Why doesn't Ansible like my regexp?

[John Harmon]

 

As far as I can tell I have all of my quotes... it just doesn't seem to like my escaping... Adding verbosity didn't give me any useful information.

  - name: Sanitize vm.cfg step 2 of
      lineinfile:
        path: "{{ file }}"
        regexp: "{{ item.regexp }}"
        line: "{{ item.line }}"
        backrefs: "{{ item.backrefs }}"
      with_items:
        - { regexp: "^(vif.*'mac=)((\w{2}:){3})((\w{2}:?){3})(.+)'$", line: "\1\2AA:{{ 99 | random(start=10, step=1) }}:{{ 99 | random(start=10, step=1) }}\6": backrefs: yes }
        - { regexp: "(^uuid)(?:[=\s']+)'(.*)'.*$", line: "{{ newid.stdout }}", backrefs: no }
        - { regexp: "(^name)(?:[=\s']+)'(.*)'.*$", line: "{{ newid.stdout }}", backrefs: no }

Result:

ERROR! Syntax Error while loading YAML.
  found unknown escape character

The error appears to have been in '/etc/ansible/playbooks/one-offs/test.yml': line 46, column 37, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

      with_items:
        - { regexp: "^(vif.*'mac=)((\w{2}:){3})((\w{2}:?){3})(.+)'$", line: "\1\2AA:{{ 99 | random(start=10, step=1) }}:{{ 99 | random(start=10, step=1) }}\6": backrefs: yes }
                                    ^ here
We could be wrong, but this one looks like it might be an issue with
missing quotes.  Always quote template expression brackets when they
start a value. For instance:

    with_items:
      - {{ foo }}

Should be written as:

    with_items:
      - "{{ foo }}"

[Kai Stian Olstad]

On Monday, 5 November 2018 18:13:39 CET John Harmon wrote:
>
> As far as I can tell I have all of my quotes... it just doesn't seem to
> like my escaping... Adding verbosity didn't give me any useful information.
>
>
> - name: Sanitize vm.cfg step 2 of
> lineinfile:
> path: "{{ file }}"
> regexp: "{{ item.regexp }}"
> line: "{{ item.line }}"
> backrefs: "{{ item.backrefs }}"
> with_items:
> - { regexp: "^(vif.*'mac=)((\w{2}:){3})((\w{2}:?){3})(.+)'$", line: "\1\2AA:{{
> 99 | random(start=10, step=1) }}:{{ 99 | random(start=10, step=1) }}\6":
> backrefs: yes }
> - { regexp: "(^uuid)(?:[=\s']+)'(.*)'.*$", line: "{{ newid.stdout
> }}", backrefs: no }
> - { regexp: "(^name)(?:[=\s']+)'(.*)'.*$", line: "{{ newid.stdout
> }}", backrefs: no }
>
> Result:
> ERROR! Syntax Error while loading YAML.
> found unknown escape character

In my experience this is because of double quotes around regexp and line that contains backslash, it is treated as a string and do expand escapes.
You can avoid that by using single quotes instead, but then you need to escape the single quotes in you regexp.

What I do is avoid quotes all together, to do that you need to write your with_items in another style

with_items:
- regexp: ^(vif.*'mac=)((\w{2}:){3})((\w{2}:?){3})(.+)'$

line: \1\2AA:{{ 99 | random(start=10, step=1) }}:{{ 99 | random(start=10, step=1) }}\6
backrefs: yes
- regexp: (^uuid)(?:[=\s']+)'(.*)'.*$

line: "{{ newid.stdout }}"

backrefs: no
- regexp: (^name)(?:[=\s']+)'(.*)'.*$

line: "{{ newid.stdout }}"
backrefs: no


This should work and the double quotes in the line must be there since { after colon in yaml is treated as a dict.

--
Kai Stian Olstad

[John Harmon]

Thanks Kai!  That was the issue.  No complaints from Ansible now.