Docker & Kubernetes

Basic Commands

Command	Use	Example
docker build .	Create a docker image from the 'Dockerfile' inside project folder	-
docker run -p port:port image_id	Use the image_id generated from docker build . command to run the container	docker run -p 3000:80 c1ae0f4d8dd7
docker ps	List all running docker containers / processes (ps - processes)
docker stop container_name	Stop the docker container using the name of the container	docker stop laughing_taussig
docker ps -a	Lists all containers
docker run -it image_name	Run container in interactive mode (it - interactive). After running this command node will run inside this container no in our local machines	docker run -it node
docker ps --help	Lists all command related option	docker ps -a --help
docker run containerId	Runs docker in attached mode	docker start lucid_robinson
docker start containerId	Starts docker in detached mode	docker run -p 8000:80 72b446e12c
docker logs containerName	view logs	docker logs epic_ptolemy
docker logs -f containerName	View logs contineously in attached mode	docker logs -f epic_ptolemy
docker attach containerName	Attach a started container to view logs contineously in attached mode	docker attach epic_ptolemy
docker rm container1,container2	Removes the specified containers	docker rm laughing_taussig epic_blackwell amazing_mclean
docker images	To view all images	docker images
docker rmi imageId	Delete specific image	docker rmi 1ccdd95065ec
docker run -p port -d --rm containerId	removes container after being stopped	docker run -p 3000:80 -d --rm 1c7f4cb9788
docker image inspect imageId	inspected the docker image	docker image inspect 1c7f4cb9788b
docker cp localpath containerId:/path	Copying files into container	docker cp dummy/. mystifying_pike:/test
docker cp containerId:/path localpath	Copying files from container to local	docker cp mystifying_pike:/test/text.txt dummy
docker run -p 3000:80 -d --rm --name containerName imageId	Give a custome name to a container	docker run -p 3000:80 -d --rm --name goalsapp 2cc001395023
docker build -t name:tag .	Tagging a image	docker build -t goals:latest .
docker tag imageId:tag dockerhubId and docker push dockerhubId	Push your images to docker hub. First create a dockerhub account, create a repository, tag your existing repo with same a repo id of docker hub, then do login using cli and then push	docker tag nodeapp:latest shaggy356/node-hello-world and docker push shaggy356/node-hello-world
docker image prune -a	Deletes all the images	docker image prune -a
docker pull imageId (as per docker hub)	Pull published image	docker pull shaggy356/node-hello-world
docker volume ls	Check the docker volumes	docker volume ls
docker run -d -p 3000:80 --rm --name appName -v volumeName:path name:tag	This Docker command runs a container named feedback-app in detached mode (-d), mapping port 3000 on the host to port 80 inside the container. It uses the image feedback-node:volumes, mounts a named volume feedback to /app/feedback inside the container, and automatically removes the container when it stops (--rm).	docker run -d -p 3000:80 --rm --name feedback-app -v feedback:/app/feedback feedback-node:volumes

🖼️ What is a Docker Image?

• A blueprint for creating containers.
• Contains Node.js, your app code, and dependencies.
• Cannot run on its own.

📦 What is a Docker Container?

• A running instance of a Docker image.
• Can start, stop, or delete it anytime.
• Runs your Node.js app inside an isolated environment.

🖥️ Diagram: Docker Image vs Container

📦 Image (Blueprint)
├── App Code
├── Libraries
├── Dependencies
└── OS (optional)

🚀 Container (Running Instance)
├── Image + Read/Write Layer
├── Running Processes
├── Network & Storage
└── Unique Container ID

🔥 Key Differences

Feature	Image (📦)	Container (🚀)
What is it?	A template	A running app
State	Read-only	Read-Write
Runs?	❌ No	✅ Yes
Changes?	Fixed	Can change

---

🏗 Example: Node.js App in Docker

# Step 1: Pull a Node.js image
docker pull node

# Step 2: Create and run a container
docker run -it node bash

# Inside the container, check Node.js version
node -v

Running the external images

docker run node

This command will download and run the latest node images from Docker Hub

Catalogue

App	Location
Basic docker image creation	Basic
NodeJS app image creation	NodeJS App