Using .bashrc with shell from ansible

0 - Create a test container

docker run -d --rm --name test centos:7 bash -c "while true; do sleep 2000; done"

1 - inventory.yml

---
all:
  hosts:
    test:
      ansible_connection: docker

2 - playbook.yml

---
- name: run bash function from shell
  hosts: test
  gather_facts: false

  tasks:
    - name: make sure function is in bashrc
      blockinfile:
        dest: ~/.bashrc
        block: |-
          my_test_func() {
            echo hello test func
          }

    - name: run the function from shell after sourcing .bashrc
      shell: source ~/.bashrc && my_test_func
      register: func_result

    - name: check result
      debug:
        var: func_result.stdout

3 - result

$ ansible --version
ansible 2.8.4
  config file = None
  configured module search path = ['/home/user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/dist-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.8 (default, Aug 20 2019, 17:12:48) [GCC 8.3.0]
  
$ ansible-playbook -i inventory.yml playbook.yml 

PLAY [run bash function from shell] *******************************************************************************************************************************************************************************

TASK [make sure function is in bashrc] ****************************************************************************************************************************************************************************
changed: [test]

TASK [run the function from shell after sourcing .bashrc] *********************************************************************************************************************************************************
changed: [test]

TASK [check result] ***********************************************************************************************************************************************************************************************
ok: [test] => {
    "func_result.stdout": "hello test func"
}

PLAY RECAP ********************************************************************************************************************************************************************************************************
test                       : ok=3    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0