Deploy Web application Using Docker Swarm

The project aims to deploy a web application using Docker Swarm, an efficient container orchestration tool that simplifies the management and scaling of containerized applications.

Requirements

1. Python 3.9
2. Node.js
3. React
4. Docker
5. AWS Account

Deploy process

Step 1. Create 3 ec2 instances called

• Swarm-manager
• Swarm-worker-1
• Swarm-worker-2

Step 2. Clone the repository to the ec2

git clone https://github.com/NirmalNaveen20/swarm-web-deployment

Step 3. Install docker with docker engine in all 3 nodes

Docker installation doumentaion

Check docker version

sudo docker --version

Step 4. Run docker build to create image

sudo docker build -t notes-app

Step 5. Add inbound rules to all 3 nodes

Custom TCP - 2377 - Anywhere IPV4 Custom TCP - 8000 - Anywhere IPV4

Step 6. Creating manager and worker nodes

Now open the "Swarm manager" node and run the command

sudo docker warm init

This will be creating empty swarm.

After initializing the swarm on the “swarm-manager” node, there will be one key generated to add other nodes into the swarm as a worker. Copy and run that key on the rest of the servers.

(Now, both machines are added to the swarm as a worker).

To check about all the nodes in the manager, run sudo docker node ls

Step 7. Push Docker image to the docker hub

Before push image to the docker hub, please login with your docker-hub credentials

docker login

Now tag the image using your docker-hub username and version

sudo docker tag notes-app <docker-hub-username>/django-notes-app:latest

Now push to the docker hub

sudo docker push <docker-hub-username>/django-notes-app:latest

Step 8. Create docker swarm service

Now Create a service in the docker manager node server to install the application through the docker image from the docker hub.

sudo docker service create --name django-notes-app --replicas 3 --publish 8000:8000 <docker-hub-username>/django-notes-app:latest

Now, run sudo docker service ls in manager mode you can see service is up and running

Now, this service will create a container in the Manager node and worker 01 and worker 02 node.

To check, run the command: sudo docker ps

Now, service will be running on all three nodes. To check this, just grab the Ip Address of any of the nodes followed by port 8000.

http://:8000 check on all 3 nodes(manager, worker 1,2 [ec2 instances])

Step 9. Scale up and Scale down Docker swarm service containers

In Docker Swarm, you can scale up or scale down the number of replicas (tasks) for a service using the docker service scale command. This command allows you to change the number of replicas, effectively increasing or decreasing the desired number of instances for a particular service.

Scale Up: To increase the number of replicas for a service:

docker service scale <service_name> = <replica_count>

Make Drain(Inactive) to manager node using following command.

docker node update --availability drain <node name>

Author

• @Nirmal Naveen