How to strip quotes from a variable in Ansible? - regex

Question

I'm trying to get the value of a variable in a file into an Ansible variable so I can use it.
Here's what I've got:
- name: extract Unique Key
shell: "grep UNIQUE_KEY ../config.py | cut -d' ' -f 3"
register: command_output
- set_fact:
unique_key: x{{ command_output.stdout | regex_replace("^'", '') | regex_replace('^"', '') | regex_replace("'$", '') | regex_replace('"$', '') }}
- set_fact:
unique_key: "{{ unique_key | regex_replace('^x', '') }}"
- debug: var=unique_key
This works, but feels kludgy and looks ugly.
I've already tried to add sed to my original shell module, but I couldn't figure out how to get the quotes escaped correctly. I also couldn't figure out how to escape the regex_replace to get it to work in a single variable assignment.
Is there a simpler way to go from this:
"TEST"
or
'TEST'
to this:
TEST
in Ansible? (I'm also really new to Ansible so that's not helping either)
EDIT: After the answer by #Vladimir-Botka which I initially accepted, I found this issue:
If I don't strip the quotes and embed the variable in another variable, it keeps the quotes:
I need to use this value to construct a path:
vars:
service_location: "/opt/{{ unique_key }}-scheduler-service"
If I don't remove the quotes using my method above, The variable will contain the quotes as in this output of a debug statement:
ok: [fedorasvr1] => {
"service_location": "/opt/'TEST'-scheduler-service"
}

Answer 1

The short answer is "omit the first and the last character" if the quotes are part of the string
- set_fact:
unique_key: command_output.stdout[1:-1]
Internal interpretation is all the same. The quotes control the expansion of the variables. See 7.3.1. Double-Quoted Style and 7.3.2. Single-Quoted Style.
As an example. The play below
- hosts: localhost
vars:
var1: TEST
var2: 'TEST'
var3: "TEST"
tasks:
- template:
src: test.j2
dest: test
and the template
shell> cat test.j2
{{ var1 }}
{{ var2 }}
{{ var3 }}
give
shell> cat test
TEST
TEST
TEST
The quotes, if part of the string, can be removed. As an example the play below
- hosts: localhost
vars:
regex: "[`'\"]"
replace: ""
service_location: "/opt/{{ item|regex_replace(regex, replace)
}}-scheduler-service"
tasks:
- debug:
var: service_location
loop:
- '`TEST`'
- '"TEST"'
- '''TEST'''
- "'TEST'"
gives
ok: [localhost] => (item=`TEST`) =>
item: '`TEST`'
service_location: /opt/TEST-scheduler-service
ok: [localhost] => (item="TEST") =>
item: '"TEST"'
service_location: /opt/TEST-scheduler-service
ok: [localhost] => (item='TEST') =>
item: '''TEST'''
service_location: /opt/TEST-scheduler-service
ok: [localhost] => (item='TEST') =>
item: '''TEST'''
service_location: /opt/TEST-scheduler-service
It is also possible to use custom filter_plugins/string_filters.py which might be more convenient than complex escape constructs.
As an example. The play below
- hosts: localhost
vars:
replace: ""
service_location: "/opt/{{ item.0|string_replace(item.1, replace)
}}-scheduler-service"
tasks:
- debug:
var: service_location
with_together:
- - '`TEST`'
- '"TEST"'
- "'TEST'"
- - '`'
- '"'
- "'"
gives
ok: [localhost] => (item=[u'`TEST`', u'`']) =>
item:
- '`TEST`'
- '`'
service_location: /opt/TEST-scheduler-service
ok: [localhost] => (item=[u'"TEST"', u'"']) =>
item:
- '"TEST"'
- '"'
service_location: /opt/TEST-scheduler-service
ok: [localhost] => (item=[u"'TEST'", u"'"]) =>
item:
- '''TEST'''
- ''''
service_location: /opt/TEST-scheduler-service
FWIW, see other examples of filter_plugins.

Answer 2

Slightly different, but maybe related: I was getting unwanted quotes when using a lookup to initialize a variable which were then used in a "blockinfile" task. But it turns out the quotes were caused by the "blockinfile" and not the lookup, ie:
- name: set some variables
set_fact:
my_var: "{{ lookup('ini', 'my_var section=variables file=~/myconf.ini') }}"
- name: update myconf.cfg
blockinfile:
dest: myconf.cfg
state: present
create: true
owner: "{{user}}"
group: "{{user}}"
block: |
[Credentials]
access_key_id = blabla
secret_access_key = "{{my_var}}"
become: true
removing the quotes from this line worked:
secret_access_key = "{{my_var}}"