how to buid image using base image on local repo

[ishii1648]

I want to build image for another cpu architecture (build image for arm64 on x86 ).
When base image is hosted on dokcer.io, I success to build image.
But when base image is only hosted on local repository, I fail to build image.

Can I build image using base image on local repository?
If so, could you tell me how to build?

base image(ubuntu:18.04) is hosted on dokcer.io -> success

$ cat Dockerfile
FROM ubuntu:18.04
RUN apt-get update && apt-get install -y curl
WORKDIR /src
COPY . .
$ docker buildx build --platform linux/arm/v7 -t test-buildx --load . 
[+] Building 117.9s (10/10) FINISHED                                                                                                
 => [internal] load build definition from Dockerfile                                                                           0.1s
 => => transferring dockerfile: 123B                                                                                           0.0s
 => [internal] load .dockerignore                                                                                              0.0s
 => => transferring context: 2B                                                                                                0.0s
 => [internal] load metadata for docker.io/library/ubuntu:18.04                                                                3.3s
 => CACHED [1/4] FROM docker.io/library/ubuntu:18.04@sha256:3235326357dfb65f1781dbc4df3b834546d8bf914e82cce58e6e6b676e23ce8f   0.0s
 => => resolve docker.io/library/ubuntu:18.04@sha256:3235326357dfb65f1781dbc4df3b834546d8bf914e82cce58e6e6b676e23ce8f          0.0s
 => [internal] load build context                                                                                              0.0s
 => => transferring context: 123B                                                                                              0.0s
 => [2/4] RUN apt-get update && apt-get install -y curl                                                                      106.1s
 => [3/4] WORKDIR /src                                                                                                         0.1s
 => [4/4] COPY . .                                                                                                             0.0s
 => exporting to oci image format                                                                                              5.8s 
 => => exporting layers                                                                                                        3.0s 
 => => exporting manifest sha256:5b17b05614a3bc56d041b2b9c20287809a4d991c7eb5aea5edd967fa6d606d44                              0.0s 
 => => exporting config sha256:43053f0e59e955c21680843e3f75da89ef2729901a6e4b0d6ddd8b2525543c08                                0.0s 
 => => sending tarball                                                                                                         2.7s
 => importing to docker 
$ docker images | grep test-build
test-buildx                   latest              43053f0e59e9        About a minute ago   82.1MB

base image(test-buildx) is only hosted on local repository -> fail

$ cat Dockerfile
FROM test-buildx:latest
RUN apt-get update && apt-get install -y curl
WORKDIR /src
COPY . .
$ docker buildx build --platform linux/arm/v7 -t test-buildx2 --load .                                     
[+] Building 6.7s (5/8)                                                                                                             
 => [internal] load build definition from Dockerfile                                                                           0.0s
 => => transferring dockerfile: 129B                                                                                           0.0s
 => [internal] load .dockerignore                                                                                              0.0s
 => => transferring context: 2B                                                                                                0.0s
 => ERROR [internal] load metadata for docker.io/library/test-buildx:latest                                                    3.4s
 => ERROR [1/4] FROM docker.io/library/test-buildx:latest                                                                      3.3s
 => => resolve docker.io/library/test-buildx:latest                                                                            3.3s
 => [internal] load build context                                                                                              0.0s
 => => transferring context: 129B                                                                                              0.0s
------
 > [internal] load metadata for docker.io/library/test-buildx:latest:
------
------
 > [1/4] FROM docker.io/library/test-buildx:latest:
------
failed to solve: rpc error: code = Unknown desc = failed to load cache key: pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed

[tonistiigi]

I don't know what you mean by local repo. For registry on the localhost you need to put the builder container to host network with --driver-opt. For accessing images in docker images this is only possible with docker driver and not with container driver.

[manofthelionarmy]

I don't know what you mean by local repo. For registry on the localhost you need to put the builder container to host network with --driver-opt. For accessing images in docker images this is only possible with docker driver and not with container driver.

@tonistiigi Given that, then why does the documentation say this under ---driver? I used --load using docker-container driver just as the documentation said:
docker buildx build -f sample.Dockerfile -t <tag> . --platform linux/amd64,linux/arm64,linux/arm/v7 --load
From that I got an error:

------
 > exporting to oci image format:
------
failed to solve: rpc error: code = Unknown desc = docker exporter does not currently support exporting manifest lists

I believe I misunderstood what the documentation was telling me, and it is like you said from above. Please correct me if I'm wrong, I'm brand new to all of this and I'm learning.

[tonistiigi]

@manofthelionarmy That seems unrelated. Current versions of Docker have no concept of a local multi-arch image, therefore there is no way to load them and load needs to happen single-arch at a time. Described in https://github.com/docker/buildx#docker . But this is unrelated to accessing images as base image.

[Shaked]

Hey @ishii1648 did you figure it out?

I am experiencing the same problem.

[jjlin]

The docker-container driver you need to use for multi-platform builds doesn't support accessing local images, so you need to pull from a registry, whether local or remote. You can run with a local registry by doing something like

# Run a local registry (https://hub.docker.com/_/registry) at localhost:5000.
$ docker run -d --name registry --network=host registry:2

# Push your image(s) to the local registry.
$ docker tag ubuntu:18.04 localhost:5000/ubuntu:18.04
$ docker push localhost:5000/ubuntu:18.04

# Create a `docker-container` builder with host networking.
$ docker buildx create --name builder --use --driver-opt network=host

# Build the image.
docker buildx build \
       --network=host \
       --build-arg LOCAL_REGISTRY="localhost:5000" \
       --platform linux/amd64,linux/arm64 \
       ...

with a Dockerfile like

ARG LOCAL_REGISTRY
FROM ${LOCAL_REGISTRY}/ubuntu:18.04
...

[re6exp]

I have the same problem. All is working, but no image is created in the local system.
Maybe we use this tool in the wrong way, do we?

[ndepal]

I'm running into the same issue. I understand the explanation, but I find the docker buildx build documentation quite confusing. Why is there the following option, if it always happens anyway and it is not possible to do anything else?

--pull  Always attempt to pull a newer version of the image

[tonistiigi]

If you don't specify --pull on docker driver (or buildkit with containerd worker) then local docker or containerd image will be used without pulling anything from the registry.

I'm closing this one as the initial question has been answered and other comments look unrelated to it. If something was left unanswered open a new issue.