Ansible ‘raw’ module – using escape characters in regex to perform ‘sed’ command

ansible

I want to use the raw module to run a 'sed' command which will contain escape characters.

- name: Search for prefix in file and replace all following text with addition
  raw: "sed 's/\({{ prefix }}\)\(.*\)/\1 {{ addition }}/g' {{ file }} > {{ file }}.test"

This, however complains with:

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

With the '^' pointing at the first '\' in the string. How to I include escape characters in this command without ansible trying to process them?

Best Answer

The task below works

- raw: 'sed --regexp-extended ''s/({{ prefix }})(.*)/\1 {{ addition }}/g'' {{ file }} > {{ file }}.test'

with variables

file: test
prefix: AAA
addition: XXX

gives

$ cat test
alsdjflaskdjfasn AAA fasdfasdfsadf

$ cat test.test 
alsdjflaskdjfasn AAA XXX

Modified regex from "^" till "$"

- raw: 'sed --regexp-extended ''s/^(.*)({{ prefix }})(.*)$/\1 {{ addition }}/g'' {{ file }} > {{ file }}.test2'

gives

$ cat test.test2
alsdjflaskdjfasn  XXX

Notes

Use 7.3.2. Single-Quoted Style
With sed --regexp-extended the parentheses don't have to be escaped.

Related Solutions

Using more advanced filters with ansible setup module

Sadly, this is not supported. From the online documentation:

The filter option filters only the first level subkey below ansible_facts.

As the ansible_interface fact is a first level subkey in the structure of the JSON document, the minimum you can access is something like:

# ansible localhost -m setup -a 'filter=ansible_p5p1'
localhost | success >> {
    "ansible_facts": {
        "ansible_p5p1": {
            "active": true,
            "device": "p5p1",
            "ipv4": {
                "address": "10.0.0.2",
                "netmask": "255.255.255.0",
                "network": "10.0.0.0"
            },
            "ipv6": [
                {
                    "address": "fd6c:xxxx:xxxx::2",
                    "prefix": "64",
                    "scope": "global"
                },
                {
                    "address": "fe80::xxxx:xxxx:xxxx:5a56",
                    "prefix": "64",
                    "scope": "link"
                }
           ],
            "macaddress": "xx:xx:xx:xx:xx:xx",
            "module": "foo",
            "mtu": 1500,
            "promisc": false,
            "type": "ether"
        }
    },
    "changed": false
}

If your systems have facter or ohai installed, you can access the same information from ansible:

# ansible localhost -m setup -a 'filter=facter_ipaddress_p5p1'
localhost | success >> {
    "ansible_facts": {
        "facter_ipaddress_p5p1": "10.0.0.2"
    },
    "changed": false
}

Ansible: setting hostname over inventory

You could accomplish this with host variables such that your ansible_hosts file has:

[controllers_test]
10.144.38.137   hostname_suffix=A
10.144.38.139   hostname_suffix=B

And then your playbook becomes:

---
- hosts: controllers_test
  gather_facts: no
  remote_user:  admin
  tasks:
    - name: Assign names to the Controllers
      raw:  "set hostname ctr-TEST-{{hostname_suffix|quote}}"

Best Answer

Related Solutions

Using more advanced filters with ansible setup module

Ansible: setting hostname over inventory

Related Topic