How do I pass username and password while using Ansible Git module?

You can use something like this:

---
- hosts: all 
  gather_facts: no
  become: yes
  tasks:
    - name: install git package
      apt:
        name: git

    - name: Get updated files from git repository 
      git: 
        repo: "https://{{ githubuser | urlencode }}:{{ githubpassword | urlencode }}@github.com/privrepo.git"
        dest: /tmp

Note: {{ githubpassword | urlencode }} is used here, if your password also contains special characters @,#,$ etc

Then execute the following playbook:

ansible-playbook -i hosts github.yml -e "githubuser=arbabname" -e "githubpassword=xxxxxxx"

Note: Make sure you put the credentials in ansible vaults or pass it secure way

Improving on Arbab Nazar's answer, you can avoid exposing your password in the terminal by prompting for the credentials.

playbook.yml

--- 
- name: ANSIBLE - Shop Installation 
  hosts: '{{ target }}' 

  vars_prompt: 
    - name: "githubuser" 
      prompt: "Enter your github username" 
      private: no 
    - name: "githubpassword" 
      prompt: "Enter your github password" 
      private: yes 

  [...] 

And in the task reference the variables.

task.yml

- name: Get updated files from git repository 
  git:
    repo=https://{{ githubuser | urlencode }}:{{ githubpassword | urlencode }}@github.com/privrepo.git
    dest=/tmp

This will save the password as clear text in .git/config as url of remote "origin". The following task can be used to remove it.

- name: Ensure remote URL does not contain credentials
  git_config:
    name: remote.origin.url
    value: https://github.com/privrepo.git
    scope: local
    repo: /tmp

---

Taken from: Clone a private git repository with Ansible (using password prompt)

While Arbab's and F. Santiago's answers are correct, there is an important caveat: With https://{{ githubuser | urlencode }}:{{ githubpassword | urlencode }}@github.com/privrepo.git as the checkout URL, Git will store your password in plaintext inside the .git/ folder. This has been mentioned in a comment, but I think it deserves more attention. You might want to do away the Git module and use raw Git, e.g.:

vars_prompt: 
  - name: "githubuser" 
    prompt: "Enter your github username" 
    private: no 
  - name: "githubpassword" 
    prompt: "Enter your github password" 
    private: yes
tasks:
  - name: Git clone
    expect:
      command: git clone https://github.com/privrepo.git /tmp
      responses:
        Username: "{{ githubuser }}" # Username is a regex
        Password: "{{ githubpassword }}" # Password is a regex
    no_log: true

All of the answers here made it a bit too easy to leak the username/password into a log or error message, which seemed undesirable even if in my case it's a read-only deployment token.

Here's an alternative:

    - name: Configure Git credential storage
      command: "git config --global credential.helper store"
    - name: Populate the Git credential store
      template:
        src: files/git_credentials.j2
        dest: /home/appuser/.git-credentials
        owner: appuser
        group: appuser
        mode: u=rw,g=,o=
      no_log: true

The template looks like this:

https://{{ gitlab_username|urlencode }}:{{ gitlab_password|urlencode }}@gitlab.example.org