How to display ansible_host in console output even if an alias is defined at inventory level

[Julio Fernandez]

Hi everyone!

We currently use ansible_host variable and define an alias for the hosts we use as follows:

Inventory file

[my_jboss_servers]
jboss_server1 ansible_host=myhostnameABC
jboss_server2 ansible_host=myhostnameEFG
jboss_server3 ansible_host=myhostnameHIJ
jboss_server4 ansible_host=myhostnameKLM

The reason for this is because hosts might change from time to time and since we have host-specific variables and files, it's just easier to keep using the same alias so we don't have to change any file names in our repository however this also has a disadvantage as it might get confusing if we start removing and adding hosts since the ansible-playbook console output displays only the alias, not the actual host, see:

$ ansible-playbook myplaybook.yml -i inventory/my_inventory

PLAY [all] *********************************************************************

TASK [Gathering Facts] *********************************************************
ok: [jboss_server1]
ok: [jboss_server2]
ok: [jboss_server3]
ok: [jboss_server4]

TASK [Task 1 : Create home directory if it does not exist] *******************
ok: [jboss_server1]
ok: [jboss_server2]
ok: [jboss_server3]
ok: [jboss_server4]

My questions are:

1. Is there any ansible best-practice on how to handle this scenario?
2. Is there any way I can display the actual hostname, not the alias in the console output?

Thanks in advance for your help / guidance on this!

[Varun Chopra]

I think it's best to reserve ansible_host as the IP address as that remains constant. You can declare friendly names first that way:

jboss_1 ansible_host=10.0.0.10

Going by your method, your inventory will require a lot of upkeep because if the hostname changes, the inventory will break.

[Julio Fernandez]

Thanks, Varun!

Got it, but even so, imagine that we suddenly remove one of the so the inventory would initially look like this:

Inventory file

[my_jboss_servers]
jboss_server1 ansible_host=IP1
jboss_server3 ansible_host=IP3
jboss_server4 ansible_host=IP4

And if I run the playbook, I'll see something like this:

$ ansible-playbook myplaybook.yml -i inventory/my_inventory

PLAY [all] *********************************************************************

TASK [Gathering Facts] ******************************

***************************
ok: [jboss_server1]
ok: [jboss_server3]
ok: [jboss_server4]

TASK [Task 1 : Create home directory if it does not exist] *******************
ok: [jboss_server1]
ok: [jboss_server3]
ok: [jboss_server4]

Which I think might be confusing, initially as the first question would be: "what abour jboss_server2"? so I guess I'm trying to find a way to balance both, maintenance and clarity

Regards. 

[Russell Yorke]

Hey

Why not put a debug statement at the beginning of your play that outputs the ansible_hostname? That way you can a one-to-one mapping in your output and you can reference that to figure out what system each refers to? Just a thought.