"Dockerize Your Web Application: A Step-by-Step Guide to Creating a Dockerfile"
1- What is docker?
Docker is a platform that makes it easy to create, deploy, and run applications in a containerized environment. Containers are like virtual machines, but instead of simulating a whole computer, they provide a lightweight, isolated environment for running an application and its dependencies. Docker allows developers to package an application and all its dependencies into a single container, making it easy to move the application between development, testing, and production environments. This can save time and prevent issues caused by differences in the underlying infrastructure. Docker is widely used in software development and DevOps to streamline the application lifecycle and improve collaboration between teams.
2- What is dockerfile?
A Dockerfile is a script or recipe that contains instructions for building a Docker image. It specifies the base image to use, as well as any additional software that needs to be installed and any configuration that needs to be done.
The Dockerfile is used to automate the process of creating Docker images, which can be thought of as snapshots of an application and its dependencies. With Dockerfiles, you can define the exact environment that your application needs to run, which makes it easy to share and deploy your application on different machines or in different environments.
To use a Dockerfile, you would typically start by creating a new directory on your machine and creating a new file called "Dockerfile" in that directory. Then, you would add the necessary instructions to the Dockerfile and run the "docker build" command to build the image. Once the image is built, you can use the "docker run" command to create a container from the image and start your application.
-------TASK--------
Create a Dockerfile for a simple web application
1- First connect to the terminal with your own system or use an AWS EC2 instance. And install "docker " on the system
2-Give root permission to the User for "docker"
3- Git clone a repo to your system of web application or pull an image from the docker hub- In my case I git clone a repo from my mentor "Shubham londhe" Github.
4- Do ls command to see the list of git pulled repo- As you can see "Dockerfile" already exists you can use that docker file or create a new one for practice after removing the existing file.
5- This is the "docker file" to build a docker image.
6- Run the docker file to build the docker Image.
docker build . -t image_name
7- docker ps to view the docker image build.
8- Run the docker image to create a container, and run docker ps to see container
docker run -d -p port:port container_name:latest
docker ps
9- Go to your AWS instance, and go to security to edit the change.
10- Go to Edit bound and add a rule for port 8000 as custom tcp to Anywhere. And Save the rule.
11- You will see an update for successful change.
12- Again go to the instance and scroll down go to details and copy the IP address.
13- Open a new window and paste the IP address along with port 8000
eg: IP address:8000. You will able to see the web application running. I am really sorry I forgot to screenshot the web page. But worry not the web page will run. and the page will look like the image given below.
14- push the docker image to the docker hub account:
a- docker login and provide a username and password
b- docker tag image_name username/image-name:latest and do docker ps to view the tag
c- docker push username/image_name:latest
And hence that's the whole process. Now let's get with some commands:
Try these commands:
1- docker run: This command is used to create and start a new Docker container. You can specify the image to use, as well as any additional settings like ports, volumes, environment variables, etc.
2- docker inspect: This command is used to get detailed information about a Docker container, image, network, or volume. It returns a JSON object containing various details about the specified resource.
eg: docker inspect image_name
3- docker port: This command is used to show the public-facing port of a container. You can specify the container ID or name, and Docker will display the mapping between the container's internal port and the host machine's port.
eg: docker port container_ID
4- docker stats: This command is used to display live performance metrics for one or more running containers. It shows CPU usage, memory usage, network I/O, and other statistics in real time.
eg: docker stats container_ID
5- docker top: This command is used to show the running processes inside a container. You can specify the container ID or name, and Docker will display the list of processes along with their resource usage.
eg: docker top container ID
6- docker save: This command is used to save a Docker image to a file. The image can be compressed and exported as a tarball, which can then be shared or moved to another machine.
eg: docker save image_ID -o image_name.tar "-o is used to bind the docker image with the tar file"
7- docker load: This command is used to load a Docker image from a file. The image can be a tarball created with docker save, and it will be imported into the local Docker registry. and as you can see the load command loads an image ID which can be run to build a "docker image"
eg: docker load < tarfile
Thank you for taking the time to read my blog on creating a Dockerfile for a simple web application. I hope the step-by-step guide has been helpful in streamlining your deployment process and that you now feel more confident in using Docker to manage your web applications. Don't hesitate to reach out if you have any questions or feedback. Happy Dockerizing!
LinkedIn - https://www.linkedin.com/in/amit-kumar-3576191b4/