Docker PHP Image when using Redis extension exited on signal 2 (SIGINT) - php

Question

I have the following DockerFile and docker-compose.yml for an Laravel application. I have just added Redis today and this appeared in my terminal in the end of docker-compose up when I tried to connect and use Redis from PHP.
zinc_app | [23-Dec-2019 11:31:27] ALERT: oops, unknown child (32) exited on signal 2 (SIGINT). Please open a bug report (https://bugs.php.net).
zinc_app | [23-Dec-2019 11:31:27] ALERT: oops, unknown child (31) exited on signal 2 (SIGINT). Please open a bug report (https://bugs.php.net).
zinc_app | [23-Dec-2019 11:32:09] ALERT: oops, unknown child (20) exited on signal 9 (SIGKILL). Please open a bug report (https://bugs.php.net).
I am pretty sure the error came from the PHP Redis extension, because it didn't have the problem before. Have anyone encountered this problem before? Have I configured anything wrong?
I have tested this on another computer, but it didn't exhibit the same behavior. I have tried docker system prune -a and build and up again, but my computer still has the same problem.
As for the code I have run. I have run this in artisan tinker.
$redis = new Redis();
$redis->connect('zinc_redis', 6379);
$redis->get('1'); // The Oops message originated from this line.
Docker Compose:
version: '3.6'
services:
#PHP Service
zinc_app:
build:
context: .
dockerfile: Dockerfile
image: zinc/php
container_name: zinc_app
restart: unless-stopped
tty: true
environment:
SERVICE_NAME: zinc_app
SERVICE_TAGS: dev
working_dir: /var/www
volumes:
- ./:/var/www
- /tmp:/tmp #For CS Fixer
- ./php/local.ini:/usr/local/etc/php/conf.d/local.ini
networks:
- app-network
#Nginx Service
zinc_webserver:
image: nginx:alpine
container_name: zinc_webserver
restart: unless-stopped
tty: true
ports:
- "8080:80"
volumes:
- ./:/var/www
- ./nginx/conf.d/:/etc/nginx/conf.d/
networks:
- app-network
#Postgres Service
zinc_db:
image: postgres:12-alpine
container_name: zinc_db
restart: unless-stopped
tty: true
ports:
- "5432:5432"
environment:
POSTGRES_DB: zinc
POSTGRES_PASSWORD: admin
SERVICE_TAGS: dev
SERVICE_NAME: postgres
volumes:
- dbdata:/var/lib/postgresql
- ./postgres/init:/docker-entrypoint-initdb.d
networks:
- app-network
zinc_redis:
image: redis:5.0-alpine
container_name: zinc_redis
restart: unless-stopped
tty: true
ports:
- "6379:6379"
volumes:
- ./redis/redis.conf:/usr/local/etc/redis/redis.conf
- redisdata:/data
networks:
- app-network
#Docker Networks
networks:
app-network:
driver: bridge
#Volumes
volumes:
dbdata:
driver: local
redisdata:
driver: local
FROM php:7.4-fpm
# Switch to root user
USER root
# Set working directory
WORKDIR /var/www
# Add user for laravel application
RUN groupadd -g 1000 www
RUN useradd -u 1000 -ms /bin/bash -g www www
RUN chown www:www /var/www
# Copy composer
COPY --chown=www:www composer.json composer.lock /var/www/
# Install dependencies
RUN apt-get update && apt-get install --no-install-recommends -y \
build-essential \
libpq-dev \
libpng-dev \
libjpeg62-turbo-dev \
libfreetype6-dev \
locales \
libzip-dev \
jpegoptim optipng pngquant gifsicle \
vim \
unzip \
git \
curl
# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*
# Install extensions
RUN docker-php-ext-install pgsql pdo_pgsql zip exif pcntl
# Enable igbinary & PHP Redis ext using igbinary
RUN pecl install -o -f igbinary && y | pecl install -o -f redis && docker-php-ext-enable redis igbinary
RUN rm -rf /tmp/pear
# Install composer
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
COPY --chown=www:www . /var/www/
# Change current user to www
USER www
# Install packages
RUN composer global require hirak/prestissimo && composer install
# Expose port 9000 and start php-fpm server
EXPOSE 9000
CMD ["php-fpm"]