How to get the device name of a specified mount point with ansible facts?

Using Ansible facts I can get the list of "ansible_mounts":

"ansible_mounts": [
{
"block_available": 423698,
"block_size": 4096,
"block_total": 507604,
"block_used": 83906,
"device": "/dev/sdb1",
"fstype": "ext4",
"inode_available": 130999,
"inode_total": 131072,
"inode_used": 73,
"mount": "/boot",
"options": "rw",
"size_available": 1735467008,
"size_total": 2079145984,
"uuid": "b5cfa485-21d2-4e66-b3a3-80f250acf9d9"
},
{
"block_available": 42446481,
"block_size": 4096,
"block_total": 131007993,
"block_used": 88561512,
"device": "/dev/sdd1",
"fstype": "xfs",
"inode_available": 524243436,
"inode_total": 524287936,
"inode_used": 44500,
"mount": "/u01",
"options": "rw",
"size_available": 173860786176,
"size_total": 536608739328,
"uuid": "f34a9499-ca4e-4db6-801a-16efb72a629d"
},
{
"block_available": 3010686,
"block_size": 4096,
"block_total": 4095466,
"block_used": 1084780,
"device": "/dev/sdc1",
"fstype": "ext4",
"inode_available": 984674,
"inode_total": 1048576,
"inode_used": 63902,
"mount": "/",
"options": "rw",
"size_available": 12331769856,
"size_total": 16775028736,
"uuid": "829e9504-965b-4660-acc2-12d10d022a3c"
}
],

How I can get the value of device where mount value is "

Use json_query. For example
- set_fact:
my_device: "{{ ansible_mounts|json_query(query) }}"
vars:
query: "[?mount=='/'].device "
- debug:
var: my_device


gives
my_device:
- /dev/sdc1


To get the first element of the list only append the filter first
- set_fact:
my_device: "{{ ansible_mounts|json_query(query)|first }}"


StackExchange DevOps Q#9536, answer score: 6