[SOLVED] Is it possible to change a variable's value in ansible?

Issue

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 "/", which 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?

Solution

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.

Answered By - guido

Answer Checked By - Robin (WPSolving Admin)