Ansible: create a function - function

Question

I found this page from answer number 4 by #cobbzilla useful to my use case.
Just want to ask if Ansible is capable to have a function that will handle this command:
2>&1 >> /tmp/debug.log
I have already applied this solution to my yml files and I was looking if the command can be wrapped on a function so that it will show much cleaner.
My Sample Ansible yml:
- name: Deploy
hosts: localhost
connection: local
gather_facts: false
tasks:
- name: perform 1st script
shell: bash -c "1st_script.sh 2>&1 >> /var/tmp/debug.log"
- name: perform 2nd script
shell: bash -c "2nd_script.sh 2>&1 >> /var/tmp/debug.log"
- name: perform 3rd script
shell: bash -c "3rd_script.sh 2>&1 >> /var/tmp/debug.log"

Answer 1

Preliminary note: I am answering your direct question below because this can be useful in other circumstances.
Meanwhile, in the ansible context, playing bash scripts and returning their output and error to a log file on the target is generally not a good idea. You will be left blind if something goes wrong, or if you want to analyze the output, as the module will return an empty stderr and stdout. You will have to rely on analyzing the log file later (and finding the correct output since you mix script output in there).
On an even wider level, you should use shell/command only when there is no other possibility to get the same job done using existing modules
If you don't mind writing some lines of python, a pretty easy and straight forward way to acheive your goal is to use a custom filter. The below example is quickNdirty. You will probably have to harden its code (escape command characters, check for specific errors...) but this should put you on track.
For the example, I am creating the filter in the filter_plugins folder adjacent to the demo playbook. If you need to distribute that filter across projects, search the ansible documentation to learn how to wrap that in a role or a collection.
In filter_plugins/shell_filters.py
def bash_n_log(command, log_file='/var/tmp/debug.log'):
"""Return a formatted string to play the script in bash and log its output"""
return f'bash -c "{command} 2>&1 >> {log_file}"'
class FilterModule(object):
"""collection of shell utility filters."""
def filters(self):
"""Return the filter list."""
return {
'bash_n_log': bash_n_log
}
Then the demo playbook.yml
- name: Custom shell filter demo
hosts: localhost
gather_facts: false
vars:
my_commands:
- echo Hello World
- ls -l /dev/null
tasks:
- name: Play my commands with my filter
shell: "{{ item | bash_n_log }}"
loop: "{{ my_commands }}"
- name: Same example with non default log file
shell: "{{ item | bash_n_log('/tmp/other.log') }}"
loop: "{{ my_commands }}"
- name: Get content of the log files
slurp:
path: "{{ item }}"
register: slurped_logs
loop:
- /var/tmp/debug.log
- /tmp/other.log
- name: Show log file content
debug:
msg: "{{ (item.content | b64decode).split('\n') }}"
loop: "{{ slurped_logs.results }}"
loop_control:
label: "{{ item.item }}"
gives:
$ ansible-playbook playbook.yml
PLAY [Custom shell filter demo] ********************************************************************************************************************************************************************************************************
TASK [Play my commands with my filter] *************************************************************************************************************************************************************************************************
changed: [localhost] => (item=echo Hello World)
changed: [localhost] => (item=ls -l /dev/null)
TASK [Same example with non default log file] ******************************************************************************************************************************************************************************************
changed: [localhost] => (item=echo Hello World)
changed: [localhost] => (item=ls -l /dev/null)
TASK [Get content of the log files] ****************************************************************************************************************************************************************************************************
ok: [localhost] => (item=/var/tmp/debug.log)
ok: [localhost] => (item=/tmp/other.log)
TASK [Show log file content] ***********************************************************************************************************************************************************************************************************
ok: [localhost] => (item=/var/tmp/debug.log) => {
"msg": [
"Hello World",
"crw-rw-rw- 1 root root 1, 3 Mar 27 12:06 /dev/null",
""
]
}
ok: [localhost] => (item=/tmp/other.log) => {
"msg": [
"Hello World",
"crw-rw-rw- 1 root root 1, 3 Mar 27 12:06 /dev/null",
""
]
}
PLAY RECAP *****************************************************************************************************************************************************************************************************************************
localhost : ok=4 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Answer 2

I just tried and tested this simple solution worked, I just added vars section witch points the variable to a command
- name: Deploy
hosts: localhost
connection: local
gather_facts: false
vars:
logger: "2>&1 >> /var/tmp/debug.log"
tasks:
- name: perform 1st script
shell: bash -c "1st_script.sh {{ logger }}"
- name: perform 2nd script
shell: bash -c "2nd_script.sh {{ logger }}"
- name: perform 3rd script
shell: bash -c "3rd_script.sh {{ logger }}"