[StackOverflow/docker] Docker and php-cli

### ROOT CAUSE The issue arises when running PHP scripts via `php-cli` in Docker containers. The root cause is that the default Docker image for PHP may not include necessary extensions or configurations, leading to errors like missing modules or incorrect runtime behavior. This is common when building custom Docker images for PHP applications without explicitly installing required extensions. ### CODE FIX To resolve this, create a Dockerfile that extends the official PHP image and installs the necessary extensions. For example, if the issue involves missing extensions like `mbstring` or `gd`, modify the Dockerfile as follows: ```Dockerfile FROM php:8.1-cli # Install system dependencies RUN apt-get update && apt-get install -y \ libzip-dev \ && docker-php-ext-install zip \ mbstring \ pdo pdo_mysql \ gd # Copy your PHP script and any required files COPY script.php /usr/src/php/app/ WORKDIR /usr/src/php/app CMD ["php", "script.php"] ``` **Steps:** 1. **Extend the PHP image**: Use the official PHP CLI image as a base. 2. **Install system dependencies**: Use `apt-get` to install packages required for PHP extensions. 3. **Enable extensions**: Use `docker-php-ext-install` to compile and enable extensions (e.g., `mbstring`, `pdo_mysql`, `gd`). 4. **Copy files**: Place your PHP script and dependencies into the container. 5. **Set the command**: Define the default command to execute your script. This ensures the Docker environment matches the expected runtime for PHP CLI scripts, resolving issues related to missing extensions or incorrect configurations.