Unable to push an image to ECR about packer-plugin-docker HOT 6 OPEN

Yes, I got it working by installing Docker Desktop which setup /var/run/docker.sock. That is a workaround, though. Docker Desktop should not be a requirement for the Packer docker-push post-processor, as it is not for the builder or other post-processors. docker-push should correctly ascertain and use the active Docker endpoint based on the Docker context.

from packer-plugin-docker.

Just running into this myself, although I don't think it's specific to ECR. Rather it seems to be that docker-push does not respect the Docker context set nor have a way to specify the Docker context, and only uses the default context. Colima (and other container runtimes) specify alternate contexts as can be seen by running docker context ls. Example:

❯ docker context ls
NAME       DESCRIPTION                               DOCKER ENDPOINT
colima *   colima                                    unix:///Users/smaddock/.colima/default/docker.sock
default    Current DOCKER_HOST based configuration   unix:///var/run/docker.sock

This is why docker push works manually but the post processor does not. Note that this is a different issue than running Packer on a remote host... the host is still local; the socket is just in an alternate location.

from packer-plugin-docker.

Documentation: https://docs.docker.com/engine/context/working-with-contexts/

If we could set the DOCKER_CONTEXT environment variable, or the --context command-line argument like we can with run_command on the builder, that would work.

from packer-plugin-docker.

This might be a Mac specific problem. I just noticed that there is more than one context with Docker Desktop:

NAME              DESCRIPTION                               DOCKER ENDPOINT                                 ERROR
default           Current DOCKER_HOST based configuration   unix:///var/run/docker.sock
desktop-linux *   Docker Desktop                            unix:///Users/wawrzek/.docker/run/docker.sock

and Rancher Desktop has own:

rancher-desktop   Rancher Desktop moby context              unix:///Users/wawrzek/.rd/docker.sock

I'll check @smaddock your suggestion to set DOCKER_CONTEXT.

from packer-plugin-docker.

After setting the DOCKER_CONTEXT I see now a different error:

    docker.eigenlayer (docker-push): Failed to initialize: unable to resolve docker endpoint: context "desktop-linux": context not found: open /var/folders/l4/0bhk3tfj2dqg60yp93c7dtl00000gn/T/packer1747910882/contexts/meta/fe9c6bd7a66301f49ca9b6a70b217107cd1284598bfc254700c989b916da791e/meta.json: no such file or directory
    docker.eigenlayer (docker-push): Removing temporary Docker configuration directory

from packer-plugin-docker.

During further investigation, I fixed the default context in Docker Desktop. In my case it was pointing ad the socket from Rancher Desktop which was broken. I deleted '/var/run/docker.sock', disabled and then re-enabled Allow the default Docker socket to be used (requires password) option in the Docker Desktop Advance Settings. Default context (builder in Docker Desktop) was fixed, and then I can run packer normally.

I suggest anyone with the problem to check if /var/run/docker.sock is valid and enabled in Docker Desktop.

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