Combine attribute value using json_query in ansible - ansible

Question

I want to combine two attribute into single string separated by delimiter using the json_query in ansible
Sample data
{
"locations": [
{"name": "Seattle", "state": "WA"},
{"name": "New York", "state": "NY"},
{"name": "Bellevue", "state": "WA"},
{"name": "Olympia", "state": "WA"}
]
}
As shown in above data set i'm trying to filter the state "WA" and execpted output is:
[
"Seattle-WA",
"Bellevue-WA",
"Olympia-WA"
]
What i have tried as of now:
- debug:
msg: "{{ chart_list.HELM_CHARTS | json_query(\"[?state == 'WA'].{name:name,state:state}\") }}"
Output:
[
{
"name": "Seattle",
"state": "WA"
},
{
"name": "Bellevue",
"state": "WA"
},
{
"name": "Olympia",
"state": "WA"
}
]
Updated :
I was able to get the expected result by trial and error method and these are my findings:
[?state == 'WA'].[join('-',[name,state])][]
Output:
[
"Seattle-WA",
"Bellevue-WA",
"Olympia-WA"
]
Also if the input which you give is in unicode format, i suggest you to add to_json | from_json expressions as mentioned below:
selected_cities: "{{ test.locations| to_json | from_json | json_query(\"[?state == 'WA'].[join('-',[name,state])][]\") }}"
Using above expression will eliminate unicode error whil using the values or in any condition.
Check JMESPath site for more detail on the json_query, it was really helpful in resolving the issue.

Answer 1

For example
- debug:
msg: "{{ locations|
json_query('[?state == `WA`].[name,state]')|
map('join', '-')|list }}"
gives
msg:
- Seattle-WA
- Bellevue-WA
- Olympia-WA
The same result gives the task below using Jinja2 filters only
- debug:
msg: "{{ _names|zip(_states)|map('join', '-')|list }}"
vars:
_locations: "{{ locations|selectattr('state', 'eq', 'WA')|list }}"
_names: "{{ _locations|map(attribute='name')|list }}"
_states: "{{ _locations|map(attribute='state')|list }}"
json_query issue (fixed in 2.10 and later)
There is JMESPath join. Unfortunately
- debug:
msg: "{{ locations|
json_query('[].join(`-`, [name,state])') }}"
fails
msg: |-
JMESPathError in json_query filter plugin:
In function join(), invalid type for value: Seattle, expected one of: ['array-string'], received: "AnsibleUnicode"
to_json|from_json workaround
Quoting from json_query: Add examples for starts_with and contains #72821
data structure returned from register variables needs to be parsed using to_json | from_json in order to get a correct result. Fixes: ansible-collections/community.general#320
- debug:
msg: "{{ locations|to_json|from_json|
json_query('[].join(`-`, [name,state])') }}"
gives
msg:
- Seattle-WA
- New York-NY
- Bellevue-WA
- Olympia-WA

Answer 2

Just for the sake of a pure JMESPath way of doing it, as your trial and error solution still have an unneeded extra layer of complexity.
When you are doing
[?state == 'WA'].[join('-', [name, state])][]
You are creating an array [join('-', [name, state])] then flattening it [] for no reason.
You can just go to the solution with a shorter approach:
[?state == `WA`].join(`-`, [name, state])
Also mind that you can overcome the quotes in quotes (simple or double) complication for JMESPath queries using:
YAML multilines string: How do I break a string in YAML over multiple lines?
Backticks in your JMESPath query, as pointed in the documentation:
In the example above, quoting literals using backticks avoids escaping quotes and maintains readability.
Source: https://docs.ansible.com/ansible/latest/user_guide/playbooks_filters.html#selecting-json-data-json-queries
So you end up with (see note below if you are on an Ansible version < 2.10):
- debug:
msg: >-
{{ test.locations
| json_query('[?state == `WA`].join(`-`, [name, state])') }}
Please note: as raised by #Vladimir Botka on the versions prior to 2.10, you will be affected by this issue: https://github.com/ansible/ansible/issues/27299#issuecomment-331068246, forcing you to add a | to_json | from_json filter on the list.
Given the playbook:
- hosts: all
gather_facts: yes
tasks:
- debug:
msg: >-
{{ test.locations
| json_query('[?state == `WA`].join(`-`, [name, state])')
}}
vars:
test:
locations:
- name: Seattle
state: WA
- name: New York
state: NY
- name: Bellevue
state: WA
- name: Olympia
state: WA
This yields:
[
"Seattle-WA",
"Bellevue-WA",
"Olympia-WA"
]