Loop over facts in playbook

[Edgars]

Hi

I have some troubles to understand how to loop over facts in playbook. Suppose I have the following:

ansible node01 -m setup -a 'filter=ansible_devices'
SSH password:
SU password[defaults to SSH password]:
node01 | success >> {
    "ansible_facts": {
        "ansible_devices": {
            "sda": {
                "holders": [],
                "host": "Serial Attached SCSI controller: VMware PVSCSI SCSI Controller (rev 02)",
                "model": "Virtual disk",
                "partitions": {
                    "sda1": {
                        "sectors": "204800",
                        "sectorsize": 512,
                        "size": "100.00 MB",
                        "start": "2048"
                    },
                    "sda2": {
                        "sectors": "104650752",
                        "sectorsize": 512,
                        "size": "49.90 GB",
                        "start": "206848"
                    }
                },
                "removable": "0",
                "rotational": "1",
                "scheduler_mode": "noop",
                "sectors": "104857600",
                "sectorsize": "512",
                "size": "50.00 GB",
                "support_discard": "0",
                "vendor": "VMware"
            },
            "sdb": {
                "holders": [],
                "host": "Serial Attached SCSI controller: VMware PVSCSI SCSI Controller (rev 02)",
                "model": "Virtual disk",
                "partitions": {
                    "sdb1": {
                        "sectors": "10469376",
                        "sectorsize": 512,
                        "size": "4.99 GB",
                        "start": "16384"
                    }
                },
                "removable": "0",
                "rotational": "1",
                "scheduler_mode": "noop",
                "sectors": "10485760",
                "sectorsize": "512",
                "size": "5.00 GB",
                "support_discard": "0",
                "vendor": "VMware"
            },
            "sdc": {
                "holders": [],
                "host": "Serial Attached SCSI controller: VMware PVSCSI SCSI Controller (rev 02)",
                "model": "Virtual disk",
                "partitions": {},
                "removable": "0",
                "rotational": "1",
                "scheduler_mode": "noop",
                "sectors": "14680064",
                "sectorsize": "512",
                "size": "7.00 GB",
                "support_discard": "0",
                "vendor": "VMware"
            }
        }
    },
    "changed": false
}

So there are 3 disks: sda, sdb and sdc. Two of them has partitions, one does not. So I want to loop over all disks and check which disk have partitions and which does not have and then do something about it. I know I can do something like this:

{{ ansible_devices['sda']['partitions'] }}

But when I will run this playbook I will not know neither disk labels nor number of disks.

Any ideas?

Thanks

Edgars

[Jonathan Davila]

Hi Edgars,

You want to use ansible's with_dict method of looping. Here is an example of looping through that dict and then a sample conditional for it as well

# This is the sample with_dict loop
    - debug: msg="The device {{ item.key }} with these partitions {{ item.value.partitions }}"
      with_dict: ansible_devices

# This msg will only be printed on the condition that a device has no partitions
    - debug: msg="The device {{ item.key }} has no partitions"
      with_dict: ansible_devices
      when: not item.value.partitions

Hopefully that helps you out.

[Edgars]

Great!! Thanks a lot!

Edgars

[DS]

Hey Guys,

I have the exact same issue where I need to find the drive that does not have any partitions on it.

so I have the exact same output from ansible_devices but I can't figure out how I load the output into ansible so I can run the filter on it

basically i need an output like /dev/sdb  or /dev/sdb or whatever the actual device name is that does not have partitions on it so I can then use that value in a subsequent - command: /usr/sbin//fdisk -l <device> for example - command: /usr/sbin/fdisk -l /dev/sdb

any help will be much appreciated

Thanks

[Jonathan Davila]

DS, 

Try this. 

This simple example will print the device name whenever the device has no partitions

- name: Loop facts
  hosts: localhost
  connection: local
  tasks:
    - name: looping
      debug:
        msg: "{{ item.key }}"
      when: "not {{ item.value.partitions }}"
      with_dict: ansible_devices

[DS]

Hey Jonathan,

Thanks for this.

I've figured it out using the previous examples and some more googleing :)

I got it to execute a shell command which i what I needed it to do:

  - shell: pvcreate /dev/"{{ item.key }}" 

    with_dict: ansible_devices

    when: not item.value.partitions and item.key != "sr0" and item.key != "fd0"

Thanks again