Installing XDebug in Docker

try this:

RUN pecl install xdebug && docker-php-ext-enable xdebug

I solved this by adding the following lines into my Docker file:

FROM php:7.0-apache

RUN a2enmod rewrite

RUN docker-php-ext-install pdo pdo_mysql

RUN yes | pecl install xdebug \
    && echo "zend_extension=$(find /usr/local/lib/php/extensions/ -name xdebug.so)" > /usr/local/etc/php/conf.d/xdebug.ini \
    && echo "xdebug.remote_enable=on" >> /usr/local/etc/php/conf.d/xdebug.ini \
    && echo "xdebug.remote_autostart=off" >> /usr/local/etc/php/conf.d/xdebug.ini


COPY php.ini /usr/local/etc/php/
COPY . /var/www/html/

Since xdebug version 3 there are breaking changes in config names.

RUN pecl install xdebug; \
    docker-php-ext-enable xdebug

and for configuration:

        { \
            echo "xdebug.mode=debug"; \
            echo "xdebug.start_with_request=yes"; \
            echo "xdebug.client_host=host.docker.internal"; \
            echo "xdebug.client_port=9000"; \
        } > /usr/local/etc/php/conf.d/docker-php-ext-xdebug.ini; \

More info: https://xdebug.org/docs/upgrade_guide

As of PHP 7.4 you only need this

RUN pecl install xdebug \
    && docker-php-ext-enable xdebug

And add this line to enable remote debugging

&& echo "xdebug.remote_enable=on" >> /usr/local/etc/php/conf.d/docker-php-ext-xdebug.ini \
&& echo "xdebug.remote_host = host.docker.internal" >> /usr/local/etc/php/conf.d/docker-php-ext-xdebug.ini \