Install SonataPageBundle with Symfony Flex

composer.json

{
    "type": "project",
    "license": "MIT",
    "require": {
        "php": "^7.0.8",
        "doctrine/doctrine-bundle": "^1.8",
        "jms/serializer-bundle": "^2.3",
        "sonata-project/doctrine-orm-admin-bundle": "^3.4",
        "sonata-project/page-bundle": "3.x-dev",
        "sonata-project/seo-bundle": "2.x-dev",
        "symfony/console": "^3.4",
        "symfony/flex": "^1.0",
        "symfony/framework-bundle": "^3.4",
        "symfony/lts": "^3",
        "symfony/yaml": "^3.4"
    },
    "require-dev": {
        "symfony/dotenv": "^3.4"
    },
    "config": {
        "preferred-install": {
            "*": "dist"
        },
        "sort-packages": true
    },
    "autoload": {
        "psr-4": {
            "App\\": "src/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "App\\Tests\\": "tests/"
        }
    },
    "scripts": {
        "auto-scripts": {
            "cache:clear": "symfony-cmd",
            "assets:install --symlink --relative %PUBLIC_DIR%": "symfony-cmd"
        },
        "post-install-cmd": [
            "@auto-scripts"
        ],
        "post-update-cmd": [
            "@auto-scripts"
        ]
    },
    "conflict": {
        "symfony/symfony": "*"
    },
    "extra": {
        "symfony": {
            "allow-contrib": true
        }
    }
}

config\packages\cmf_routing_bundle.yaml

# Read the documentation: https://symfony.com/doc/master/cmf/bundles/routing/configuration.html
# Install phpcr stack before using this configuration
cmf_routing:
    chain:
        routers_by_id:
            #cmf_routing.dynamic_router: 200
            sonata.page.router: 150
            router.default: 100

config\packages\sonata_notification.yaml

sonata_notification:
    consumers:
        register_default: false
    admin:
        enabled: false

config\packages\sonata_page.yaml

twig:
    form_themes:
        - '@SonataCore/Form/datepicker.html.twig'

sonata_block:
    context_manager: sonata.page.block.context_manager
    default_contexts: [sonata_page_bundle]

sonata_admin:
    assets:
        extra_javascripts:
            - bundles/sonatapage/sonata-page.back.min.js
        extra_stylesheets:
            - bundles/sonatapage/sonata-page.back.min.css

sonata_page:
    slugify_service: sonata.core.slugify.cocur
    multisite: host
    use_streamed_response: false
    ignore_route_patterns:
        - ^(.*)admin(.*)   # ignore admin route, ie route containing 'admin'
        - ^_(.*)          # ignore symfony routes

    ignore_routes:
        - sonata_page_cache_esi
        - sonata_page_cache_ssi
        - sonata_page_js_sync_cache
        - sonata_page_js_async_cache
        - sonata_cache_esi
        - sonata_cache_ssi
        - sonata_cache_js_async
        - sonata_cache_js_sync
        - sonata_cache_apc

    ignore_uri_patterns:
        - ^/admin\/   # ignore admin route, ie route containing 'admin'

    page_defaults:
        homepage: # disable decoration for homepage, key - is a page route
            decorate: false

    default_template: default
    templates:
        default:
            path: '@SonataPage/layout.html.twig'
            name: 'default'
        2columns:
            path: '@SonataPage/2columns_layout.html.twig'
            name: '2 columns layout'
    direct_publication: '%kernel.debug%'

    catch_exceptions:
        not_found: [404]    # render 404 page with "not_found" key (name generated: _page_internal_error_{key})
        fatal:     [500]    # so you can use the same page for different http errors or specify specific page for each error

    class:
        block: 'App\Entity\SonataPageBlock'
        page: 'App\Entity\SonataPagePage'
        site: 'App\Entity\SonataPageSite'
        snapshot: 'App\Entity\SonataPageSnapshot'

config\routes\sonata_page.yaml

sonata_page_exceptions:
    resource: '@SonataPageBundle/Resources/config/routing/exceptions.xml'
    prefix: /

sonata_page_cache:
    resource: '@SonataPageBundle/Resources/config/routing/cache.xml'
    prefix: /

config\serializer\Entity.SonataPageBlock.xml

<?xml version="1.0" encoding="UTF-8"?>
<serializer>
    <class name="App\Entity\SonataPageBlock" exclusion-policy="all" xml-root-name="_block">
        <property xml-attribute-map="true" name="id" type="integer" expose="true" since-version="1.0" groups="sonata_api_read,sonata_api_write,sonata_search"/>
    </class>
</serializer>

config\serializer\Entity.SonataPagePage.xml

<?xml version="1.0" encoding="UTF-8"?>
<serializer>
    <class name="App\Entity\SonataPagePage" exclusion-policy="all" xml-root-name="_page">
        <property xml-attribute-map="true" name="id" type="integer" expose="true" since-version="1.0" groups="sonata_api_read,sonata_api_write,sonata_search"/>
    </class>
</serializer>

config\serializer\Entity.SonataPageSite.xml

<?xml version="1.0" encoding="UTF-8"?>
<serializer>
    <class name="App\Entity\SonataPageSite" exclusion-policy="all" xml-root-name="_site">
        <property xml-attribute-map="true" name="id" type="integer" expose="true" since-version="1.0" groups="sonata_api_read,sonata_api_write,sonata_search"/>
    </class>
</serializer>

config\serializer\Entity.SonataPageSnapshot.xml

<?xml version="1.0" encoding="UTF-8"?>
<serializer>
    <class name="App\Entity\SonataPageSnapshot" exclusion-policy="all" xml-root-name="_snapshot">
        <property xml-attribute-map="true" name="id" type="integer" expose="true" since-version="1.0" groups="sonata_api_read,sonata_api_write,sonata_search"/>
    </class>
</serializer>

docker-compose.override.yaml

version: '3.2'

services:
    mysql:
        networks:
          - default

    phpmyadmin:
        image: phpmyadmin/phpmyadmin
        ports:
          - 8080:80
        networks:
          - default
        environment:
            PMA_ARBITRARY: "1"
            PMA_HOST: "mysql"
            PMA_USER: "root"
            PMA_PASSWORD: "root"
        volumes:
          - /sessions

docker-compose.yaml

version: '3.2'

services:
    mysql:
        image: mysql:5.7
        ports:
            - "3306:3306"
        expose:
          - 3306
        environment:
            MYSQL_ROOT_PASSWORD: "root"
            MYSQL_DATABASE: "db_name"
            MYSQL_USER: "db_user"
            MYSQL_PASSWORD: "db_password"
        volumes:
            - database:/var/lib/mysql

volumes:
    database:

src\Entity\SonataPageBlock.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Sonata\PageBundle\Entity\BaseBlock;

/**
 * @ORM\Entity
 * @ORM\Table(name="page__block")
 */
class SonataPageBlock extends BaseBlock
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     * @var int
     */
    protected $id;

    public function getId()
    {
        return $this->id;
    }
}

src\Entity\SonataPagePage.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Sonata\PageBundle\Entity\BasePage;

/**
 * @ORM\Entity
 * @ORM\Table(name="page__page")
 */
class SonataPagePage extends BasePage
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     * @var int
     */
    protected $id;

    public function getId()
    {
        return $this->id;
    }
}

src\Entity\SonataPageSite.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Sonata\PageBundle\Entity\BaseSite;

/**
 * @ORM\Entity
 * @ORM\Table(name="page__site")
 */
class SonataPageSite extends BaseSite
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     * @var int
     */
    protected $id;

    public function getId()
    {
        return $this->id;
    }
}

src\Entity\SonataPageSnapshot.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Sonata\PageBundle\Entity\BaseSnapshot;

/**
 * @ORM\Entity
 * @ORM\Table(name="page__snapshot")
 */
class SonataPageSnapshot extends BaseSnapshot
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     * @var int
     */
    protected $id;

    public function getId()
    {
        return $this->id;
    }
}