How to pass variables via command line?

You can pass variables to an Ansible playbook via the command line using the -e or --extra-vars option. This allows you to define variables at runtime. Here’s how to do it:

Passing a Single Variable: You can pass a single variable like this:
```
ansible-playbook my-playbook.yml -e "http_port=80"
```
Passing Multiple Variables: You can pass multiple variables by separating them with spaces:
```
ansible-playbook my-playbook.yml -e "http_port=80 db_port=3306"
```
Passing Variables as a JSON String: You can also pass variables in JSON format:
```
ansible-playbook my-playbook.yml -e '{"http_port": 80, "db_port": 3306}'
```
Using a Variable File: If you have a file containing variables, you can include it using the @ symbol:
```
ansible-playbook my-playbook.yml -e @vars.yml
```
Combining Methods: You can combine command line variables with variable files:
```
ansible-playbook my-playbook.yml -e @vars.yml -e "http_port=80"
```

Using these methods, you can dynamically set variables for your Ansible playbooks when executing them from the command line.