In this example, we’re going to start with an image that includes the nginx web application server and PHP. When it comes to Docker, getting started can be pretty straightforward. Creating a new Docker image from an existing container Let’s start by creating a new image from an existing container. Use a Dockerfile: In this case, you use a file of instructions - the Dockerfile - to specify the base image and the changes you want to make to it.Create a Docker image from an existing container: In this case, you start with an existing image, customize it with the changes you want, then build a new image from it.In this guide, we’re going to look at two methods for creating a new Docker image: (For further information on creating a Docker base image, including instructions on using tar to package a parent image, check out the Docker docs.) How do I create a Docker image? In that case, skip forward to the Using a Dockerfile section. Well, in most cases there’s a base image already available to do exactly that.īut maybe you want to spin up a bare-bones foundation for your new container…using Docker’s scratch image.
![docker desktop application docker desktop application](https://miro.medium.com/proxy/1*-a2_AsOLk5v4GjhdtLSGTw.png)
I hear you asking, “But what if I want to start from scratch?” Well, let’s define “from scratch.” Chances are, you mean that you want to start with a clean operating system and go from there. So in order to create an image, you are basically starting with a base image and defining the changes to it.
![docker desktop application docker desktop application](https://blogs.sap.com/wp-content/uploads/2021/08/Kubernetes.png)
In other words, if you start out with an image that’s just the operating system (say Windows) and then add an application (say Nginx), you’ll wind up with something like this:Īs you can see, the difference between IMAGE1 and IMAGE2 is just the application itself, and then IMAGE4 has the changes made on layers 3 and 4. The key to a Docker image is that it’s a layered file system.
![docker desktop application docker desktop application](https://projectriff.io/img/docker-vm-config-windows.png)
#Docker desktop application how to#
In this guide, you’ll learn how to create Docker images so you can deploy your own applications and make them available to other people. Whether you’re just getting started containerizing applications or you’re diving deeper into Kubernetes development, knowing how to create your first Docker images for applications is an essential skill.