Is it possible to use the plugin with buildx?

[lamba92]

I'd be in need to automate a multiarch build similar to this example. Is there any task available?

[ArvinB]

Same here, this is becoming more important to use buildx as support for multi-architecture builds and pushing list (fat) manifests are increasingly being done.

[yuanjinyong]

    project.tasks.docker.with {
        commandLine getDockerBuildCmd()
        doFirst { logger.lifecycle("${commandLine.join(' ')}") }
    }

def getDockerBuildCmd() {
    def buildCommandLine = ['docker', 'buildx', 'build', '--load', '--platform', 'linux/amd64']
    if (docker.noCache) {
        buildCommandLine.add '--no-cache'
    }
    if (docker.network != null) {
        buildCommandLine.addAll('--network', docker.network)
    }
    if (!docker.buildArgs.isEmpty()) {
        for (Map.Entry<String, String> buildArg : docker.buildArgs.entrySet()) {
            buildCommandLine.addAll('--build-arg', "${buildArg.getKey()}=${buildArg.getValue()}")
        }
    }
    if (!docker.labels.isEmpty()) {
        for (Map.Entry<String, String> label : docker.labels.entrySet()) {
            if (!label.getKey().matches(LABEL_KEY_PATTERN)) {
                throw new GradleException(String.format("Docker label '%s' contains illegal characters. " +
                        "Label keys must only contain lowercase alphanumberic, `.`, or `-` characters (must match %s).",
                        label.getKey(), LABEL_KEY_PATTERN.pattern()))
            }
            buildCommandLine.addAll('--label', "${label.getKey()}=${label.getValue()}")
        }
    }
    if (docker.pull) {
        buildCommandLine.add '--pull'
    }
    buildCommandLine.addAll('-t', docker.name, '.')
    return buildCommandLine
}

[ArvinB]

This is great to see. I couldn't wait, so I ended up creating my own Gradle plugin with a focus on using docker buildx.

There were many many lessons learned along the way. Just a couple gotchas:

• On a RHEL VM, often the buildkit needs to be reset otherwise you loose multi-platform capabilities. Especially when the VM reboots.

docker run --rm --privileged multiarch/qemu-user-static --reset --persistent yes

• When you tag multi-platform images (which you should), then you have to revert to old-school for creating the list manifest. After the images are pushed to a registry of course.

docker manifest create --amend <your tagged image>
docker manifest push --purge <your tagged list manifest>