Publish/Subscribe (or pub/sub for short) is a popular indirect communication system. Pub/sub systems disseminates events to multiple recipients (called subscribers) through an intermediary. Examples of successful pub/sub include Twitter and Bloomberg terminal-like financial systems. In this project, we will emulate a pub/sub system using Docker which is a computer program that performs operating-system-level virtualization, also known as "containerization".
You will need to install docker if you do not have it already.
$ sudo snap install docker
$ sudo snap services
$ sudo snap start docker
If you do not want to type sudo everytime you give a command in docker, please continue with the following commands.
$ whoami
$ sudo groupadd docker
$ sudo usermod -aG docker $USER
Now restart your OS. Start a terminal again.
$ docker --version #checking if docker is installed perfectly
$ docker run hello-world # download an official image "hello-world" from docker hub and run it in a container
(simple flask app and MyWayPoints django app)
First go the phase-01/Simple_Flask_App directory. Then run the below commands:
docker build -t simple-flask-app . # create a new image named "simple-flask-app" using the dockerfile in that directory
docker run -d -p 50:5000 --name flask-container simple-flask-app # running the image in a new container named "flask-container"
Now, go to the url 127.0.0.1:50 to see the output of the app from docker. Here 50:5000 is port mapping from container to host where 50 is the port of host.
First go the phase-01/MyWayPoints_v1 directory. Then run the below commands:
docker build -t simple-django-app . # create a new image named "simple-django-app" using the dockerfile in that directory
docker run -d -p 80:8000 --name django-container simple-django-app # running the image in a new container named "django-container"
Now, go to the url 127.0.0.1:80/map to see the output of the app from docker.
(Distributed Publisher/Subscriber System with a Central Server)
First go the phase_02 directory. Then run the below commands:
docker build -t pubsub-image:v1 #create new image for pubsub application
docker run -d -p 80:80 --name pubsub_central pubsub-image:v1 #running image in a new container
Now go to url localhost:80 to see the output of the app from docker.
Here's a link to see the output: https://www.youtube.com/watch?v=fg4W4bTAShM
There are also screenshots available in the repo under the Screenshots folder.
(Distributed Publisher/Subscriber System with distributed servers)
First go the phase_03 directory. Then run the below commands:
docker-compose up
If you want to stop the servers, then press Ctrl+C
Here's a link to see the output: https://www.youtube.com/watch?v=femzLKh3CBg
There are also screenshots available in the repo under the Screenshots folder.
