Docker PHP ext enable command failing - php

Question

What is required to have docker-php-ext-... commands available? I am creating an Alpine image
FROM alpine:3.12
RUN apk update && \
# Add support for PHP7.4.
apk add --no-cache --repository http://dl-cdn.alpinelinux.org/alpine/edge/community \
php php7-fpm nginx composer git
....
# PHPIZE dependencies + xdebug
RUN apk add --no-cache autoconf file g++ gcc libc-dev make pkgconf re2c \
php7-pecl-xdebug \
&& docker-php-ext-install xdebug
...
But I am getting /bin/sh: docker-php-ext-install: not found.
How can I run the command?
Also, can apk add php7-pecl-xdebug replace installing pecl as a dependency and requiring the extension that way?

Answer 1

You are using vanilla alpine image.
docker-php-ext-* commands exist only in php-alpine image
For example, replace your FROM to something like:
FROM php:7.4-fpm-alpine

Answer 2

There are two problems.
As Dmitry said, you are not using the PHP image but the vanilla Alpine image.
You try to pack nginx and PHP into a single container.
When you want to orchestrate nginx and PHP, you should use docker-compose.
This is an example PHP+nginx docker-compose.yml:
version: '3.1'
services:
nginx:
restart: always
image: nginx:latest
volumes:
- ./html/:/var/www/html/:cached
ports:
- "80:80"
links:
- php
php:
restart: always
build:
dockerfile: Dockerfile
expose:
- 9000
volumes:
- ./:/var/www/:cached
And this is the PHP Dockerfile used:
FROM php:7.4-fpm-alpine
ENV COMPOSER_ALLOW_SUPERUSER 1
RUN docker-php-ext-install mysqli
RUN set -xe \
&& apk add --update \
icu \
&& apk add --no-cache --virtual .php-deps \
make \
&& apk add --no-cache --virtual .build-deps \
$PHPIZE_DEPS \
zlib-dev \
icu-dev \
g++ \
&& docker-php-ext-configure intl \
&& docker-php-ext-install intl \
&& docker-php-ext-enable intl \
&& { find /usr/local/lib -type f -print0 | xargs -0r strip --strip-all -p 2>/dev/null || true; } \
&& apk del .build-deps \
&& rm -rf /tmp/* /usr/local/lib/php/doc/* /var/cache/apk/*