Shulou(Shulou.com)06/01 Report--

This article mainly introduces "the import and export method of Docker image and container". In the daily operation, I believe that many people have doubts about the import and export method of Docker image and container. The editor has consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "import and export method of Docker image and container". Next, please follow the editor to study!

I. Preface

With the development of container technology, many application systems will choose to deploy using docker containers, but sometimes there are problems when using docker containers for deployment. For example, our applications need to rely on images from other third parties. If the server cannot be deployed when the internal network is unable to connect to the external network, then it cannot be deployed. In view of this situation, docker officially supports the import and export of docker images and containers. We can compile the image on a networked machine, then export the image or container, and finally upload the exported image or container to the private network server, and then import the image or container.

The import and export of images and containers mainly involves the following commands: save, load, export, and import.

During the demonstration, we generate an image or container locally, then export the image or container, and finally upload it to the Ali cloud server to demonstrate the import feature.

We use VS 2019 to create an ASP.NET Core MVC project and add the Dockerfile file:

# use the runtime mirror FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim# to set up the working directory WORKDIR / app# to copy all the contents of the directory to the current directory COPY. . # expose port 80 EXPOSE 8 run image entry command and executable file name ENTRYPOINT ["dotnet", "DockerDemo.dll"]

Then publish the project. Let's look at the existing docker images

As you can see: there are only two images of. Net core. We generate an image:

Docker build-t dockerdemo.

As shown in the following figure:

View the generated image

Then we run the container based on the generated image, first looking at the existing container:

You can see that there are no containers at this time. We run the container:

You can see that the container has run successfully.

2. Import and export of docker images 1. Export of docker images

The commands involved:

Docker save [options] images [images...]

We use the image above to demonstrate the export of the image:

Docker save-o dockerdemo.tar dockerdemo

As shown in the following figure:

Here, the path of the exported file is specified when exporting. If you do not specify the path, the default is the current folder.

Or you can export using the following command:

Docker save > dockerdemo.tar dockerdemo

Where-o and > indicate the output to the file, dockerdemo.tar is the exported target file, and dockerdemo is the source mirror name.

Let's check to see if the exported file is available locally:

You can see that you already have the file you just exported under the directory.

2. Import of docker image

First, we use XFtp to upload the image file exported above to the Ali cloud server.

Then go to the directory where the file is located

Let's check which images are on the Ali CVM:

As can be seen from the image above: there are no images on the Ali CVM.

The import command load involved

Docker load [options]

Next, let's import the image we just uploaded.

Docker load-I dockerdemo.tar

As shown in the following figure:

Or you can use the following command

Docker load < dockerdemo.tar

Where-I (I is imput) and

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.