Development on Apple macOS computers¶

Main questions:

How do I get the local development environment working on an Apple macOS computer?

Topics:

In this section, we will present the following topics:

A+ Docker containers and macOS
Troubleshooting

Material:

In this chapter, we do not provide additional material.

Requirements:

These instructions only apply to computers with the macOS operating system. Therefore, you should have an Apple computer.

Estimated working time:

From 10 min to 30 min.

A+ Docker containers and macOS¶

A+ works out-of-the-box on macOS, except for the MOOC-Grader, which is used for fetching and automatically grading assignments. Getting MOOC-Grader to work requires some extra configuration in the course's docker-compose.yml file. The next section introduces a socat solution that fixes the problems with the Unix sockets that behave differently on "Docker Desktop for Mac" than Linux/Ubuntu.

Configuration of the A+ Docker containers on macOS for local testing and development¶

Ensure that you have installed Docker Desktop for Mac and opened the application before trying to run the A+ Docker containers.

Open the docker-compose.yml file after you have cloned the course repository from Git.

Add the following under the service grader (indented inside the grader service settings):

environment:
  - DOCKER_HOST=tcp://socat:2375
links:
  - socat

Add a new service in docker-compose.yml after the existing services (plus and grader):

socat:
  image: alpine/socat
  command: TCP4-LISTEN:2375,fork,reuseaddr UNIX-CONNECT:/var/run/docker.sock
  volumes:
    - /var/run/docker.sock:/var/run/docker.sock
  expose:
    - "2375"

Your docker-compose.yml file should now look similar to the following example:

version: '3'

volumes:
  data:

services:
  grader:
    image: apluslms/run-mooc-grader:1.19
    volumes:
      - data:/data
      - /var/run/docker.sock:/var/run/docker.sock
      - /tmp/aplus:/tmp/aplus
      - .:/srv/courses/default:ro
    ports:
      - "8080:8080"
    environment:
      - DOCKER_HOST=tcp://socat:2375
    links:
      - socat
  plus:
    image: apluslms/run-aplus-front:1.19
    volumes:
      - data:/data
    ports:
      - "8000:8000"
    depends_on:
      - grader
  socat:
    image: alpine/socat
    command: TCP4-LISTEN:2375,fork,reuseaddr UNIX-CONNECT:/var/run/docker.sock
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    expose:
      - "2375"

When you open the A+ site in the web browser (address http://localhost:8000/) you should now be able to view and submit assignments and also receive the feedback in A+.

Note

If you have an Apple Silicon computer, be sure to use container image version 1.19 or higher for apluslms/run-aplus-front and apluslms/run-mooc-grader, since the older images do not feature support for the arm64 processor architecture of Apple Silicon computers. Native containers run faster than the x86_64 containers that are run via the Rosetta translation layer.

Troubleshooting¶

If you receive a PermissionError from the MOOC-Grader container after starting the A+ containers with docker-up.sh, you may need to change the owner of the Docker socket (Unix socket, a file in the filesystem) inside the MOOC-Grader container.

First, run docker-up.sh in a terminal. Then, open the grader command-line in another terminal and change the Docker socket owner:

docker exec -it aplus_grader_1 /bin/bash
chown grader /var/run/docker.sock

The MOOC-Grader Docker socket permissions are now fixed on macOS and you should be able to view and submit assignments and also receive the feedback in A+.