Docker Installation and Management

 # Step 1: Uninstall older versions of Docker if they exist

sudo dnf remove docker \

                docker-client \

                docker-client-latest \

                docker-common \

                docker-latest \

                docker-latest-logrotate \

                docker-logrotate \

                docker-engine

# Step 2: Add Docker's official repository

sudo dnf config-manager --add-repo https://download.docker.com/linux/rhel/docker-ce.repo

# Step 3: Install Docker Engine

sudo dnf install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# Step 4: Start and enable Docker service

sudo systemctl start docker

sudo systemctl enable docker

# Step 5: Verify that Docker is installed and running

sudo systemctl status docker

# Check Docker version

docker --version

# Step 6: Run a test container to confirm installation

sudo docker run hello-world

# Step 7: (Optional) Allow non-root user to run Docker commands

sudo usermod -aG docker $USER

newgrp docker

# Step 8: Enable Docker to start on boot

sudo systemctl enable docker.service

sudo systemctl enable containerd.service

Project Deployment
This is project is docker based deployment consist of following services.
1) MongoDB
2) Mongo Express (GUI)

It is admin interface to connect, manage MongoDB.
3) Express JS (Api's)

1) Download Mongo Image.
Download mongo image using docker hub command. This command will download image and run it as a container.

Command

--docker run -d \

  -p 27017:27017 \

  --name mongo \

  --network mongo-network \

  -e MONGO_INITDB_ROOT_USERNAME=admin \

  -e MONGO_INITDB_ROOT_PASSWORD=qwerty \

  mongo

Note: Port binding is very important. mongoDB is running inside container and you nodejs app is also running inside the container using same network than set url "mongo" to node app server file .

const MONGO_URL = "mongodb://admin:qwerty@mongo:27017";

When the node js app is host directly using pm2/or in ither network container than set url to "localhost" in node js app server file.

const MONGO_URL = "mongodb://admin:qwerty@localhost:27017";

This port   -p 27017:27017 \ binding is very import if you node app is host in other network container/ host directly via pm2
Note: Not required in within same docker network.

2) Download Mongo Express Images.

Download mongo-express image using docker hub command. This command will download image and run it as a container.

docker run -d \

  --name mongo-express \

  --network mongo-network \

  -p 8081:8081 \

  -e ME_CONFIG_MONGODB_ADMINUSERNAME=admin \

  -e ME_CONFIG_MONGODB_ADMINPASSWORD=qwerty \

  -e ME_CONFIG_MONGODB_URL="mongodb://admin:qwerty@mongo:27017/admin" \

  mongo-express

Note: The port binding with Host is very important while running mongo-express container.
Other wise you can access with your public host your mongo DB. 

Now access your mongo-express using the url
http://<your-server-ip>:8081

Host your Nodejs App

Step 1

Open port 3003

firewall-cmd --permanent --add-port 3003/tcp

firewall-cmd --reload

Step 2 Upload project on server

We have an example nodejs app. we will clone it from the git repository.

git clone https://github.com/shradha-khapra/docker-testapp.git

Step 3 Edit server.js file

Change or update the port to 3003

Step 4 Run the Application using pm2 service manager

pm2 start npm --name "docker_test_backend_app" -- run start