I was reading the docs regarding docker buildx build to build to multiple architectures and I got puzzled with the --push option, it says that it pushes to the registry directly but how does it know or how can I specify where I want it to push the built images?
For more context, my plan is to push the images to my Gitlab private container registry from my Gitlab CI/CD pipeline
First login to your private registry, with the command docker login myregistry.com. After that specify your registry in the tag name of your image docker buildx build --push -t myregistry/appname:version . and it should push your image after build.
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This question already has answers here:
How to copy multi-arch docker images to a different container registry?
(3 answers)
Closed 2 months ago.
I'm trying to pull a Docker image from Dockerhub and copy it into my own Dockerhub registry. I want to do this for all os/architectures available under the tag I am copying. For example, node:latest has the following architectures:
linux/amd64
linux/arm/v7
linux/arm64/v8
If I run the following:
docker pull node:latest
docker tag node:latest myregistry/node:latest
docker push myregistry/node:latest
I only end up with linux/amd64 in my registry, because my laptop is Intel and only pulls/pushes the Intel architecture. I want to be able to pull/push the arm architectures as well, so M1 users can pull from my registry.
How can I do this? The images are already built, so I don't want to have to rebuild them, and I don't have an M1. I just want to "copy" the image that has already been built into my registry.
This seems to have done the trick:
docker pull node:latest
docker manifest inspect # <- note the digests of the architectures you want to include
# Create a tag for any digests you are interested in
docker tag node:latest#sha256:867c09f220095929f3ab4113e7530a6e38833f2eb4317cb8998307528026621f myregistry/node:latest-amd64
docker tag node:latest#sha256:55298bd901ba7d9b914842c0cbb1087571b50121791846a17b78fa02f904962b myregistry/node:latest-arm64
# Push to your registry
docker push myregistry/node:latest-arm64
docker push myregistry/node:latest-amd64
# Create and push the manifest
docker manifest create myregistry/node:latest --amend myregistry/node:latest-arm64 --amend myregistry/node:latest-amd64
docker manifest push myregistry/node:latest
Dockerhub will list both architectures under the "latest" tag:
I am trying to build, sign, and push a multi-arch container image using a Harbor registry with Notary. Following the steps in https://www.cncf.io/blog/2021/07/28/enforcing-image-trust-on-docker-containers-using-notary/ I was able to get the simple example working with DOCKER_CONTENT_TRUST_SERVER pointing to the URL of my notary server.
However, when I try to build and push a multi-arch image, I do not get prompted about the trust metadata and it seems to completely skip the signing step. The command I'm running to build and push the multi-arch image is:
docker buildx build --file Dockerfile --push --platform linux/arm64,linux/amd64 --tag myharborregistry.com/myimage:latest .
Is there some extra step required to enable Docker Content Trust with buildx? Perhaps there is a flag that I am missing or some additional configuration needed for the builder?
Usually according to docs In order to build a docker Image I need to follow these steps:
Create a Dockerfile for my application.
Run docker build . Dockerfile where the . is the context of my application
The using docker run run my image into a container.
Commit my image into a container
Then using docker push push the image into a container.
Though sometimes just launching the image into a container seems like a waste of time because I can tag my images using the parameter -t into the docker build command. So there's no need to commit a container as an image.
So is neseserily to commit a running container as an image?
You don't need to run and commit. docker commit allows you to create a new image from changes made on existing container.
You do need to build and tag your image in a way that will enable you to push it.
docker build -t [registry (defaults to docker hub)]/[your repository]:[image tag] [docker file context folder]
for example:
docker build -t my-repository/some-image:image-tag .
And then:
docker push my-repository/some-image:image-tag
This will build an image from a docker file found in the current folder (where you run the docker build command). The repository in this case is my-repository, the image name is some-image and it's tag is image-tag.
Also please note that you'll have to perform docker login with your credentials to docker hub before you are able to actually push the image.
You can also tag an existing image without rebuilding it. This is useful if you want to push an existing image to a different registry or if you want to create a different image tag. for example:
docker tag my-repository/some-image:image-tag localhost:5000/my-repository/some-image:image-tag
This will add a new tag to the image from the previous example. Note the registry part added (localhost:5000). If you call docker push on that tag (docker push localhost:5000/my-repository/some-image:image-tag) the image will be pushed to a registry found on localhost:5000 (of course you need the registry up and running before trying to push).
There's no need to do so. In order to prove that you can just tag the image and push it into the registry here's an example:
I made the following Dockerfile:
FROM alpine
RUN echo "Hello" > /usr/share/hello.txt
ENTRYPOINT cat /usr/share/hello.txt
Nothing special just generates a txt file and shows its content.
Then I can build my image using tags:
docker build . -t ddesyllas/dummy:201201241200 -t ddesyllas/dummy:201201241200
And then just push them to the registry:
$ docker push ddesyllas/dummy
The push refers to repository [docker.io/ddesyllas/dummy]
1aa99de3dbec: Pushed
6bc83681f1ba: Mounted from library/alpine
201908241504: digest: sha256:93e8407b1d52620aeadd769486ef1402b9e310018cae0972760f8c1a03377c94 size: 735
1aa99de3dbec: Layer already exists
6bc83681f1ba: Layer already exists
latest: digest: sha256:93e8407b1d52620aeadd769486ef1402b9e310018cae0972760f8c1a03377c94 size: 735
And as you can see from the output you can just build the tags and push it directly, good for your ci/cd pipeline. Though, generally speaking, you may need to launch the application into a container in order to do acceptance and other type of tests (eg. end-to-end tests).
I want to use experimental docker buildx feature with my Jenkins pipeline docker.build.
AFAIK docker.build allows only build arguments provide. But want I need is provide build as argument itself provide to buildx
You can set alias for docker buildx by running this command docker buildx install.
This will use buildx builder whenever you call docker build.
Source
However, Jenkins' docker plugin doesn't support it at the time of writing and there is an open issue for that.
Alternatively, you can build images without plugin:
steps {
script {
sh """
docker build buildx ...
"""
}
}
I'm trying to push a docker image to an Azure container repository and even after successfully "logging in" the push command tries to push it to docker.io and then fails.
Note: I am using Windows 10 Pro and have set up docker to to use the minikube docker dameon
How do I tell docker push to use my Azure container repo?
See the output:
You must tag your image with the Docker Registry URL and then push like this:
docker tag design-service dockerregistry.azurecr.io/design-service
docker push dockerregistry.azurecr.io/design-service
Note: The correct term is registry and not repository. A Docker registry holds repositories of tagged images.