Is it possible to change a variable's value in ansible? - sed

Question

I wrote a playbook that read a content of two files. The first one is responsible for holding switches interfaces dynamically that have the protocol CDP.
example.cdp:
0/0
14/0
The second one (.cfg), is a file the contains also dynamically a bunch of interfaces that I need to push to a device using the cisco command "shutdown" to test my master/backup environment. If the interfaces of the example.cdp are here, I need to remove them because I cannot lose the communication with this device since the management is in-band.
example.cfg:
interface FastEthernet0/0
shutdown
interface FastEthernet1/0
shutdown
interface FastEthernet2/0
shutdown
interface FastEthernet2/1
shutdown
...
interface FastEthernet14/0
shutdown
playbook:
- name: Looping file
debug:
msg: "{{ item }}"
register: items
with_file:
- ~/ANSIBLE/{{ inventory_hostname }}.cfg
- debug: var=items.results[0].item
- name: capturing interfaces with cdp
raw: egrep '[0-9]+\/[0-9]+ ' -o ~/ANSIBLE/{{ inventory_hostname }}.cdp
register: cdp
- debug: var=cdp.stdout_lines
- set_fact:
cdp: "{{cdp.stdout_lines}}"
- debug: var=cdp
- name: Removing interfaces with cdp
raw: sed 's/interface FastEthernet{{item}}//' ~/ANSIBLE/{{ inventory_hostname }}.cfg
with_items:
- "{{cdp}}"
register: items
- debug: var=items
- name: Applying The Shutdown Template
ios_config:
lines:
- "{{ items.results[0].item }}"
provider: "{{cli}}"
register: shut1
- debug: var=shut1
tags: shut1
running the playbook:
<169.255.0.1> EXEC sed 's/interface FastEthernet0/0 //' ~/ANSIBLE /169.255.0.1.cfg
failed: [169.255.0.1] (item=0/0 ) => {
"changed": true,
"failed": true,
"item": "0/0 ",
"rc": 1,
"stderr": "sed: -e expression #1, char 30: unknown option to `s'\n",
"stdout": "",
"stdout_lines": []
}
<169.255.0.1> EXEC sed 's/interface FastEthernet14/0 //' ~/ANSIBLE/169.255.0.1.cfg
failed: [169.255.0.1] (item=14/0 ) => {
"changed": true,
"failed": true,
"item": "14/0 ",
"rc": 1,
"stderr": "sed: -e expression #1, char 31: unknown option to `s'\n",
"stdout": "",
"stdout_lines": []
}
As you can see, the problem is the content of the var "cdp". The interfaces have the symbol "/", wich is use in "sed" command and I should backslashed this one to solve my problem using ansible. Is there a way to open a variable and make some regsub on it?

Answer 1

sed can use any character as the regex tokenizer, so solve your issue quickly, turn it into (for instance using # character):
sed 's#interface FastEthernet{{item}}##' ~/ANSIBLE/{{ inventory_hostname }}.cfg
I have the impression templating would be a better way to write your tasks though.