Node to Node Docker Image Transfer

[t-lin]

For improved resiliance against Internet connectivity failures, it'd be ideal of allocators / docker engines could somehow get images from another node, rather than going to Docker hub all the time.

To support such a capability:

• Allocators should be able to report images currently held on node (may or may not be running)
• Allocators should be able to request transfer of image
• Actual transfer can be done either by:
  • Setting up a per-host registry (or a subset of hosts with good network connectivity and bandwidth + disk capacity)
  • Save the image to a file, copy it, then load it (may take longer than prior solution)

[t-lin]

Uber has a project on something similar: https://github.com/uber/kraken

Their architecture seems like it has a lot of parts, wondering if it can be deployed with fewer components and in a simplified manner, so we get just the features we need.

[t-lin]

If developing our own interface/protocol, can potentially use:

• Server side to upload: https://godoc.org/github.com/docker/docker/client#Client.ImageSave
• Client side to download: https://godoc.org/github.com/docker/docker/client#Client.ImageLoad

Alternatively, need to look into using IPFS's existing protocols and libraries. It supports a replication factor to ensure certain content are replicated a minimum number of times, an ideal feature for images.

• See here for potential starting point: https://godoc.org/github.com/ipfs/ipfs-cluster