Docker manifest tool

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Looks like a Docker image has two manifests. One is local, that is saved as a part of docker savefor example, and a different one that is generated when the image is being pushed to Docker registry.

So, my question is there a way to find this registry manifest file? Is it stored somewhere locally? Maybe inside the Docker. Today's Docker engine uses the manifest as a guide to determine what other content layer blobs to download during a docker run where the image is not local or docker pull.

However, it does not store the manifest as JSON in a local cache that I'm aware of, leaving you without an easy spot to go get the actual registry's manifest. Learn more. Location of the local copy of Docker's registry manifest-file Ask Question.

Asked 2 years, 7 months ago. Active 2 years, 7 months ago. Viewed times. JBaruch JBaruch Automation of some sort. Why does it matter? Since you mentioned qcow2 I assume you are using Docker for mac. See if these pointers are of any help? Seems like this is generated at runtime github. Active Oldest Votes. Two things that may be of interest: We are in the process of adding a new docker manifest command for direct interaction with the manifest object that may be of interest to what you are trying to do.

This is mostly to support the "manifest list" v2. Phil E Phil E 1, 8 8 silver badges 15 15 bronze badges.Legacy desktop solution. We recommend updating to the newer applications, if possible. Docker Toolbox provides a way to use Docker on Windows systems that do not meet minimal system requirements for the Docker Desktop for Windows app. Instead, you must use the Docker Machine command, docker-machineto create and attach to a small Linux VM on your machine.

Tip : One of the advantages of the newer Docker Desktop for Windows solution is that it uses native virtualization and does not require VirtualBox to run Docker. To run Docker, your machine must have a bit operating system running Windows 7 or higher.

Additionally, you must make sure that virtualization is enabled on your machine. To verify your machine meets these requirements, do the following:. If you have a newer system, specifically 64bit Windows 10 Pro, with Enterprise and Education Anniversary update, Build or laterconsider using Docker Desktop for Windows instead.

It runs natively on the Windows, so there is no need for a pre-configured Docker QuickStart shell. It also uses Hyper-V for virtualization, so the instructions below for checking virtualization will be out of date for newer Windows systems. Full install prerequisites are provided in the Docker Desktop for Windows topic in What to know before you install. Make sure your Windows system supports Hardware Virtualization Technology and that virtualization is enabled.

Run Speccyand look at the CPU information. Under CPU you should see the following:. How you do this verification depends on your Windows version.

Building multi-arch docker images

For details, see the Windows article How to determine whether a computer is running a bit version or bit version of the Windows operating system. The installation adds the following software to your machine:. If you have a previous version of VirtualBox installed, do not reinstall it with the Docker Toolbox installer. When prompted, uncheck it. Note : Docker no longer maintains the download.

To download the latest version of Docker Toolbox, go to Toolbox Releases and download the latest. If Windows security dialog prompts you to allow the program to make a change, choose Yes. The system displays the Setup - Docker Toolbox for Windows wizard.

Accept all the installer defaults. The installer takes a few minutes to install all the components:. When notified by Windows Security the installer will make changes, make sure you allow the installer to make the necessary changes. In this step, you start Docker Toolbox and run a simple Docker command.

docker manifest tool

If the system displays a User Account Control prompt to allow VirtualBox to make changes to your computer. Choose Yes.

docker manifest tool

The terminal does several things to set up Docker Toolbox for you. The terminal runs a special bash environment instead of the standard Windows command prompt. The bash environment is required by Docker. You type commands into the command line which is the area after the prompt.In this post, we'll discuss Image Manifests, Manifest Lists, and their role in enabling multi-architecture Docker registries.

Then we'll walk through an example of setting up a multi-architecture Docker registry on a MacchiatoBin. Although we are using the MacchiatoBin in this blog, the instructions presented below will work on just about any AArch64 HW available on the market.

An Image Manifest is a file that contains information about the composition of a particular image. An example Image Manifest is shown below. The key portion of this file is the section labeled layers.

Subscribe to RSS

It lists all the layers that make up the image. The first layer is the base image, and the subsequent layers are the additional layers needed to compose the final image. This file is automatically created in the registry when an image is pushed into it.

A Manifest List is a file that contains a list of Image Manifests. Below is the Manifest List for the Docker Hub image ubuntu The key portion of this file is the section labeled manifests. This section lists six Image Manifests. The main difference between the listed Image Manifests is the architecture. On closer inspection, we can see that two of these Image Manifests are for Arm Ubuntu images. The Manifest List is how Docker Hub supports different architectures with the single image name and tag of ubuntu If there is, the registry will serve that version of the image to the client.

Let's walk through setting up a registry on the MacchiatoBin, then pull images from the registry from both the MacchiatoBin and an x86 machine. This will verify that the registry can serve multi-architecture images. Install the latest stable version of Docker. This can be done by running the following command on both the MacchiatoBin and on the x86 machine.

Notice that both the client and server have their experimental flags set to false.In this blog post I will describe how to create a Docker image that works on different hardware architectures and operating systems. I will create a Docker image based on a service written in Go and package it for use in both Linux and Windows on 64 bit Intel based hardware.

This blog post is part of the blog series - Trying out new features in Docker. A drawback with this multi-platform support is that one Docker image has to be built for each specific target platform, i.

So, if you want to be able to run your Docker container on both Linux and Windows using Intel bit hardware you must create two Docker images, one for Linux and one for Windows. You also have to create each Docker image using a Docker engine running on the specific target platform. When using the Docker images, you also have to specify what version you want to use, e. This makes it inconvenient to use together with tools like Docker Compose or a container orchestrator, e. Kubernetes or Docker in Swarm mode, since the configuration files Kubernetes yml files or docker-compose.

Work is, however, ongoing to support building multi-platform Docker images that are composed by platform specific Docker images. A new Docker tool, docker manifestis under development. For the time being, a standalone manifest tool maintained by Phil Estes from IBM can be used to create multi-platform Docker images.

For more details, see the following blog post from IBM: Create and use multi-architecture docker images. In SeptemberDocker announced that their official Docker images were updated to make them multi-platform aware, see the blog post Docker official images are now multi-platform.

I have developed a simple service, written in Go, that creates some random quotes about successful programming languages. See go-quotes. Go supports cross compilation, so I can create the executable files on the same developer machine. So, for the scope of this blog post, I will use Windows instead of macOS as my development environment.

Exploring Docker Manifests

Below follow instructions for how to build the platform specific Docker images and how to assemble a composed multi-platform Docker image.

Note : Pay special attention to the value of the fields hardwareArchitecture and operatingSystem in the response amd64 and windows in the response above. They will be used later on when we want to verify that we are communicating with a container on the expected platform. Look for the field OSTypeit should say windows. The Dockerfile for building the Windows Docker image, Dockerfile-windows-amd64looks like:. Note 2: You might need to login to DockerHub first, using docker login. You can use ipconfig to get the IP address.

Expect a similar response as from the curl command above. Verify that operatingSystem field has the value windows! The Dockerfile for building the Linux Docker image, Dockerfile-linux-amd64looks like:. Verify that operatingSystem field now has the value linux!

We will us the standalone tool manifest-tool.As part of my recent project to build an ARM based Kubernetes cluster more on that in a different post I have run into quite a few cross platform compatibility issues trying to get containers working in my cluster.

After a little bit of digging, I found that support was added in version 2. To add to this, I just recently discovered that in newer versions of Docker, there is a manifest sub-command that you can enable as an experimental feature to allow you to interact with the image manifests. The manifest command is great for exploring Docker images without having to pull and run and test them locally or fighting with curl to get this information about an image from a Docker registry.

After adding the experimental configuration to the client you should be able to access the docker manifest commands.

This will spit out a bunch of information about the Docker image, including schema, platforms, digests, etc. As you can see above image traefik supports arm and arm64 architectures. This is a really handy way for determining if an image works across different platforms without having to pull an image and trying to run a command against it to see if it works. This tool is more or less superseded by the built-in Docker manifest command but still works basically the same way, allowing users to inspect, annotate, and push manifests.

The manifest-tool has a few additional features and supports several registries other than Dockerhub, and even has a utility script to see if a given registry supports the Docker v2 API and 2. It is definitely still a good tool to look at if you are interested in publishing multi platform Docker images. One you have the manifest-tool set up you can start usuing it, similar to the manifest inspect command.

Likewise, you can annotate and push image manifests using the manifest-tool. Below is an example command for pushing multiple image architectures.

Super simple but useful for quickly getting platform information. You will still need to figure out how to build the image for each architecture first before pushing, but having the ability to use one image for all architectures is a really nice feature.

There is work going on in the Docker and Kubernetes communities to start leveraging the features of the 2. This will be a great boon for helping to bring ARM adoption to the forefront and will help make the container experience on ARM much better going forward. You can also find him on Twitter and Facebook. Python virtualenv Notes. Building k8s Manifests with Helm Templates.If you publish this image to a Docker registry for others to pull, this image might be okay for many scenarios.

However, in practice it's more common to be specific about what base image you use, what binaries you download, and which tool versions you install.

Using a specific tag for a base image is commonplace and makes it easy to remember that building or rebuilding images always has the same basis.

docker manifest tool

For more information, see Known issues for containers. The following example downloads the latest release of Build Tools. If you want to use an earlier version of Build Tools that you can install into a container later, you must first create and maintain a layout. To collect logs when an install error occurs, create a batch script that's named "Install. Visual Studio version No error is displayed.

See Known issues for containers for more information. For a list of workloads and components, see the Visual Studio Build Tools component directory.

This example downloads specific tools and validates that the hashes match. It also downloads the latest Visual Studio and. NET log collection utility so that if an install failure does occur, you can copy the logs to your host machine to analyze the failure.

Sometimes, things can go wrong. If your Visual Studio installation fails, see Troubleshoot Visual Studio installation and upgrade issues for step-by-step guidance. We also offer an installation chat English only support option for installation-related issues. You may also leave feedback directly on GitHub. Skip to main content. Exit focus mode. Tags can be changed, though that is unlikely for most images. COPY Install. For more control, specify the location of an internal layout.

AzureBuildTools workload, excluding workloads and components with known issues. This entry point starts the developer command prompt and launches the PowerShell shell. Sending build context to Docker daemon Is this page helpful? Yes No. Any additional feedback?This is amazing, thanks for sharing it! A very useful feature that I always missed but never actually tough about. I've had a hard time understanding the slices on the beginning will be very useful for troubleshooting bad images also while optimizing image sizes.

Can probably help to understand problems like the one bug where the image size got almost a 2x increase after a CHOWN, because the slice is added again with different owner I think ; would be so much easier to see with this. We added a lib to a java image and the size went up by about 4x the library size, I spent a few hours trying to track it down to no avail. Hopefully this will help pin down the issue. Might save someone else a headache in the future. Same here.

I'm relatively new to Docker. I've taken a public jessie image, and tweaked and committed locally. I can see that layers exist when I pull images, but just what they are has been a mystery. Project idea: a Google for docker images.

Search for files by hash within all public docker images.

docker manifest tool

Find images that contain a certain piece of code. Reverse engineering Dockerfiles for those that were built without. The latter can be easily done in a few hours by inspecting the image layer metadata. Every layer understands the command it was run in the Dockerfile to create itself. From there you can reverse-engineer a Dockerfile. The only information most tools will give you might just be the diff itself.

Can it be modified after creation by a malicious party? New project idea Crawl a large set of popular docker images lacking Dockerfiles and attempt to recreate the dockerfile with this technique.

A GitHub for Docker images might be the better analogy. Docker the company could, I imagine, add deep search and browsing as enhancements to their existing Docker Hub. Can someone well versed in Docker explain in their own words what this does and why it is useful? Thanks in advance! I'm definitely not a docker poweruser IMTDb on Nov 25, A docker image is built in layers that stack on top of each other. Think of each layer as a commit in a git repository.

A bit like a git log for a docker image. If OP looks up some Dockerfiles on docker hub, this will make more sense.