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community.general/docs/docsite/rst/filter_guide_selecting_json_data.rst
Felix Fontein 2a7f9f28b9
Improve docsite extra docs (#7444)
* Improve markup.

* Improve filter and test guides by linking to plugins and using FQCNs more consistently.

* list_merge is an option, not the filter's name.

* Improve filter docs.
2023-10-30 21:54:58 +00:00

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..
Copyright (c) Ansible Project
GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
SPDX-License-Identifier: GPL-3.0-or-later
.. _ansible_collections.community.general.docsite.json_query_filter:
Selecting JSON data: JSON queries
---------------------------------
To select a single element or a data subset from a complex data structure in JSON format (for example, Ansible facts), use the :ansplugin:`community.general.json_query filter <community.general.json_query#filter>`. The :ansplugin:`community.general.json_query#filter` filter lets you query a complex JSON structure and iterate over it using a loop structure.
.. note:: You must manually install the **jmespath** dependency on the Ansible controller before using this filter. This filter is built upon **jmespath**, and you can use the same syntax. For examples, see `jmespath examples <http://jmespath.org/examples.html>`_.
Consider this data structure:
.. code-block:: yaml+jinja
{
"domain_definition": {
"domain": {
"cluster": [
{
"name": "cluster1"
},
{
"name": "cluster2"
}
],
"server": [
{
"name": "server11",
"cluster": "cluster1",
"port": "8080"
},
{
"name": "server12",
"cluster": "cluster1",
"port": "8090"
},
{
"name": "server21",
"cluster": "cluster2",
"port": "9080"
},
{
"name": "server22",
"cluster": "cluster2",
"port": "9090"
}
],
"library": [
{
"name": "lib1",
"target": "cluster1"
},
{
"name": "lib2",
"target": "cluster2"
}
]
}
}
}
To extract all clusters from this structure, you can use the following query:
.. code-block:: yaml+jinja
- name: Display all cluster names
ansible.builtin.debug:
var: item
loop: "{{ domain_definition | community.general.json_query('domain.cluster[*].name') }}"
To extract all server names:
.. code-block:: yaml+jinja
- name: Display all server names
ansible.builtin.debug:
var: item
loop: "{{ domain_definition | community.general.json_query('domain.server[*].name') }}"
To extract ports from cluster1:
.. code-block:: yaml+jinja
- name: Display all ports from cluster1
ansible.builtin.debug:
var: item
loop: "{{ domain_definition | community.general.json_query(server_name_cluster1_query) }}"
vars:
server_name_cluster1_query: "domain.server[?cluster=='cluster1'].port"
.. note:: You can use a variable to make the query more readable.
To print out the ports from cluster1 in a comma separated string:
.. code-block:: yaml+jinja
- name: Display all ports from cluster1 as a string
ansible.builtin.debug:
msg: "{{ domain_definition | community.general.json_query('domain.server[?cluster==`cluster1`].port') | join(', ') }}"
.. note:: In the example above, quoting literals using backticks avoids escaping quotes and maintains readability.
You can use YAML `single quote escaping <https://yaml.org/spec/current.html#id2534365>`_:
.. code-block:: yaml+jinja
- name: Display all ports from cluster1
ansible.builtin.debug:
var: item
loop: "{{ domain_definition | community.general.json_query('domain.server[?cluster==''cluster1''].port') }}"
.. note:: Escaping single quotes within single quotes in YAML is done by doubling the single quote.
To get a hash map with all ports and names of a cluster:
.. code-block:: yaml+jinja
- name: Display all server ports and names from cluster1
ansible.builtin.debug:
var: item
loop: "{{ domain_definition | community.general.json_query(server_name_cluster1_query) }}"
vars:
server_name_cluster1_query: "domain.server[?cluster=='cluster2'].{name: name, port: port}"
To extract ports from all clusters with name starting with 'server1':
.. code-block:: yaml+jinja
- name: Display all ports from cluster1
ansible.builtin.debug:
msg: "{{ domain_definition | to_json | from_json | community.general.json_query(server_name_query) }}"
vars:
server_name_query: "domain.server[?starts_with(name,'server1')].port"
To extract ports from all clusters with name containing 'server1':
.. code-block:: yaml+jinja
- name: Display all ports from cluster1
ansible.builtin.debug:
msg: "{{ domain_definition | to_json | from_json | community.general.json_query(server_name_query) }}"
vars:
server_name_query: "domain.server[?contains(name,'server1')].port"
.. note:: while using ``starts_with`` and ``contains``, you have to use ``to_json | from_json`` filter for correct parsing of data structure.