How to install php-redis extension using the official PHP Docker image approach?

Question

I want to build my PHP-FPM image with php-redis extension based on the official PHP Docker image, for example, using this Dockerfile: php:5.6-fpm.

The docs

Answer 1

This works for alpine images:

RUN set -xe \
    && apk add --no-cache --update --virtual .phpize-deps $PHPIZE_DEPS \
    && pecl install -o -f redis  \
    && echo "extension=redis.so" > /usr/local/etc/php/conf.d/redis.ini \
    && rm -rf /usr/share/php \
    && rm -rf /tmp/* \
    && apk del  .phpize-deps

Edit: Added missing backslash