ansible: how to parse output of an Oracle script (JSON_OBJECT) - ansible

Question

There is an Oracle script that runs this query:
select json_object (name, value) from v$parameter where lower(name) in ...
output of this script:
{"name":"processes","value":"1000"}
{"name":"sessions","value":"1522"}
{"name":"sga_target","value":"3221225472"}
{"name":"control_file_record_keep_time","value":"7"}
{"name":"db_block_size","value":"8192"}
{"name":"compatible","value":"19.0.0.0.0"}
...
I register stdout_lines during sql-script execution and then parse line by line:
- name: print fetched database parameters
debug:
msg: "{{ db_params_out.stdout_lines }}"
- name: create list of newdb parameters from fetched result
debug:
msg: "{{ item }}"
with_list: "{{ db_params_out.stdout_lines }}"
when: db_params_out.stdout_lines | length > 0
Output looks good to me:
TASK [db_standby_preinstall : print fetched database parameters] *********************************************************************************************
ok: [localhost -> ol79_1] => {
"msg": [
"",
"{\"name\":\"processes\",\"value\":\"1000\"}",
"{\"name\":\"sessions\",\"value\":\"1522\"}",
"{\"name\":\"sga_target\",\"value\":\"3221225472\"}",
"{\"name\":\"control_file_record_keep_time\",\"value\":\"7\"}",
"{\"name\":\"db_block_size\",\"value\":\"8192\"}",
"{\"name\":\"compatible\",\"value\":\"19.0.0.0.0\"}",
...
TASK [db_standby_preinstall : create list of newdb parameters from fetched result] ***************************************************************************
ok: [localhost -> ol79_1] => (item=) => {
"msg": ""
}
ok: [localhost -> ol79_1] => (item={'name': 'processes', 'value': '1000'}) => {
"msg": {
"name": "processes",
"value": "1000"
}
}
ok: [localhost -> ol79_1] => (item={'name': 'sessions', 'value': '1522'}) => {
"msg": {
"name": "sessions",
"value": "1522"
}
}
ok: [localhost -> ol79_1] => (item={'name': 'sga_target', 'value': '3221225472'}) => {
"msg": {
"name": "sga_target",
"value": "3221225472"
}
}
ok: [localhost -> ol79_1] => (item={'name': 'control_file_record_keep_time', 'value': '7'}) => {
"msg": {
"name": "control_file_record_keep_time",
"value": "7"
}
}
ok: [localhost -> ol79_1] => (item={'name': 'db_block_size', 'value': '8192'}) => {
"msg": {
"name": "db_block_size",
"value": "8192"
}
}
ok: [localhost -> ol79_1] => (item={'name': 'compatible', 'value': '19.0.0.0.0'}) => {
"msg": {
"name": "compatible",
"value": "19.0.0.0.0"
but I cannot address key/value of a fetched item, ansible fails with The error was: 'ansible.utils.unsafe_proxy.AnsibleUnsafeText object' has no attribute 'name' (or 'value') if i try to use item.name or item.value instead of item.
P.S. I can modify Oracle script and provide output in any format. I need to parse output and assign values to corresponding variables:
newdb_processes:1000
newdb_sessions:1522
etc...

Answer 1

Issue is solved. The problem was in the first line of stdout_lines which is empty but still passes via filter
when: db_params_out.stdout_lines | length > 0
I've removed this line but now I use "reject" filter in loop:
with_list: "{{ db_params_out.stdout_lines | reject('match', '^$') }}"
And it works now, no more empty output lines.
Thanks a lot user larsks who pointed me to a test-case with correct data to prove that his solution works properly.

Answer 2

You can pass each line through the from_json filter to get a structured object, like this:
- hosts: localhost
gather_facts: false
vars:
db_params_out:
stdout_lines:
- '{"name":"processes","value":"1000"}'
- '{"name":"sessions","value":"1522"}'
- '{"name":"sga_target","value":"3221225472"}'
- '{"name":"control_file_record_keep_time","value":"7"}'
- '{"name":"db_block_size","value":"8192"}'
- '{"name":"compatible","value":"19.0.0.0.0"}'
tasks:
- name: create list of newdb parameters from fetched result
debug:
msg: "{{ (item|from_json).name }}"
with_list: "{{ db_params_out.stdout_lines }}"
when: db_params_out.stdout_lines | length > 0
The above playbook outputs:
TASK [create list of newdb parameters from fetched result] **********************************************
ok: [localhost] => (item={'name': 'processes', 'value': '1000'}) => {
"msg": "processes"
}
ok: [localhost] => (item={'name': 'sessions', 'value': '1522'}) => {
"msg": "sessions"
}
ok: [localhost] => (item={'name': 'sga_target', 'value': '3221225472'}) => {
"msg": "sga_target"
}
ok: [localhost] => (item={'name': 'control_file_record_keep_time', 'value': '7'}) => {
"msg": "control_file_record_keep_time"
}
ok: [localhost] => (item={'name': 'db_block_size', 'value': '8192'}) => {
"msg": "db_block_size"
}
ok: [localhost] => (item={'name': 'compatible', 'value': '19.0.0.0.0'}) => {
"msg": "compatible"
}