Demo Image Creation Docker Commit Method

In this tutorial, you’ll learn how to build an HTTPD webserver image on top of a CentOS 7 base image using the Docker commit method. By the end, you’ll have a reusable image that includes your custom Apache configuration and index page.

1. Pull the CentOS 7 Base Image

Start by pulling the official CentOS 7 image from Docker Hub:

docker image pull centos:7

You should see output like:

7: Pulling from library/centos
75f829a71a1c: Pull complete
Digest: sha256:19a79828ca2505eae0ff38c2f39901f4826737295157cc5212b7a372cd2b
Status: Downloaded newer image for centos:7
docker.io/library/centos:7

Verify it’s available locally:

docker image ls

Example:

REPOSITORY   TAG   IMAGE ID       CREATED        SIZE
centos       7     7e6257c9f8d8   2 months ago   203MB

2. Create and Start a Container

Create a container named test from the CentOS 7 image:
```
docker container create --name test centos:7
```
Start it:
```
docker container start test
```

Attach an interactive shell:

docker container exec -it test /bin/bash

3. Install HTTPD and Customize the Web Page

Inside the container shell:

yum -y update
yum install -y httpd
echo "<h1>Hello from KodeKloud</h1>" > /var/www/html/index.html

This installs Apache HTTPD and replaces the default index page.

Tip

You can test the Apache service within the container before committing:

httpd -k start
curl http://localhost
httpd -k stop

4. Commit the Container to a New Image

Exit and stop the container:
```
exit
docker container stop test
```
Review container status:
```
docker container ls -l
```
Commit with metadata and a default CMD. Here’s an overview of common flags:

Flag	Description	Example
-a	Specify the author	`-a "Yogesh Raheja"`
-m	Add a commit message	`-m "Add HTTPD and custom index"`
-c	Set a Dockerfile instruction (e.g., CMD)	`-c 'CMD ["httpd","-D","FOREGROUND"]'`

Run docker commit:

docker container commit \
  -a "Yogesh Raheja" \
  -m "Add HTTPD and custom index" \
  -c 'CMD ["httpd", "-D", "FOREGROUND"]' \
  test webtest:v1

You’ll get a new image ID, for example:

sha256:9cd11553a2e7...

Verify the image list:

docker image ls

Expected:

REPOSITORY   TAG   IMAGE ID       CREATED         SIZE
webtest      v1    9cd11553a2e7   30 seconds ago  328MB
centos       7     7e6257c9f8d8   2 months ago    203MB

5. Test Your Custom Image

Launch a container from webtest:v1, mapping port 80:

docker container run -d --name webtesting -p 80:80 webtest:v1

Confirm it’s running:

docker container ls -l

Open http://<DockerHostIP> in your browser. You should see:

Hello from KodeKloud

This verifies that your HTTPD configuration and custom index page are baked into the image.

6. Tag and Push to Docker Hub

Tag the image for your repository (replace <your-dockerhub-username>):

docker image tag webtest:v1 <your-dockerhub-username>/codekloud-webtest:v1

Push the tagged image:

docker push <your-dockerhub-username>/codekloud-webtest:v1

Visit your Docker Hub repository to confirm the v1 tag is published.

Congratulations! You’ve successfully created and published a custom Docker image using the docker commit method.

References

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