docker The DSN string could not be parsed with CakePHP - docker

Question

I'm configuring CakePHP application with Docker.
I'm new to Docker and this is my first docker-compose.
Dockerfile
FROM php:7.2-apache
LABEL maintainer="Anuj Sharma <contact#anujsh.in>"
# Enable Apache Rewrite + Expires Module
RUN a2enmod rewrite expires
# Install dependencies
RUN apt-get update && apt-get install -y \
libfreetype6-dev \
libjpeg62-turbo-dev \
libpng-dev \
libyaml-dev \
zlib1g-dev \
libicu-dev \
libpq-dev \
libmcrypt-dev \
mysql-client \
g++ \
git \
libzip-dev \
zip \
unzip \
&& rm -r /var/lib/apt/lists/* \
&& pecl install mcrypt-1.0.1 \
&& docker-php-ext-install opcache \
&& docker-php-ext-configure intl \
&& docker-php-ext-install intl \
&& docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
&& docker-php-ext-configure zip --with-libzip \
&& docker-php-ext-install zip \
&& docker-php-ext-configure pdo_mysql --with-pdo-mysql=mysqlnd \
&& docker-php-ext-install -j$(nproc) gd \
&& docker-php-ext-install mbstring pcntl pdo_mysql pdo_pgsql pgsql \
&& docker-php-ext-enable mcrypt \
&& docker-php-ext-enable intl
# Install composer
#RUN curl -sS https://getcomposer.org/installer | php -- --install -dir=/usr/bin/ --filename=composer
RUN curl -sS https://getcomposer.org/installer | php && mv composer.phar /usr/local/bin/composer
# set recommended PHP.ini settings
# see https://secure.php.net/manual/en/opcache.installation.php
RUN { \
echo 'opcache.memory_consumption=128'; \
echo 'opcache.interned_strings_buffer=8'; \
echo 'opcache.max_accelerated_files=4000'; \
echo 'opcache.revalidate_freq=2'; \
echo 'opcache.fast_shutdown=1'; \
echo 'opcache.enable_cli=1'; \
echo 'upload_max_filesize=128M'; \
echo 'post_max_size=128M'; \
echo 'extension=intl.so'; \
} > /usr/local/etc/php/conf.d/php-recommended.ini
RUN pecl install apcu \
&& pecl install yaml \
&& docker-php-ext-enable apcu yaml
# Set our application folder as an environment variable
ENV APP_HOME /var/www/html
# Change uid and gid of apache to docker user uid/gid
RUN usermod -u 1000 www-data && groupmod -g 1000 www-data
# Change the web_root to cakephp /var/www/html/webroot folder
RUN sed -i -e "s/html/html\/webroot/g" /etc/apache2/sites-enabled/000-default.conf
# Copy source files and run composer
COPY . $APP_HOME
# Install all PHP dependencies
RUN composer install --no-interaction
# Change ownership of our applications
RUN chown -R www-data:www-data $APP_HOME
NOTE: I have copied commands from different sources to generate above Dockerfile.
docker-compose.yml
version: "3.1"
# Define all services
services:
# Our service is called CakePHP ;-)
cakephp:
# We want to use the image which is build from our Dockerfile
build: .
# Apache is running on port 80 but we want to expose this to port 4000 on our local machine
ports:
- "4000:80"
# We depending on the mysql backend
depends_on:
- mysql
volumes:
- .:/var/www/html/
environment:
- SECURITY_SALT=070q78he40qfw475q0q7v0wt7vfqw7vw87qw8dpowe7rfpwq437
- DATABASE_URL=mysql
- MYSQL_USERNAME=root
- MYSQL_PASSWORD=root
- MYSQL_DATABASE=cakephp
mysql:
# We use the mysql base image, version 5.7
image: mysql:5.7
# We mount a datavolume to make sure we don't loose data
volumes:
- cap_mysql_data:/var/lib/mysql
# Setting some env vars to create the DB
environment:
- MYSQL_ROOT_PASSWORD=root
- MYSQL_DATABASE=cakephp
volumes:
cap_mysql_data:
When I run
docker-compose build
It all goes well. But when I run to migrate the migrations
docker-compose run cakephp bin/cake migrations migrate
It gives error as
Exception: The DSN string 'mysql' could not be parsed. in [/var/www/html/vendor/cakephp/cakephp/src/Core/StaticConfigTrait.php, line 292]
The app.php file of CakePHP have configuration for datasource
'username' => env('MYSQL_USERNAME', 'root'),
'password' => env('MYSQL_PASSWORD', ''),
'database' => env('MYSQL_DATABASE', 'cakephp'),
'url' => env('DATABASE_URL', null),

Answer 1

The DATABASE_URL environment variable is expected to hold a DSN (data source name) string, mysql isn't such a string, this is what a DSN looks like:
mysql://user:pass#localhost:3306/database?encoding=utf8&timezone=UTC&cacheMetadata=true
The parts are basically as follows:
<driver>://<username>:<password>#<host>:<port>/<database>?<options>
If you don't actually want to use a DSN, then do not specify the DATABASE_URL variable.
See also
Cookbook > Database Access & ORM > Database Basics > Configuration
API > \Cake\Datasource\ConnectionManager::parseDsn()