can't update php.ini file in Docker container

Question

I'm trying to set Magento2 on Docker with Nginx & PHP7.

I've added a custom php.ini file as recommended by the PHP7 Docker image. I can see from phpinfo.php that it's loading my php.ini file but none of my updates are there.

It should be:

memory_limit = 2G
max_execution_time = 800

I've checked the PHP container and I can see the php.ini file is there with the correct settings, or so I think?

$ docker exec -it mymagento2docker_php_1 /bin/bash 
# cat /usr/local/etc/php/php.ini                                                                                                                  
; This file is created automatically by the docker build

memory_limit = 2G
max_execution_time = 800

What am I doing wrong? Below are some more details, thanks in advance!

---

Docker Project

.
├── docker-compose.yml
├── index.php
├── magento2
│   ├── [DIRECTORIES & FILES OMMITED]
│                   
├── nginx
│   ├── Dockerfile
│   ├── default.conf
│   └── nginx.conf
├── output.txt
├── php
    ├── Dockerfile
    └── config
        └── php.ini

---

docker-compose.yml

nginx:
    build: ./nginx/
    ports:
        - 80:80
    links:
        - php
    volumes_from:
        - app

php:
    build: ./php/
    expose:
        - 9000
    links:
        - mysql
    volumes_from:
        - app

app:
    image: php:7.0-fpm
    volumes:
        - ./magento2:/var/www/html
    command: "true"

mysql:
    image: mysql:latest
    volumes_from:
        - data
    ports:
        - "3306:3306"        
    environment:
        MYSQL_ROOT_PASSWORD: mage2
        MYSQL_DATABASE: mage2
        MYSQL_USER: mage2
        MYSQL_PASSWORD: mage2 

data:
    image: mysql:latest
    volumes:
        - /var/lib/mysql
    command: "true"

phpmyadmin:
    image: phpmyadmin/phpmyadmin
    ports:
        - 8080:80
    links:
        - mysql
    environment:
        PMA_HOST: mysql    

---

php/Dockerfile

FROM php:7.0-fpm

# Install dependencies
RUN apt-get update \
  && apt-get install -y \
    cron \
    libfreetype6-dev \
    libicu-dev \
    libjpeg62-turbo-dev \
    libmcrypt-dev \
    libpng12-dev \
    libxslt1-dev

# Configure the gd library
RUN docker-php-ext-configure \
  gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/

# Install required PHP extensions
RUN docker-php-ext-install \
  gd \
  intl \
  mbstring \
  mcrypt \
  pdo_mysql \
  xsl \
  zip \
  soap

# Install the 2.4 version of xdebug that's compatible with php7
RUN pecl install -o -f xdebug-2.4.0

COPY config/php.ini /usr/local/etc/php/

---

## php/config/php.ini ##
; This file is created automatically by the docker build

memory_limit = 2G
max_execution_time = 800

UPDATE

I've tried restarting nginx with the below, but it did not work.

$ docker exec -it mymagento2docker_php_1 /bin/bash 
# /etc/init.d/nginx restart                                                                                                                       
bash: /etc/init.d/nginx: No such file or directory
# service nginx restart    
nginx: unrecognized service
# nginx -s reload          
bash: nginx: command not found
# exit
$ docker restart mymagento2docker_nginx_1
mymagento2docker_nginx_1

$ docker exec -it mymagento2docker_nginx_1 /bin/bash 
# /etc/init.d/nginx restart                                                                                                                                   
Restarting nginx: nginxross in ~/my-magento2-docker
$ docker-compose ps
            Name                          Command             State            Ports          
---------------------------------------------------------------------------------------------
mymagento2docker_app_1          true                          Exit 0                          
mymagento2docker_data_1         docker-entrypoint.sh true     Exit 0                          
mymagento2docker_mysql_1        docker-entrypoint.sh mysqld   Up       0.0.0.0:3306->3306/tcp 
mymagento2docker_nginx_1        nginx -g daemon off;          Exit 0                          
mymagento2docker_php_1          php-fpm                       Up       9000/tcp               
mymagento2docker_phpmyadmin_1   /run.sh phpmyadmin            Up       0.0.0.0:8080->80/tcp   
ross in ~/my-magento2-docker
$ docker-compose up -d
Starting mymagento2docker_app_1
Starting mymagento2docker_data_1
mymagento2docker_mysql_1 is up-to-date
mymagento2docker_phpmyadmin_1 is up-to-date
mymagento2docker_php_1 is up-to-date
Starting mymagento2docker_nginx_1
ross in ~/my-magento2-docker
$ docker exec -it mymagento2docker_nginx_1 /bin/bash 
# service nginx restart                                                                                                                                       
Restarting nginx: nginxross in ~/my-magento2-docker
$ docker-compose up -d
Starting mymagento2docker_app_1
Starting mymagento2docker_data_1
mymagento2docker_mysql_1 is up-to-date
mymagento2docker_phpmyadmin_1 is up-to-date
mymagento2docker_php_1 is up-to-date
Starting mymagento2docker_nginx_1
ross in ~/my-magento2-docker
$ docker exec -it mymagento2docker_nginx_1 /bin/bash 
# nginx -s reload                                                                                                                                             
2016/10/05 14:07:43 [notice] 12#12: signal process started
# 

Answer 1

Add a volumes: section to your php service in the docker-compose.yml file, map a local directory with a custom.ini file to /usr/local/etc/php/conf.d, and restart your container. Whatever valid settings in that file will override those from the main php.ini file. (Incidentally you can do the same with MySQL but not with Nginx).

This works in my own project:

php: volumes: - ./localpath/custom.ini:/usr/local/etc/php/conf.d/custom.ini