README.md

nydus-backend-proxy

A simple HTTP server to serve a local directory as blob backend for nydusd.

In some scenarios such as sealer, it uses nydus to boost up cluster image distribution. There is no registry (OCI distribution) or OSS service available for blob storage, so we need a simple HTTP server to serve a local directory as blob backend for nydusd. This server exposes OCI distribution like API to handle HTTP HEAD and range GET requests from nydusd for checking and fetching blob.

Definition for response

support the following APIs:

HEAD /$namespace/$repo/blobs/sha256:xxx ### Check Blob
GET /$namespace/$repo/blobs/sha256:xxx ### Fetch Blob

Check Blob

HEAD /v2/<name>/blobs/<digest>

On Success: OK

200 OK
Content-Length: <length of blob>
Docker-Content-Digest: <digest>

Fetch Blob

GET /v2/<name>/blobs/<digest>
Host: <registry host>

On Success: OK

200 OK
Content-Length: <length>
Docker-Content-Digest: <digest>
Content-Type: application/octet-stream

<blob binary data>

On Failure: Not Found

404 Not Found

Fetch Blob in Chunks

GET /v2/<name>/blobs/<digest>
Host: <registry host>
Range: bytes=<start>-<end>

On Success: OK

200 OK
Content-Length: <length>
Docker-Content-Digest: <digest>
Content-Range: bytes <start>-<end>/<size>
Content-Type: application/octet-stream

<blob binary data>

On Failure: Not Found

404 Not Found

On Failure: Range Not Satisfiable

416 Range Not Satisfiable

How to use

Run nydus-backend-proxy

./nydus-backend-proxy --blobsdir /path/to/nydus/blobs/dir

Nydusd config

reuse nydusd registry backend

#cat httpserver.json
{
  "device": {
    "backend": {
      "type": "registry",
      "config": {
        "scheme": "http",
	"host": "xxx.xxx.xxx.xxx:8000",
	"repo": "xxxx"
      }
    },
    "cache": {
      "type": "blobcache",
      "config": {
        "work_dir": "./cache"
      }
    }
  },
  "mode": "direct",
  "digest_validate": false,
  "enable_xattr": true,
  "fs_prefetch": {
    "enable": true,
    "threads_count": 2,
    "merging_size": 131072,
    "bandwidth_rate":10485760
  }
}