docker-compose-cookbooks/_builder/dc-env.sh

#!/bin/bash

process_env_vars() {
    local env_vars="$1"  # Accept the environment variables as the first parameter
    local APP_NAME="$(echo "$2" | tr '[:lower:]' '[:upper:]')"  # Convert app name to uppercase
    local results=()     # Array to collect results

    # Loop through each environment variable
    while IFS= read -r env_var; do
        # Split into name and value parts based on ':'
        var_name="${env_var%%:*}"  # Variable name
        var_value="${env_var#*:}"  # Variable value

        # Remove leading and trailing whitespace
        var_name=$(echo "$var_name" | xargs)
        var_value=$(echo "$var_value" | xargs)

        # Format the variable as required
        modified_var="${var_name}=\${${APP_NAME}_${var_name}:-${var_value}}"

        # Append the modified variable to results
        results+=("$modified_var")
    done <<< "$env_vars"

    # Output the results joined with new lines
    printf "%s\n" "${results[@]}" | sort
}