Error saving Docker images to AWS S3 bucket from private Docker Registry

Question

I'm trying to set up a private Docker Registry and save images to AWS S3 instance. The Registry seems to be working fine -- it starts up ok and I can authenticate to it over https. The problem I'm having is that I'm getting an error saving to S3, so I assume there is some permission problem with the S3 IAM policy.

The docker run command looks like this:

docker run -p 443:5000 \
  --link redis:redis \
  -e REGISTRY_STORAGE=s3 \
  -e REGISTRY_STORAGE_S3_BUCKET=my-docker-registry \
  -e REGISTRY_STORAGE_S3_ACCESSKEY=**** \
  -e REGISTRY_STORAGE_S3_SECRETKEY=**** \
  -e REGISTRY_STORAGE_S3_REGION=us-east-1 \
  -v `pwd`/auth:/auth \
  -e REGISTRY_AUTH=htpasswd \
  -e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
  -e REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd \
  -v `pwd`/certs:/certs \
  -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/my.com_chain.crt \
  -e REGISTRY_HTTP_TLS_KEY=/certs/my.com.key \
  -e REGISTRY_STORAGE_CACHE_BLOBDESCRIPTOR=redis \
  -e REGISTRY_REDIS_ADDR=redis:6379 \
  registry:2.5

And the S3 IAM policy looks like this:

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListAllMyBuckets"
         ],
         "Resource":"arn:aws:s3:::*"
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListBucket",
            "s3:GetBucketLocation"
         ],
         "Resource":"arn:aws:s3:::my-docker-registry"
      },
      {
         "Effect":"Allow",
         "Action":[
              "s3:PutObject",
              "s3:GetObject",
              "s3:DeleteObject",
              "s3:ListMultipartUploadParts",
              "s3:AbortMultipartUpload"
         ],
         "Resource":"arn:aws:s3:::my-docker-registry/*"
      }
   ]
}

The error log entry is:

level=error msg="error resolving upload: s3aws: AccessDenied: Access Denied\n\tstatus code: 403, request id: 2B224..." auth.user.name=my-user go.version=go1.6.3 http.request.host=my.domain.com http.request.id=13b79c07-... http.request.method=PATCH http.request.remoteaddr="xx.xx.xx.xx:41392" http.request.uri="/v2/my-test/blobs/uploads/467d94ea-2a77...?_state=zQd-..." http.request.useragent="docker/1.12.0 go/go1.6.3 git-commit/8eab123 kernel/4.4.15-moby os/linux arch/amd64 UpstreamClient(Docker-Client/1.12.0 \\(darwin\\))" instance.id=8a8db6f1-8fe4 vars.name=my-test vars.uuid=467d94ea-2a77 version=v2.5.0

I've used a similar policy for file uploads in other apps, so I'm not sure where the problem is. What do I need to change in the IAM policy to allow the registry to save to the S3 bucket?

Answer 1

I figured it out - not sure if something changed with how Docker saves image files but it seems you now need to add s3:ListBucketMultipartUploads to the bucket-level permission (middle block below, IAM shown in full for completeness):

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListAllMyBuckets"
         ],
         "Resource":"arn:aws:s3:::*"
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListBucket",
            "s3:GetBucketLocation",
            "s3:ListBucketMultipartUploads"
         ],
         "Resource":"arn:aws:s3:::my-docker-registry"
      },
      {
         "Effect":"Allow",
         "Action":[
              "s3:PutObject",
              "s3:GetObject",
              "s3:DeleteObject",
              "s3:ListMultipartUploadParts",
              "s3:AbortMultipartUpload"
         ],
         "Resource":"arn:aws:s3:::my-docker-registry/*"
      }
   ]
}

Seems to work well now.

Next steps are to create a docker-compose file with the above docker run args, add a redis container to that, and it's a full private registry solution.