PHP 7.4 GD installed in dockerfile yet php reporting that imagecreatetruecolor is undefined

[glenelkinsdev]

I'm having a nightmare with the php 7.4 docker image and GD, i have installed GD with the best of my knowledge yet when i try to use imagecreatetruecolor it's an undefined function.

Here is my dockerfile (the part of it that's relevant anyway):

FROM php:7.4-fpm

RUN apt update

RUN apt-get install -y libzip-dev zip curl libpng-dev libonig-dev libjpeg-dev libfreetype6-dev
RUN docker-php-ext-configure gd --with-freetype --with-jpeg
RUN docker-php-ext-install -j$(nproc) mysqli pdo pdo_mysql zip gd mbstring exif iconv

RUN docker-php-ext-enable pdo_mysql zip gd

I'm not sure what else i'm supposed to do.

[tianon]

Hmm, I'm not able to reproduce -- I slightly modified your Dockerfile, but nothing material (combining apt-get update and apt-get install on the same line, combining configure and install on the same line, and ditching the redundant enable invocation):

FROM php:7.4-fpm

RUN apt-get update && apt-get install -y libzip-dev zip curl libpng-dev libonig-dev libjpeg-dev libfreetype6-dev

RUN docker-php-ext-configure gd --with-freetype --with-jpeg && docker-php-ext-install -j$(nproc) mysqli pdo pdo_mysql zip gd mbstring exif iconv

$ docker build --pull .
...
Successfully built a30055c5abc2
$ docker run -it --rm a30055c5abc2 php -a
Interactive shell

php > var_dump(imagecreatetruecolor(10, 10));
resource(1) of type (gd)