How do I extract values from a width delimited table in Ansible? - parsing

Question

I'm trying to extract values from the result of an SQL command that is printed to stdout.
first second
29494060 23004496
29774383 22979864
I want to parse it into a data structure that looks something like this
[
{ first: 29494060, second: 23004496 },
{ first: 29774383, second: 22979864 }
]
So that I can access the values for each record like {{ item.first }} and {{ item.second }}.
I have been able to extract a single record by creating an object literal with values extracted with the regex_replace filter.
- set_fact:
items: { first: "{{ item | regex_replace('\\s*?(\\d+)\\s*?(\\d+)', '\\1') }}", second: "{{ item | regex_replace('\\s*?(\\d+)\\s*?(\\d+)', '\\2') }}" }
loop: '{{ command_out.stdout_lines }}'
This only keeps the result last line. I have not been able to create a list for each result. I have not been able to use list concatenation like items: "{{ items | default([]) + [{…}] }}" because of nested Jinja templates.
How do I extract a printed table of data into a list of objects?

Answer 1

Create keys. For example
- set_fact:
keys: "{{ command_out.stdout_lines[0].split() }}"
- debug:
var: keys
gives
"keys": [
"first",
"second"
]
then add the dictionaries, created by the filters dict and zip, to the list sql_list
- set_fact:
sql_list: "{{ sql_list|default([]) +
[dict(keys|zip(item.split()))] }}"
loop: "{{ command_out.stdout_lines[1:] }}"
- debug:
var: sql_list
gives
"sql_list": [
{
"first": "29494060",
"second": "23004496"
},
{
"first": "29774383",
"second": "22979864"
}
]
The task simplified by custom plugins gives the same result
- set_fact:
sql_list: "{{ command_out.stdout_lines[1:]|
map('string_split')|
map('list_dict_zip_rev', keys)|
list }}"
$ cat filter_plugins/string_filters.py
def string_split(s, *i):
if len(i) == 0:
return s.split()
elif len(i) == 1:
return s.split(i[0])
else:
return s.split(i[0], i[1])
def list_dict_zip_rev(l,k):
return dict((y,x) for x,y in zip(l,k))
class FilterModule(object):
''' Ansible filters.'''
def filters(self):
return {
'list_dict_zip_rev' : list_dict_zip_rev,
'string_split' : string_split
}