RH294 - ch08s02

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Guided Exercise: Troubleshooting Playbooks

In this exercise, you troubleshoot a playbook that has been given to you that does not work properly.

Outcomes

You should be able to troubleshoot and resolve issues in playbooks.

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 troubleshoot-playbook

Procedure 8.1. Instructions

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

[student@workstation ~]$ cd ~/troubleshoot-playbook/
[student@workstation troubleshoot-playbook]$

Create a file named ansible.cfg in the current directory. Configure the log_path parameter to write Ansible logs to the /home/student/troubleshoot-playbook/ansible.log file. Configure the inventory parameter to use the /home/student/troubleshoot-playbook/inventory file deployed by the lab script.
The completed ansible.cfg file should contain the following:
```
[defaults]
log_path = /home/student/troubleshoot-playbook/ansible.log
inventory = /home/student/troubleshoot-playbook/inventory
```

Run the samba.yml playbook. It fails with an error.

This playbook would set up a Samba server if everything were correct. However, the run fails because the random_var variable definition is not in double quotation marks. (If a colon is part of a value, the value must be protected by single or double quotation marks.) Read the error message to see how ansible-navigator run reports the problem. Notice that the variable random_var is assigned a value that contains a colon and is not protected by double quotation marks.

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml
ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  mapping values are not allowed in this context

The error appears to be in '/home/student/troubleshoot-playbook/samba.yml': line 8, column 30, but may be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

    install_state: installed
    random_var: This is colon: test
                             ^ here

Confirm that ansible-navigator has logged the error to the /home/student/troubleshoot-playbook/ansible.log file.

[student@workstation troubleshoot-playbook]$ tail ansible.log

The error appears to be in '/home/student/troubleshoot-playbook/samba.yml': line 8, column 30, but may be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

    install_state: installed
    random_var: This is colon: test
                             ^ here

Edit the samba.yml playbook and correct the error by adding double quotation marks to the entire value being assigned to random_var. The corrected version of the playbook contains the following content:
```
...output omitted...
  vars:
    install_state: installed
    random_var: "This is colon: test"
...output omitted...
```

Verify the syntax of the playbook using the --syntax-check option. The ansible-navigator command issues another error because there is too much white space indenting the last task, deliver samba config.

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml --syntax-check
ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  did not find expected '-' indicator

The error appears to be in '/home/student/troubleshoot-playbook/samba.yml': line 38, column 6, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:


     - name: Deliver samba config
     ^ here
Please review the log for errors.

Edit the playbook and remove the extra space for all lines in that task. The corrected playbook should appear as follows:

...output omitted...
    - name: Configure firewall for samba
      ansible.posix.firewalld:
        state: enabled
        permanent: true
        immediate: true
        service: samba

    - name: Deliver samba config
      ansible.builtin.template:
        src: samba.j2
        dest: /etc/samba/smb.conf
        owner: root
        group: root
        mode: 0644

Run the playbook using the --syntax-check option. The ansible-navigator command issues an error because the install_state variable is being used as a parameter in the install samba task and is not quoted. (If a Jinja2 expression is at the start of a value, the value must be protected by double quotation marks.)

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml --syntax-check
ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  found unacceptable key (unhashable type: 'AnsibleMapping')

The error appears to be in '/home/student/troubleshoot-playbook/samba.yml': line 14, column 17, but may be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

        name: samba
        state: {{ install_state }}
                ^ here
We could be wrong, but this one looks like it might be an issue with missing quotes. Always quote template expression brackets when they start a value. For instance:

    with_items:
      - {{ foo }}

Should be written as:

    with_items:
      - "{{ foo }}"
Please review the log for errors.

Edit the playbook and correct the install samba task. The reference to the install_state variable should be in double quotation marks. The resulting file should consist of the following content:
```
...output omitted...
  tasks:
    - name: Install samba
      ansible.builtin.dnf:
        name: samba
        state: "{{ install_state }}"
...output omitted...
```

Run the playbook using the --syntax-check option. It should not show any additional syntax errors.

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml --syntax-check
playbook: /home/student/troubleshoot-playbook/samba.yml

Run the playbook again. The debug install_state variable task returns the message The state for the samba service is installed. This task makes use of the ansible.builtin.debug module, and displays the value of the install_state variable. An error is also shown in the deliver samba config task, because no samba.j2 file is available in the /home/student/troubleshoot-playbook/ directory.

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml

PLAY [Install a samba server] **************************************************

TASK [Gathering Facts] *********************************************************
ok: [servera.lab.example.com]

TASK [Install samba] ***********************************************************
changed: [servera.lab.example.com]

TASK [Install firewalld] *******************************************************
ok: [servera.lab.example.com]

TASK [Debug install_state variable] ********************************************
ok: [servera.lab.example.com] => {
    "msg": "The state for the samba service is installed"
}

TASK [Start firewalld] *********************************************************
ok: [servera.lab.example.com]

TASK [Configure firewall for samba] ********************************************
changed: [servera.lab.example.com]

TASK [Deliver samba config] ****************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: If you are using a module and expect the file to exist on the remote, see the remote_src option
fatal: [servera.lab.example.com]: FAILED! => {"changed": false, "msg": "Could not find or access 'samba.j2'\nSearched in:\n\t/home/student/troubleshoot-playbook/templates/samba.j2\n\t/home/student/troubleshoot-playbook/samba.j2\n\t/home/student/troubleshoot-playbook/templates/samba.j2\n\t/home/student/troubleshoot-playbook/samba.j2 on the Ansible Controller.\nIf you are using a module and expect the file to exist on the remote, see the remote_src option"}

PLAY RECAP *********************************************************************
servera.lab.example.com    : ok=6    changed=2    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0
Please review the log for errors.

Edit the playbook and correct the src parameter in the deliver samba config task to be samba.conf.j2. The finished file should consist of the following content:

...output omitted...
    - name: Deliver samba config
      ansible.builtin.template:
        src: samba.conf.j2
        dest: /etc/samba/smb.conf
        owner: root
...output omitted...

Run the playbook again and all tasks should succeed.

[student@workstation troubleshoot-playbook]$ ansible-navigator run \
> -m stdout samba.yml

PLAY [Install a samba server] **************************************************

TASK [Gathering Facts] *********************************************************
ok: [servera.lab.example.com]

TASK [Install samba] ***********************************************************
ok: [servera.lab.example.com]

TASK [Install firewalld] *******************************************************
ok: [servera.lab.example.com]

TASK [Debug install_state variable] ********************************************
ok: [servera.lab.example.com] => {
    "msg": "The state for the samba service is installed"
}

TASK [Start firewalld] *********************************************************
ok: [servera.lab.example.com]

TASK [Configure firewall for samba] ********************************************
ok: [servera.lab.example.com]

TASK [Deliver samba config] ****************************************************
changed: [servera.lab.example.com]

TASK [Start samba] *************************************************************
changed: [servera.lab.example.com]

PLAY RECAP *********************************************************************
servera.lab.example.com    : ok=8    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

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 troubleshoot-playbook

This concludes the section.

Discuss Red Hat Enterprise Linux Automation with Ansible

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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.

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curl finds no route to host?

TPeters

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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?

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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.

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Revision: rh294-9.0-c95c7de