PHP7 : install ext-dom issue

Question

I'm running laravel 5.4 on Ubuntu 16.04 server with PHP7. trying to install cviebrock/eloquent-sluggable package throw some error:

pish@let:/home/sherk/ftp/www$ sudo composer require cviebrock/eloquent-sluggable
Do not run Composer as root/super user! See https://getcomposer.org/root for details
Using version ^4.2 for cviebrock/eloquent-sluggable
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/php-code-coverage 4.0.7 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/php-code-coverage 4.0.7 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/php-code-coverage (installed at 4.0.7) -> satisfiable by phpunit/php-code-coverage[4.0.7].

  To enable extensions, verify that they are enabled in those .ini files:
    - /etc/php/7.0/cli/php.ini
    - /etc/php/7.0/cli/conf.d/10-mysqlnd.ini
    - /etc/php/7.0/cli/conf.d/10-opcache.ini
    - /etc/php/7.0/cli/conf.d/10-pdo.ini
    - /etc/php/7.0/cli/conf.d/20-calendar.ini
    - /etc/php/7.0/cli/conf.d/20-ctype.ini
    - /etc/php/7.0/cli/conf.d/20-exif.ini
    - /etc/php/7.0/cli/conf.d/20-fileinfo.ini
    - /etc/php/7.0/cli/conf.d/20-ftp.ini
    - /etc/php/7.0/cli/conf.d/20-gd.ini
    - /etc/php/7.0/cli/conf.d/20-gettext.ini
    - /etc/php/7.0/cli/conf.d/20-iconv.ini
    - /etc/php/7.0/cli/conf.d/20-json.ini
    - /etc/php/7.0/cli/conf.d/20-mbstring.ini
    - /etc/php/7.0/cli/conf.d/20-mcrypt.ini
    - /etc/php/7.0/cli/conf.d/20-mysqli.ini
    - /etc/php/7.0/cli/conf.d/20-pdo_mysql.ini
    - /etc/php/7.0/cli/conf.d/20-phar.ini
    - /etc/php/7.0/cli/conf.d/20-posix.ini
    - /etc/php/7.0/cli/conf.d/20-readline.ini
    - /etc/php/7.0/cli/conf.d/20-shmop.ini
    - /etc/php/7.0/cli/conf.d/20-sockets.ini
    - /etc/php/7.0/cli/conf.d/20-sysvmsg.ini
    - /etc/php/7.0/cli/conf.d/20-sysvsem.ini
    - /etc/php/7.0/cli/conf.d/20-sysvshm.ini
    - /etc/php/7.0/cli/conf.d/20-tokenizer.ini
  You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.

Installation failed, reverting ./composer.json to its original content.

I have no problem installing this package on local version of the app .

Answer 1

First of all, read the warning! It says do not run composer as root! Secondly, you're probably using Xammp on your local which has the required php libraries as default.

But in your server you're missing ext-dom. php-xml has all the related packages you need. So, you can simply install it by running:

sudo apt-get update
sudo apt install php-xml

Most likely you are missing mbstring too. If you get the error, install this package as well with:

sudo apt-get install php-mbstring

Then run:

composer update
composer require cviebrock/eloquent-sluggable