
        ]
    },
    "testing": {
        "hosts": [
            "serverb.lab.example.com"
        ]
    },
    "us": {
        "children": [
            "mountainview",
            "raleigh"
        ]
    },
    "webservers": {
        "hosts": [
            "servera.lab.example.com",
            "serverb.lab.example.com",
            "serverc.lab.example.com",
            "serverd.lab.example.com"
        ]
    }
}

Graph all managed hosts in the inventory file that are not part of a group by running the ansible-navigator inventory -i inventory -m stdout --graph ungrouped command. No ungrouped managed hosts exist in this inventory file.
```
[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --graph ungrouped
@ungrouped:
```

Graph all managed hosts in the development group by using the ansible-navigator inventory -i inventory -m stdout --graph development command.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --graph development
@development:
  |--servera.lab.example.com

Graph all managed hosts in the testing group by using the ansible-navigator inventory -i inventory -m stdout --graph testing command.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --graph testing
@testing:
  |--serverb.lab.example.com

Graph all managed hosts in the production group by using the ansible-navigator inventory -i inventory -m stdout --graph production command.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --graph production
@production:
  |--serverc.lab.example.com
  |--serverd.lab.example.com

Graph all managed hosts in the us group by using the ansible-navigator inventory -i inventory -m stdout --graph us command.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory -m stdout --graph us
@us:
  |--@mountainview:
  |  |--serverc.lab.example.com
  |--@raleigh:
  |  |--servera.lab.example.com
  |  |--serverb.lab.example.com

Run ansible-navigator inventory -i inventory in interactive mode. Browse groups and managed host entries in the inventory file.

Type :0 to browse groups. Type :1 to browse hosts. Type :q to exit ansible-navigator.

[student@workstation playbook-inventory]$ ansible-navigator inventory \
> -i inventory

  Title              Description
0│Browse groups      Explore each inventory group and group members members
1│Browse hosts       Explore the inventory with a list of all hosts

Finish

On the workstation machine, change to the student user home directory and use the lab command to complete this exercise. This step is important to ensure that resources from previous exercises do not impact upcoming exercises.

[student@workstation ~]$ lab finish playbook-inventory

This concludes the section.

Discuss Red Hat Enterprise Linux Automation with Ansible

Go to community

Red Hat Linux Automation with Ansible (RH294)

Haley_Ruccio

24 lip 2023

Learn how to automate Linux system administration tasks with Red Hat Ansible Automation PlatformRed Hat Enterprise Linux Automation with Ansible (RH294) is designed for Linux administrators and developers who need to automate repeatable and error-prone steps for system provisioning, configuration, application deployment, and orchestration. This course is based on Red Hat® Enterprise Linux® 9 and Red Hat Ansible Automation Platform 2.2.Course content summaryInstall Red Hat Ansible Automation Platform on control nodes.Create and update inventories of managed hosts and manage connections to them.Automate administration tasks with Ansible Playbooks and ad hoc commands.Write effective playbooks at scale.Protect sensitive data used by Ansible Automation Platform with Ansible Vault.Reuse code and simplify playbook development with Ansible Roles and Ansible Content Collections.Audience for this courseThis course is geared toward Linux system administrators, DevOps engineers, infrastructure automation engineers, and systems design engineers who are responsible for these tasks:Automating configuration managementEnsuring consistent and repeatable application deploymentProvisioning and deployment of development, testing, and production serversIntegrating with DevOps continuous integration/continuous delivery workflowsPrerequisites for this coursePass the Red Hat Certified System Administrator (RHCSA) exam (EX200), or demonstrate equivalent Red Hat Enterprise Linux knowledge and experience.Take our free assessment to gauge whether this offering is the best fit for your skills.

980

curl finds no route to host?

TPeters

23 lip 2023

I am doing the self-paced course RH294 . With two exercises (Ch.3 final Lab and Ch.4 lab exercise 2) I ran into this problem:after installing and starting a web service, from the classroom web termicaI I cannot reach servera.lab.example.com with curl: "No route to host". This despite the fact that I can ping it, open a shell to it, and install the package on it with Ansible.Anyone else have the same problem?What might be the cause?

1702

Welcome to the Red Hat Linux Automation with Ansible (RH294) group in the Red Hat Learning Community

cschunke

18 lip 2023

We are excited to launch a space dedicated to the Red Hat Training course Red Hat Linux Automation with Ansible! To gain the most value from this group - click the "Join Group" button in the upper right hand corner.We encourage group members to collaborate in this group to discuss topics, ask questions, share best practices and tips, provide course feedback, and share their accomplishments as it relates to RH294.Read more about Red Hat Linux Automation with Ansible here.

351

Revision: rh294-9.0-c95c7de