How to Filter A List By Its Attributes in an Ansible Playbook?
I’m going to show you a live Playbook with some simple Ansible code. I’m Luca Berton and welcome to today’s episode of Ansible Pilot.
selectattr filter in Ansible Playbook?
{{ users|selectattr("is_active") }}{{ users|selectattr("email", "none") }}
Today we’re talking about Ansible selectattr Jinja filter.
Filters a sequence of objects by applying a test to the specified attribute of each object, and only selecting the objects with the test succeeding.
If no test is specified, the attribute’s value will be evaluated as a boolean.
The two examples explain how-to for a specific attribute or value using a users list example.
Links
Playbook
How to filter a list by its attributes in an Ansible Playbook.
I’m going to use the selectattr filter to select only one information from Ansible System Information (Facts).
Specifically, I’m going to filter only for enabled features in a network interface (eth1).
code
---
- name: selectattr Playbook
hosts: all
gather_facts: true
tasks:
- name: all features
ansible.builtin.debug:
var: 'ansible_facts.eth1.features'
- name: filter enabled
ansible.builtin.debug:
msg: "{{ (ansible_facts.eth1.features | dict2items | selectattr('value', 'match', 'on') ) }}"
execution
ansible-pilot $ ansible-playbook -i virtualmachines/demo/inventory variables/selectattr.yml
PLAY [selectattr Playbook] ****************************************************************************
TASK [Gathering Facts] ****************************************************************************
ok: [demo.example.com]
TASK [all features] *******************************************************************************
ok: [demo.example.com] => {
"ansible_facts.eth1.features": {
"esp_hw_offload": "off [fixed]",
"esp_tx_csum_hw_offload": "off [fixed]",
"fcoe_mtu": "off [fixed]",
"generic_receive_offload": "on",
"generic_segmentation_offload": "on",
"highdma": "off [fixed]",
"hw_tc_offload": "off [fixed]",
"l2_fwd_offload": "off [fixed]",
"large_receive_offload": "off [fixed]",
"loopback": "off [fixed]",
"netns_local": "off [fixed]",
"ntuple_filters": "off [fixed]",
"receive_hashing": "off [fixed]",
"rx_all": "off",
"rx_checksumming": "off",
"rx_fcs": "off",
"rx_gro_hw": "off [fixed]",
"rx_gro_list": "off",
"rx_udp_gro_forwarding": "off",
"rx_udp_tunnel_port_offload": "off [fixed]",
"rx_vlan_filter": "on [fixed]",
"rx_vlan_offload": "on",
"rx_vlan_stag_filter": "off [fixed]",
"rx_vlan_stag_hw_parse": "off [fixed]",
"scatter_gather": "on",
"tcp_segmentation_offload": "on",
"tls_hw_record": "off [fixed]",
"tls_hw_rx_offload": "off [fixed]",
"tls_hw_tx_offload": "off [fixed]",
"tx_checksum_fcoe_crc": "off [fixed]",
"tx_checksum_ip_generic": "on",
"tx_checksum_ipv4": "off [fixed]",
"tx_checksum_ipv6": "off [fixed]",
"tx_checksum_sctp": "off [fixed]",
"tx_checksumming": "on",
"tx_esp_segmentation": "off [fixed]",
"tx_fcoe_segmentation": "off [fixed]",
"tx_gre_csum_segmentation": "off [fixed]",
"tx_gre_segmentation": "off [fixed]",
"tx_gso_list": "off [fixed]",
"tx_gso_partial": "off [fixed]",
"tx_gso_robust": "off [fixed]",
"tx_ipxip4_segmentation": "off [fixed]",
"tx_ipxip6_segmentation": "off [fixed]",
"tx_lockless": "off [fixed]",
"tx_nocache_copy": "off",
"tx_scatter_gather": "on",
"tx_scatter_gather_fraglist": "off [fixed]",
"tx_sctp_segmentation": "off [fixed]",
"tx_tcp6_segmentation": "off [fixed]",
"tx_tcp_ecn_segmentation": "off [fixed]",
"tx_tcp_mangleid_segmentation": "off",
"tx_tcp_segmentation": "on",
"tx_tunnel_remcsum_segmentation": "off [fixed]",
"tx_udp_segmentation": "off [fixed]",
"tx_udp_tnl_csum_segmentation": "off [fixed]",
"tx_udp_tnl_segmentation": "off [fixed]",
"tx_vlan_offload": "on [fixed]",
"tx_vlan_stag_hw_insert": "off [fixed]",
"vlan_challenged": "off [fixed]"
}
}
TASK [filter enabled] *****************************************************************************
ok: [demo.example.com] => {
"msg": [
{
"key": "tx_checksumming",
"value": "on"
},
{
"key": "tx_checksum_ip_generic",
"value": "on"
},
{
"key": "scatter_gather",
"value": "on"
},
{
"key": "tx_scatter_gather",
"value": "on"
},
{
"key": "tcp_segmentation_offload",
"value": "on"
},
{
"key": "tx_tcp_segmentation",
"value": "on"
},
{
"key": "generic_segmentation_offload",
"value": "on"
},
{
"key": "generic_receive_offload",
"value": "on"
},
{
"key": "rx_vlan_offload",
"value": "on"
},
{
"key": "tx_vlan_offload",
"value": "on [fixed]"
},
{
"key": "rx_vlan_filter",
"value": "on [fixed]"
}
]
}
PLAY RECAP ****************************************************************************************
demo.example.com : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
ansible-pilot $
Conclusion
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