WordPress mu-plugin that adds a WP CLI command to flush Cloudflare cache.

wpcli-flush-cloudflare-cache.php

<?php
/**
 * Plugin Name: WP CLI Flush Cloudflare Cache
 * Description: Register a WP CLI command to flush Cloudflare cache.
 * Author: Caleb Stauffer
 * Author URI: https://develop.calebstauffer.com
 * Plugin URI: https://gist.github.com/crstauf/07725140a81b88f331dc8c3c76d8bf1d
 */

if ( !defined( 'WP_CLI' ) || !WP_CLI )
	return;

if ( !function_exists( 'wpcli_flush_cloudflare_cache' ) ) {

	function wpcli_flush_cloudflare_cache( array $args, array $assoc_args ) : void {
		$zone_id       = WP_CLI\Utils\get_flag_value( $assoc_args, 'zone_id', constant( 'CLOUDFLARE_ZONE_ID' ) );
		$email_address = WP_CLI\Utils\get_flag_value( $assoc_args, 'email',   constant( 'CLOUDFLARE_EMAIL_ADDRESS' ) );
		$api_key       = WP_CLI\Utils\get_flag_value( $assoc_args, 'api_key', constant( 'CLOUDFLARE_API_KEY' ) );

		$undefined_count = 0;

		if ( empty( $zone_id ) ) {
			WP_CLI::debug( 'Cloudflare zone ID is undefined: define `CLOUDFLARE_ZONE_ID` PHP constant, or pass `zone_id` command argument.' );
			$undefined_count++;
		}

		if ( empty( $email_address ) ) {
			WP_CLI::debug( 'Cloudflare account email address is undefined: define `CLOUDFLARE_EMAIL_ADDRESS` PHP constant, or pass `email` command argument.' );
			$undefined_count++;
		}

		if ( empty( $api_key ) ) {
			WP_CLI::debug( 'Cloudflare API key is undefined: define `CLOUDFLARE_API_KEY` PHP constant, or pass `api_key` command argument.' );
			$undefined_count++;
		}

		if ( $undefined_count ) {
			$error_format = 'Cloudflare API required %s undefined.';
			$error = sprintf( $error_format, _n( 'parameter is', 'parameters are', $undefined_count ) );

			WP_CLI::error( $error );
		}

		$args = array(
			'headers' => array(
				'X-Auth-Email' => $email_address,
				'X-Auth-Key'   => $api_key,
				'Content-Type' => 'application/json',
			),
			'body' => wp_json_encode( array(
				'purge_everything' => true,
			) ),
		);

		$url = sprintf( 'https://api.cloudflare.com/client/v4/zones/%s/purge_cache', $zone_id );
		$response = wp_remote_post( $url, $args );

		if ( is_wp_error( $response ) ) {
			WP_CLI::debug( $response->get_error_message() );
			WP_CLI::error( 'Unable to connect to Cloudflare API.' );
		}

		$body = wp_remote_retrieve_body( $response );
		$body = json_decode( $body );

		if ( !$body->success ) {
			foreach ( $body->errors as $error )
				WP_CLI::debug( $error->message );

			WP_CLI::error( 'Cloudflare was unable to flush the cache.' );
		}

		WP_CLI::success( 'Cloudflare cache was flushed.' );
	}

	WP_CLI::add_command( 'cloudflare flush', 'wpcli_flush_cloudflare_cache' );

}