Why is my Docker Symfony project consuming so much memory?

Question

Description

I'm deploying my symfony project in prod. It works fine when I simply run docker-compose up. However I'm getting an issue with my deploy script and try accessing the web page in my navigator.

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 20480 bytes) in /var/www/redaph/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php on line 107

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 65536 bytes) in /var/www/redaph/vendor/composer/ClassLoader.php on line 444

What is weird is that, in my dockerfile I specify that I want my PHP_MEMORY_LIMIT to be at 256M. When I enter my container I see the following:

root@125de315edca:/var/www/redaph# php -i | grep memory_limit
memory_limit => 128M => 128M

Question

Why is my Docker Symfony project consuming so much memory?

If this is normal then: How do I correctly increase the PHP_MEMORY_LIMIT in my dockerfile?

deploy_prod.sh

#!/usr/bin/env bash
PROJECT=symfony
docker-compose up -d
docker exec redaph_symfony_1 php bin/console d:s:u --force
docker exec redaph_symfony_1 php bin/console c:c

Dockerfile:

FROM php:7.2-apache

ENV \
    APACHE_ADMIN_EMAIL=webmaster@localhost \
    PHP_TIME_ZONE=Europe/London \
    PHP_MEMORY_LIMIT=256M \
    PHP_UPLOAD_MAX_FILESIZE=32M \
    PHP_POST_MAX_SIZE=32M

ARG WORK_DIR

WORKDIR $WORK_DIR

COPY composer.lock $WORK_DIR
COPY composer.json $WORK_DIR

ENV COMPOSER_ALLOW_SUPERUSER 1

RUN apt-get update \
    && apt-get install -y -f apt-transport-https \
        libicu-dev \
        libfreetype6-dev \
        libjpeg62-turbo-dev \
        libpng-dev \
        libpq-dev \
        acl \
        cron \
        git \
        zip \
    && pecl install mongodb \
    && docker-php-ext-enable mongodb \
    && docker-php-ext-install \
        exif \
        gd \
        intl \
        opcache \
        pdo_mysql \
        pdo_pgsql \
        zip \
    && curl -sS https://getcomposer.org/installer | php \
    && mv composer.phar /usr/local/bin/composer \
    && composer install --no-dev --prefer-dist --optimize-autoloader --no-scripts \
    && chown -R www-data:www-data $WORK_DIR \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/* \
    && a2enmod rewrite \
    && service cron start

Answer 1

It seems more likely the problem is the code / configuration of your app. Docker may not need to be touched.

Depending on the handler you have configured, look into limiting monolog's buffer size (configuration code here -- search for buffer_size).

With Composer, run composer update locally in dev. When deploying, run composer install. update takes more memory than install in order to to resolve the dependency graph, assuming install has a composer.lock to work with.

It looks like that is what is being done based on the dockerfile you posted, but maybe something else is happening/interfering with that somewhere along the way. I would verify composer.lock contains what you think it does, just in case.

You can also try the flag memory_limit=-1 when you run composer:

php -d memory_limit=-1 composer install rest-of-args-here

If that's not enough, provide the version of Symfony you are using. Post your composer.json and Symfony configs related to monolog.

Answer 2

It would help knowing what's on those lines where the errors are happening.

Regarding how to change your limit: MY "right way", there's basically 2 I can think of:

• place a RUN in dockerfile with a one-liner edit, this should work https://serverfault.com/questions/96372/sed-php-ini-memory-limit.

• keep a php.ini file on local which will be copied to the container. To make docker copy it, under your volume key in docker-compose file do a line

  • /ini/location/on/local:/ini/location/container

  I find this one messy for your case, i'd only do it if the file needed lots/continuous editing, which isn't the case.

There's another option but it would require you to do it every time you build which isn't really useful:

• docker exec -it whatever bash

From there you just edit the file, assuming you've got the right tools (sed, vim, whatever you want).