bake: enable support for entitlements

[tonistiigi]

Ref #179

Add support for security.insecure and network.host entitlements via bake. User needs to confirm elevated privileges through a prompt or CLI flags.

[tonistiigi]

Even though these additional entitlements are defined here, the current PR does not perform any validation for them yet.

[tonistiigi]

While the entitlements key in HCL is new and could not be used before, network: host was enabled via compose and may potentially break if entitlements is not passed by the user.

 # cat docker-compose.yml
services:
  app:
    build:
      network: "host"
 #
 # docker buildx bake app --print
[+] Building 0.0s (1/1) FINISHED
 => [internal] load local bake definitions                                                 0.0s
 => => reading docker-compose.yml 50B / 50B                                                0.0s
{
  "group": {
    "default": {
      "targets": [
        "app"
      ]
    }
  },
  "target": {
    "app": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "entitlements": [
        "network.host"
      ]
    }
  }
}
 # docker buildx bake app
[+] Building 0.0s (1/1) FINISHED
 => [internal] load local bake definitions                                                 0.0s
 => => reading docker-compose.yml 50B / 50B                                                0.0s
Your build is requesting privileges for following possibly insecure capabilities:

 - Running build containers that can access host network

In order to not see this message in the future pass "--allow=network.host" to grant requested privileges.

Your full command with requested privileges:

docker buildx bake --allow=network.host app

Do you want to grant requested privileges and continue? [y/N]

Additionally, I guess we now want to expose network = "host" via HCL/JSON as well? Note that the recommended way is for Dockerfile to define when it needs host network by setting RUN --network=host instead of overwriting the network for the whole build here.

[crazy-max]

While the entitlements key in HCL is new and could not be used before, network: host was enabled via compose and may potentially break if entitlements is not passed by the user.

I think this is fine looking at the recommendation printed during build.

Additionally, I guess we now want to expose network = "host" via HCL/JSON as well? Note that the recommended way is for Dockerfile to define when it needs host network by setting RUN --network=host instead of overwriting the network for the whole build here.

Yes we need that

[crazy-max]

If the idea is to check if buildx runs as docker plugin, then it would be better to check for !plugin.RunningStandalone()

[tonistiigi]

This isn't quite it. It is because when docker invokes the command then the arg is always docker-buildx so we shouldn't just replace it based on any command name.

But I now see that there is DOCKER_CLI_PLUGIN_ORIGINAL_CLI_COMMAND . I'll see if I can reuse it for this.

[crazy-max]

@dvdksn Seems a docs link is broken: https://github.com/docker/buildx/actions/runs/10636095098/job/29487219028?pr=2666#step:6:467

 #29 [validate-upstream 5/5] RUN htmltest
#29 0.066 htmltest started at 04:36:56 on public
#29 0.066 ========================================================================
#29 1.050 reference/cli/docker/buildx_bake/index.html
#29 1.050   hash does not exist --- reference/cli/docker/buildx_bake/index.html --> /build/attestations/slsa-provenance/#provenance-attestation-example
#29 1.050 reference/cli/docker/buildx_build/index.html
#29 1.205   hash does not exist --- reference/cli/docker/buildx_build/index.html --> /build/attestations/slsa-provenance/#provenance-attestation-example
#29 1.205 reference/cli/docker/buildx/build/index.html
#29 1.923   hash does not exist --- reference/cli/docker/buildx/build/index.html --> /build/attestations/slsa-provenance/#provenance-attestation-example
#29 1.923 reference/cli/docker/buildx/bake/index.html
#29 1.954   hash does not exist --- reference/cli/docker/buildx/bake/index.html --> /build/attestations/slsa-provenance/#provenance-attestation-example
#29 1.954 ========================================================================
#29 12.36 ✘✘✘ failed in 12.29200319s
#29 12.36 4 errors in 2598 documents

[dvdksn]

@crazy-max let me fix those in a follow-up

[tonistiigi]

I'm not sure what this error is about. buildx bake validate-docs passes for me locally.

[tonistiigi]

Looks like the docs thing went away. Green now.

[crazy-max]

Looks like the docs thing went away. Green now.

Yes this has been sorted with #2652