2-adhoc

Section 1: Ad-hoc commands

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For our first exercise, we are going to run some ad-hoc commands to help you get a feel for how Ansible works. Ansible Ad-Hoc commands enable you to perform tasks on remote nodes without having to write a playbook. They are very useful when you simply need to do one or two things quickly, to many remote nodes.

Step 1:

To start, we will need to go to our Inventory. So click Inventories on the left panel, and then click the name of our Inventory Windows Workshop Inventory. Now that you are on the Inventory Details page, we will need to go select our Host. So click HOSTS.

Next to each host is a checkbox. Check the box next to each host you want to run an Ad-Hoc Command on. You will then see the RUN COMMANDS button become enabled. Click it now.

This will pop up the Execute Command window. From here is where we can run a single task against our hosts.

Let’s start with something really basic - pinging a host. The win_ping module makes sure our windows hosts are responsive. This is not a traditional ping, but actually verifying both connectivity and authentication to the host.

Fill out this form as follows

Key	Value	Note
Module	win_ping
Arguments		Intentionally blank
Limit		This will be pre-filled out for you with the hosts you selected
MACHINE CREDENTIAL	Student Account

Once you click LAUNCH you will be redirected to the Job log. Every job and action in Ansible Tower is recorded and stored. These logs can be auto-rotated and can also be exported automatically to another logging system such as Splunk or ELK.

The first part of the log shows you the details of the job. This includes information such as who launched the job, against what hosts, and when.

The second part of the job log shows you the actual output from the command. If your connection was successful, you should see a result such as this.

The results returned will be different depending on which module is used, as they all handle and deal with different data sets depending on the task. No matter which module is used, you will always see a color coded STATUS of either SUCCESS, FAILURE, CHANGED, or SKIPPING.

Step 2:

Now let’s see how we can run a PowerShell command and view the output using the win_shell module.

Let’s fill out the form again, but this time use the win_shell module to execute the Get-Service Powershell command.

Key	Value	Note
Module	win_shell
Arguments	Get-Service
MACHINE CREDENTIAL	Student Account

Launch the job and view the results. You will see that it returns a direct output of what the Powershell command returned. This data can be stored to a variable and directly parsed inside your Ansible playbook later on.

And run it one more time with the Get-Process Powershell command.

Key	Value	Note
Module	win_shell
Arguments	Get-Process
MACHINE CREDENTIAL	Student Account

Step 3:

We will now take a look at your Windows nodes configuration. The setup module queries the remote host for various data and returns that data as Ansible facts. This data is useful to determine things such as OS Versions, Hardware Configuration, and other data points. This can then be used in your playbook for all sorts of reasons such as determining whether a task should even run, or determining what the name of a package should be based upon the OS Version.

The setup module will run automatically at the beginning of every playbook, unless configured not to, so that this data is always available to your playbook.

Lets go ahead and run the setup module to look at the output. Fill out the EXECUTE COMMAND form again with this info.

Key	Value	Note
Module	setup
Arguments		Intentionally blank
MACHINE CREDENTIAL	Student Account

You will then see results like this

(Note: If you click the three dots shown on line 23 in the above output, you will see all the facts returned by the setup module.)

Step 4:

Now, let’s install IIS using the win_feature module. Our arguments parameter is going to get a little more complex now.

Key	Value	Note
Module	win_feature
Arguments	name=Web-Server state=present
MACHINE CREDENTIAL	Student Account

You will notice that the log text is now orange. This is to denote that a change was made on the system versus the green that shows that no changes were made earlier.

Step 5:

OK, IIS is installed now so let’s be certain it is started using the service module.

Key	Value	Note
Module	win_service
Arguments	name=W3Svc state=started
MACHINE CREDENTIAL	Student Account

Step 6:

Finally, let’s clean up after ourselves. First, stop the IIS service.

Key	Value	Note
Module	win_service
Arguments	name=W3Svc state=stopped
MACHINE CREDENTIAL	Student Account

Step 7:

Next, remove the IIS feature.

Key	Value	Note
Module	win_feature
Arguments	name=Web-Server state=absent
MACHINE CREDENTIAL	Student Account

And now reboot the host.

Key	Value	Note
Module	win_reboot
Arguments		Intentionally blank
MACHINE CREDENTIAL	Student Account

Note

The win_reboot module will cause the machine to reboot, and then will wait for it to come completely back up before finishing. This way, if you need to reboot the host in the middle of your playbook, the rest of the playbook will not fail because the host is inaccessible.

End Result

Ad-hoc commands may be useful to run once in a while. However, as automation continues to grow within an environment, they are used less and less often. In the IIS example above, this could have (should have) been written out in a playbook instead of executed through a laborious series of ad-hoc commands. This interaction with ad-hoc commands seems to mimic running individual commands from a CLI. Additional exercises will really make this clear.

Also, did you catch this? When a task is performed on a Windows server, Ansible is smart enough to know whether a reboot is required after executing that task. The below is part of the output of the command to remove the IIS feature. The output of this task can be used in subsequent tasks, like whether or not to reboot before continuing.

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