Generated Provenance attestation does not follow SLSA provenance schema, version 0.2; subject and predicate missing

[vknarayan]

Description

Used OS is Ubuntu 22.04.2 LTS.

1. followed the documentation to install Docker engine manually. https://docs.docker.com/engine/install/ubuntu/#install-from-a-package
   sudo dpkg -i ./containerd.io_1.6.9-1_amd64.deb ./docker-ce_23.0.3-1_ubuntu.22.04_jammy_amd64.deb ./docker-ce-cli_23.0.3-1_ubuntu.22.04_jammy_amd64.deb ./docker-buildx-plugin_0.10.4-1_ubuntu.22.04_jammy_amd64.deb ./docker-compose-plugin_2.6.0_ubuntu-jammy_amd64.deb
2. Overwrote docker cli built from master branch of this repo https://github.com/docker/cli/
3. followed the documentation given in this url: https://docs.docker.com/build/attestations/slsa-provenance/ to create the provenance attestation json, which is not in the same schema as SLSA provenance schema, version 0.2.

Reproduce

1. docker buildx create --name container --driver=docker-container
   container
2. docker buildx ls
   NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
   container docker-container
   container0 unix:///var/run/docker.sock inactive
   default * docker
   default default running 23.0.3 linux/amd64, linux/amd64/v2, linux/amd64/v3, linux/386
3. docker login
   ......
   Login Succeeded
4. cat Dockerfile
   FROM alpine
   CMD ["echo", "Hello StackOverflow!"]
5. DOCKER_BUILDKIT=1 docker buildx build --tag opsmx11/prov:v2 --push --attest type=provenance,mode=min,generator=image --builder=container .
   [+] Building 5.6s (7/7) FINISHED
   => [internal] load .dockerignore 0.0s
   => => transferring context: 2B 0.0s
   => [internal] load build definition from Dockerfile 0.0s
   => => transferring dockerfile: 86B 0.0s
   => [internal] load metadata for docker.io/library/alpine:latest 1.8s
   => [auth] library/alpine:pull token for registry-1.docker.io 0.0s
   => [1/1] FROM docker.io/library/alpine@sha256:124c7d2707904eea7431fffe91522a01e5a861a624ee31d03372cc1d138a3126 0.0s
   => => resolve docker.io/library/alpine@sha256:124c7d2707904eea7431fffe91522a01e5a861a624ee31d03372cc1d138a3126 0.0s
   => exporting to image 3.7s
   => => exporting layers 0.0s
   => => exporting manifest sha256:da8eed841d8afeba7655c7a8903f03d5f112b97a8e52b12d52ee3df35b31d3e7 0.0s
   => => exporting config sha256:ca240bf06400b2bacbba75ba3ba2abab460717559c07a42318f7922e48a48302 0.0s
   => => exporting attestation manifest sha256:1c7a48f2b9a3cd260a22e0f9b30a6f7c73556a5a0fdd360117cd0ed70b0c4383 0.0s
   => => exporting manifest list sha256:2d35bafec6bd5e73dde42cd8eca3bfee8de11178c455a37e28370d34faf5bb82 0.0s
   => => pushing layers 2.0s
   => => pushing manifest for docker.io/opsmx11/prov:v2@sha256:2d35bafec6bd5e73dde42cd8eca3bfee8de11178c455a37e28370d34faf5bb82 1.6s
   => [auth] opsmx11/prov:pull,push token for registry-1.docker.io 0.0s
6. docker buildx imagetools inspect opsmx11/prov:v2 --format "{{ json .Provenance.SLSA }}"
   {
   "buildType": "https://mobyproject.org/buildkit@v1",
   "builder": {
   "id": ""
   },
   "invocation": {
   "configSource": {
   "entryPoint": "Dockerfile"
   },
   "environment": {
   "platform": "linux/amd64"
   },
   "parameters": {
   "frontend": "dockerfile.v0",
   "locals": [
   {
   "name": "context"
   },
   {
   "name": "dockerfile"
   }
   ]
   }
   },
   "materials": [
   {
   "digest": {
   "sha256": "124c7d2707904eea7431fffe91522a01e5a861a624ee31d03372cc1d138a3126"
   },
   "uri": "pkg:docker/alpine@latest?platform=linux%2Famd64"
   }
   ],
   "metadata": {
   "buildFinishedOn": "2023-04-14T11:29:54.416420339Z",
   "buildInvocationID": "7avam11c99v99dwggp920n3w0",
   "buildStartedOn": "2023-04-14T11:29:52.551035942Z",
   "completeness": {
   "environment": true,
   "materials": false,
   "parameters": true
   },
   "https://mobyproject.org/buildkit@v1#metadata": {
   "vcs": {
   "revision": "1454aef05d05a448b6695897be7baa951ed6989d",
   "source": "https://github.com/gopaljayanthi/provenance.git"
   }
   },
   "reproducible": false
   }

Expected behavior

Output should be in SLSA provenance schema, Version 0.2, as shown below
{
// Standard attestation fields:
"_type": "https://in-toto.io/Statement/v0.1",
"subject": [{ ... }],

// Predicate:
"predicateType": "https://slsa.dev/provenance/v0.2",
"predicate": {
"builder": {
"id": ""
},
"buildType": "",
"invocation": {
"configSource": {
"uri": "",
"digest": { /* DigestSet / },
"entryPoint": ""
},
"parameters": { / object / },
"environment": { / object / }
},
"buildConfig": { / object / },
"metadata": {
"buildInvocationId": "",
"buildStartedOn": "",
"buildFinishedOn": "",
"completeness": {
"parameters": true/false,
"environment": true/false,
"materials": true/false
},
"reproducible": true/false
},
"materials": [
{
"uri": "",
"digest": { / DigestSet */ }
}
]
}
}

docker version

Client:
 Version:           24.0.0-beta.1-78-g60d0659e40.m
 API version:       1.42 (downgraded from 1.43)
 Go version:        go1.20.3
 Git commit:        60d0659e40
 Built:             Fri Apr 14 08:58:12 2023
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          23.0.3
  API version:      1.42 (minimum version 1.12)
  Go version:       go1.19.7
  Git commit:       59118bf
  Built:            Tue Apr  4 22:05:48 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.9
  GitCommit:        1c90a442489720eec95342e1789ee8a5e1b9536f
 runc:
  Version:          1.1.4
  GitCommit:        v1.1.4-0-g5fd4c4d
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:    24.0.0-beta.1-78-g60d0659e40.m
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.10.4
    Path:     /usr/local/lib/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.6.0
    Path:     /usr/libexec/docker/cli-plugins/docker-compose
  scan: Docker Scan (Docker Inc.)
    Version:  v0.7.0
    Path:     /usr/libexec/docker/cli-plugins/docker-scan

Server:
 Containers: 2
  Running: 1
  Paused: 0
  Stopped: 1
 Images: 2
 Server Version: 23.0.3
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 1c90a442489720eec95342e1789ee8a5e1b9536f
 runc version: v1.1.4-0-g5fd4c4d
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.15.0-69-generic
 Operating System: Ubuntu 22.04.2 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 31.21GiB
 Name: opsmx-blr-l-078
 ID: 7BES:UPJW:T2B2:UBRJ:W4V2:VHGP:ZBYN:IXQU:N2PS:VWMK:P6FX:3AZ2
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Username: opsmx11
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Additional Info

It is not clear how to generate the SLSA provenance attestation from the documentation. Please provide a step by step example for the same.

[tonistiigi]

This seems to be confusion around what the format string there means. It seems to be showing the predicate. The raw data is the full attestation, eg. https://explore.ggcr.dev/?blob=moby/buildkit@sha256:8ce6298d369f34dc10fadb47204d36cbb941fc58fbfb5268dd1776335d434e47&mt=application%2Fvnd.in-toto%2Bjson&size=39608