batch-42/dockerday2 at main · CloudDevOpsHub/batch-42 · GitHub

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 1  curl -fsSL https://get.docker.com -o install-docker.sh
    2  ls
    3  sh install-docker.sh
    4  docker --version
    5  docker ps
    6  docker ps -a
    7  docker images
    8  docker run hello-world
    9  docker ps
   10  docker ps -a
   11  docker images
   12  docker run -it ubuntu
   13  docker ps
   14  docker ps -a
   15  docker start 8aafca4a6f92
   16  docker ps
   17  docker exec -it 8aafca4a6f92 bin/bash
   18  docker ps
   19  docker images
   20  docker commit 8aafca4a6f92 anuragiswrongimage
   21  docker images
   22  docker pull nginx
   23  docker images
   24  docker run nginx
   25  docker ps
   26  docker ps -a
   27  docker run -p 80:80 nginx
   28  docker run --name docker-nginx -p 80:80 nginx
   29  docker ps -a
   30  docker run --name -d docker-nginx -p 80:80 nginx
   31  docker run --name docker-nginx -d -p 80:80 nginx
   32  docker run --name docker-nginx1 -d -p 80:80 nginx
   33  history


# 🐳 **Docker Installation & Basic Commands – Practice Guide**

> 📘 **Hands-on Docker practice on Linux**
> Learn how to install Docker, manage containers & images, and test using **Nginx**.

---

## 🔹 **1. Install Docker**

```bash
curl -fsSL https://get.docker.com -o install-docker.sh
📌 Explanation:
➡️ Downloads the official Docker installation script and saves it as install-docker.sh.

ls
📌 Explanation:
➡️ Verifies that install-docker.sh is downloaded.

sh install-docker.sh
📌 Explanation:
➡️ Installs Docker Engine on your Linux system.

🔹 2. Verify Docker Installation
docker --version
📌 Explanation:
➡️ Confirms Docker installation and displays the installed version.

🔹 3. Container Management Commands
docker ps
📌 Explanation:
➡️ Shows only running containers.

docker ps -a
📌 Explanation:
➡️ Shows all containers (running + stopped).

🔹 4. Image Management Commands
docker images
📌 Explanation:
➡️ Lists all locally available Docker images.

🔹 5. Run Test Container
docker run hello-world
📌 Explanation:
➡️ Runs a test container to verify Docker is working correctly.

🔹 6. Run Ubuntu Container (Interactive Mode)
docker run -it ubuntu
📌 Explanation:
➡️ Starts an Ubuntu container in interactive terminal mode.

🔹 7. Start Existing Container
docker start <container_id>
✅ Example:

docker start 8aafca4a6f92
📌 Explanation:
➡️ Starts a previously stopped container.

🔹 8. Access Container Terminal
docker exec -it <container_id> /bin/bash
✅ Example:

docker exec -it 8aafca4a6f92 /bin/bash
📌 Explanation:
➡️ Opens a bash terminal inside a running container.

🔹 9. Create Image from Container
docker commit <container_id> <new_image_name>
✅ Example:

docker commit 8aafca4a6f92 anuragiswrongimage
📌 Explanation:
➡️ Creates a new Docker image from the container state.

🔹 10. Pull Nginx Image
docker pull nginx
📌 Explanation:
➡️ Downloads the official Nginx image from Docker Hub.

🔹 11. Run Nginx Container
docker run nginx
📌 Explanation:
➡️ Runs Nginx container (not accessible externally yet).

🔹 12. Run Nginx with Port Mapping
docker run -p 80:80 nginx
📌 Explanation:
➡️ Maps container port 80 to host port 80
➡️ Access via browser: http://localhost

🔹 13. Run Nginx in Background with Name
docker run --name docker-nginx -d -p 80:80 nginx
📌 Explanation:

--name → Assigns container name

-d → Runs in background (detached mode)

-p 80:80 → Port mapping

❌ 14. Common Mistake
🚫 Wrong Command

docker run --name -d docker-nginx -p 80:80 nginx
✅ Correct Command

docker run --name docker-nginx -d -p 80:80 nginx
⚠️ Reason:
➡️ --name must be followed immediately by the container name.
➡️ Flag order matters!

🔹 15. Command History
history
📌 Explanation:
➡️ Displays previously executed commands (useful for revision & troubleshooting).

🎯 Practice Tip
http://localhost
✅ If you see the Nginx Welcome Page,
🎉 Docker networking is working perfectly! 🚀