test out layer federation with docker

config.yml

version: 0.1
log:
  fields:
    service: registry
storage:
  cache:
    blobdescriptor: inmemory
  filesystem:
    rootdirectory: ./reg_store
http:
  addr: :5000
  host: myregistrydomain.com:5000
  headers:
    X-Content-Type-Options: [nosniff]
health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3
#validation:
  #enabled: true
  #manifests:
    #urls:
      #allow:
        #- ^https?://([^/]+\.)*runcom\.red/
      #deny:
        #- ^https?://www\.runcomtypo\.red/

instructions.sh

cd $GOPATH/src/github.com/projectatomic/skopeo
git remote add runcom https://github.com/runcom/skopeo
git fetch runcom -a
git checkout --track runcom/layerfed
make binary-local

cd $GOPATH/src/github.com/docker/distribution
git pull
make binaries
./bin/registry serve config.yml # config.yml is provided above

cd $GOPATH/src/github.com/projectatomic/skopeo
mkdir ./test
./skopeo copy docker://runcom/layerfed0 dir:test

# now edit ./test/manifest.json and use either "manifest_missing_layer" or "manifest_with_federated_layer"
# the difference is just that 1 layer is present on runcom.red, the other is not (to test what happens if the layer
# is missing)

# manifest_missing_layer
./skopeo --tls-verify=false --debug copy dir:test docker://myregistrydomain.com:5000/layerfedmissing

# re-edit the manifest again with manifest_with_federated_layer
./skopeo --tls-verify=false --debug copy dir:test docker://myregistrydomain.com:5000/layerfed

sudo rm -rf /var/lib/docker
# starting fresh...
# compile and install docker from https://github.com/docker/docker/pull/27961

docker pull myregistrydomain.com:5000/layerfed # you'll successfully fetch the layer from runcom.red/layer.tar
docker pull myregistrydomain.com:5000/layerfedmissing # you'll eventually get a timeout here

# for the sake of curiosity you can inspect the registry to see that the federated layer isn't present locally in the
# registry store
cd $GOPATH/src/github.com/docker/distribution
# now go into ./reg_store if you used the config.yml above
cd ./reg_store
find . | grep 56be
# nothing shows up, that 56be is the layer which is on runcom.red

manifest_missing_layer.json

{
   "schemaVersion": 2,
   "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
   "config": {
      "mediaType": "application/vnd.docker.container.image.v1+json",
      "size": 1784,
      "digest": "sha256:baf06652cc36be49f25c2e18163f8fa0a29f359ceddb08a753aebaa5d277fba4"
   },
   "layers": [
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "size": 668151,
         "digest": "sha256:56bec22e355981d8ba0878c6c2f23b21f422f30ab0aba188b54f1ffeff59c190",
	 "urls": [
		"https://runcom.red/layer_not_exists.tar"
	 ]
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "size": 110,
         "digest": "sha256:e55b504c4cb5ebda821866e5658f23fbd1184c4c75e60e7ba4d86807e0cab77a"
      }
   ]
}

manifest_with_federated_layer.json

{
   "schemaVersion": 2,
   "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
   "config": {
      "mediaType": "application/vnd.docker.container.image.v1+json",
      "size": 1784,
      "digest": "sha256:baf06652cc36be49f25c2e18163f8fa0a29f359ceddb08a753aebaa5d277fba4"
   },
   "layers": [
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "size": 668151,
         "digest": "sha256:56bec22e355981d8ba0878c6c2f23b21f422f30ab0aba188b54f1ffeff59c190",
	 "urls": [
		"https://runcom.red/layer.tar"
	 ]
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "size": 110,
         "digest": "sha256:e55b504c4cb5ebda821866e5658f23fbd1184c4c75e60e7ba4d86807e0cab77a"
      }
   ]
}

RHEL requirements:

• yum install gpgme-devel libassuan-devel
• comment out offending crypto curve per https://bugzilla.redhat.com/show_bug.cgi?id=1038683