A backend server for a centralized elevator system.

This is a packaged program and requires docker and docker-compose to be installed along with access to docker hub to pull images.

Run the following commands in the directory with Dockerfile to build the server. It may take 3-5 mins on first run. Depending on your operating system you may or may not need to use sudo.

sudo docker compose build

Run the following command to start the server.

sudo docker compose up

Known issue: The first time running sudo docker compose up after build might cause an error in the db connection. Try shutting it down with Ctrl+c, sudo docker compose down and then run sudo docker compose up again. This should work for the time being.

After you are done run the following command to uninstall the built containers

docker compose down

Also check for any unwanted base images and remove them

sudo docker images

sudo docker rmi -f <image-id-here>

In addition to the requested API's, I have added 2 new API's for added functionality. I may have also merged some requested API with similar objectives, while maintaining its intended purpose. Please note, not passing the parameters may result in errors although most cases have validations. Some parameters have hard limits and can be modifed in the constants.py file.

The program assumes there are buildings with a set amount of floors and elevators.

http://0.0.0.0:8080/elevator/building/

• POST Creates a building and it's elevators in the database. It requires the following parameters:

  • name: Name of the building. Duplicates are allowed
  • floors: Number of max floors in the building. Hard limit: 60.
  • elevators: Number of elevators to be created. Hard limit: 10.

• GET Fetch info about a building and it's elevators.

  • id: Id of the building.

Various elevator related operations make use of this api.

http://0.0.0.0:8080/elevator/elevator/

• POST Adds destination to an elevator. This API assumes the client has pushed the button on a floor, and has a destination floor in mind. When executed, the program will select an appropriate elevator, and that will have assumed to have arrived where the client called, with the clients destination added to its list of destinations. It will need to move using the move api discussed later.

  • building_id: Id of the building at which the client is at.
  • called_at: The floor at which the client is at.
  • dest: The destination floor of the client.

• GET Fetches the movement status (going up/down or stopped)of an elevator and the next floor it will arrive at.

  • id: The id of the elevator.

• PUT Updates an elevator's operational status (maintainence/malfunction) and its door (open/closed).

  • id: Id of the elevator
  • operational: (optional) 'yes' or 'no'
  • door: (optional) 'open' or 'close'.

Functionalities for elevator's movement

http://0.0.0.0:8080/elevator/move/

• POST Moves all the elevators by 1 step in a building.

  • building_id: Id of the building to simulate elevator movement

Probably needed a better word, but here logs mean the list of destinations of an elevator.

http://0.0.0.0:8080/elevator/logs/

• GET Fetches all requests for a give elevator.

  • id: Id of the elevator.

For a closer view of what's happening, open a new window while the server is running.

sudo docker ps

The above command will show two containers running, one of the main django app and the other of postgres. In order to access bash use the following command:

sudo docker exec -it <name-or-id-of-image> bash

In the postgres container use the following to access the database with password postgres:

psql -h db -U postgres