THE PHOTON SPHERE

Emacs editing in a Drupal Docker container

Posted September 6, 2019
Tags: Computer, Software, Linux, PHP, CMS, Server, Client, GUI, Web, Emacs, IDE, Docker, Drupal, HTML, CSS

Create a Drupal Docker image with support for Emacs editing set up (HTML, CSS, PHP files). With phpMyAdmin support. Under Debian Linux of course.

My Emacs configuration is used as an example to configure Emacs in the container.

Define the image via a Dockerfile

The Dockerfile (Dockerfile-web):

# Basic PHP container for Drupal PHP editing with Emacs.
#
# This Dockerfile is used from the Docker Compose file.
#
# Twitter: @maridonkers | Google+: +MariDonkers | GitHub: maridonkers.
#
# Docker image: https://hub.docker.com/_/drupal/
#
# BEWARE: firewall must allow docker interface for 3306 (otherwise connection errors).
#       : use http://127.0.0.1:8081 to access Drupal GUI if localhost doesn't work;

FROM drupal

RUN sed -i "s#\smain\s*\$# main contrib non-free#" /etc/apt/sources.list

RUN apt-get update && apt-get install -yq procps iproute2 sudo git-core zip curl gnupg
RUN apt-get install -yq emacs25 vim silversearcher-ag

ENV COMPOSER_ALLOW_SUPERUSER=1
RUN mkdir -p /opt/php
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/opt/php --filename=composer
RUN ln -s /opt/php/composer /usr/local/bin/composer

RUN sed -i "s#^\(www-data:.*:\)/usr/sbin/nologin#\1/bin/bash#" /etc/passwd
RUN echo "www-data ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers
# RUN usermod -u 1000 www-data
# RUN usermod -G staff www-data
RUN chown www-data /var/www
WORKDIR /var/www

ENV DISPLAY=:0

The Docker compose file

# Basic PHP container for Drupal PHP editing with Emacs.
#
# Twitter: @maridonkers | Google+: +MariDonkers | GitHub: maridonkers.
#
# Docker image: https://hub.docker.com/_/drupal/

version: '3'
services:
  web:
    # image: drupal
    build: 
      context: .
      dockerfile: Dockerfile-web
    environment:
       DISPLAY:
    network_mode: host
    # ports:
    #   - "8000:80"
    stdin_open: true
    tty: true
  db:
    image: mysql:5.7
    # volumes:
      # - ./db-backups:/var/mysql/backups:delegated
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_DATABASE: drupal1
      MYSQL_USER: drupal1
      MYSQL_PASSWORD: drupal1
    networks:
      - back
    ports:
      - "3306:3306"
  pma:
    image: phpmyadmin/phpmyadmin
    environment:
      PMA_HOST: db
      PMA_USER: root
      PMA_PASSWORD: root
      PHP_UPLOAD_MAX_FILESIZE: 1G
      PHP_MAX_INPUT_VARS: 1G
    networks:
      - back
    ports:
     - "8001:80"

networks:
  back:

Compose up

To build images and bring them up.

$ docker-compose up --build -d
Creating network "drupal1_default" with the default driver
Building web
Step 1/9 : FROM drupal
 ---> c362e86c8769
Step 2/9 : RUN sed -i "s#\smain\s*\$# main contrib non-free#" /etc/apt/sources.list
 ---> Using cache
 ---> 5624e4872798
Step 3/9 : RUN apt-get update && apt-get install -yq procps iproute2 sudo git-core zip curl gnupg
 ---> Using cache
 ---> 69d38cb8e0f2
Step 4/9 : RUN apt-get install -yq emacs25 vim silversearcher-ag
 ---> Using cache
 ---> 64b319596a11
Step 5/9 : RUN sed -i "s#^\(www-data:.*:\)/usr/sbin/nologin#\1/bin/bash#" /etc/passwd
 ---> Using cache
 ---> 24a125040132
Step 6/9 : RUN echo "www-data ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers
 ---> Using cache
 ---> 9ee3dddfffdb
Step 7/9 : RUN chown www-data /var/www
 ---> Using cache
 ---> 10062f436b3c
Step 8/9 : WORKDIR /var/www
 ---> Using cache
 ---> 73e32a4bb1f9
Step 9/9 : ENV DISPLAY=:0
 ---> Using cache
 ---> 0757563ba445
Successfully built 0757563ba445
Successfully tagged drupal1_web:latest
Creating drupal1_pma_1 ... done
Creating drupal1_web_1 ... done
Creating drupal1_db_1  ... done

Visit http://localhost:80 for the Drupal site. Visit http://localhost:8001 for the phpMyAdmin interface.

MySQL configuration

In the Drupal configuration screen use host 127.0.0.1 with port 3306 (plain localhost will not work).

Connect to development image

First enable access for X-Windows:

xhost +LOCAL:

Execute a bash shell in the container and set up Emacs.

$ docker exec -ti drupal1_web_1 /bin/bash

From the bash shell in the container:

# su - www-data

www-data$ git clone https://github.com/maridonkers/emacs-config.git /var/www/.emacs.d
Cloning into '/var/www/.emacs.d'...
remote: Enumerating objects: 114, done.
remote: Counting objects: 100% (114/114), done.
remote: Compressing objects: 100% (80/80), done.
remote: Total 545 (delta 68), reused 79 (delta 34), pack-reused 431
Receiving objects: 100% (545/545), 136.94 KiB | 0 bytes/s, done.
Resolving deltas: 100% (316/316), done.

www-data$ emacs --daemon
...
Loading /var/www/.emacs.d/loader.el (source)...done
Loaded /var/www/.emacs.d/loader.el
No desktop file.
Saving file /var/www/.emacs.d/init.el...
Wrote /var/www/.emacs.d/init.el
Wrote /var/www/.emacs.d/init.el
Starting Emacs daemon.

www-data$ emacsclient -nc html/index.php

If the emacsclient command doesn’t work the first time then restart the Emacs daemon by repeating the emacs --daemon and emacsclient -nc html/index.php commands.

Emacs running