IPDR: InterPlanetary Docker Registry

IPFS-backed Docker Registry

IPDR is a Docker Registry tool that proxies Docker registry requests to IPFS for pushing and pulling images. IPDR allows you to store Docker images on IPFS instead of a central registry like Docker Hub or Google Container Registry. Docker images are referenced by their IPFS hash instead of the repo tag names.

IPDR is compatabile with the Docker Registry HTTP API V2 Spec for pulling images*

^{_{*not fully 1:1 implemented yet}}

High-level overview:

Contents

• Install
• Getting started
• CLI
• Test
• FAQ
• Contributing
• Resources
• License

Install

• Install with Go:

  go get -u github.com/ipdr/ipdr/cmd/ipdr

• Install from release binaries:

  # replace x.x.x with the latest version
  wget https://github.com/ipdr/ipdr/releases/download/x.x.x/ipdr_x.x.x_linux_amd64.tar.gz
  tar -xvzf ipdr_x.x.x_linux_amd64.tar.gz ipdr
  ./ipdr --help
  
  # move to bin path
  sudo mv ipdr /usr/local/bin/ipdr

Getting started

Prerequisites

• Start IPFS daemon (Install instructions):

  $ ipfs daemon
  Initializing daemon...
  Swarm listening on /ip4/127.0.0.1/tcp/4001
  Swarm listening on /ip4/192.168.86.90/tcp/4001
  Swarm listening on /ip6/::1/tcp/4001
  Swarm listening on /p2p-circuit/ipfs/QmR29wrbNv3WrMuodwuLiDwvskuZKKeTtcYDw7SwNffzCH
  Swarm announcing /ip4/127.0.0.1/tcp/4001
  Swarm announcing /ip4/192.168.0.21/tcp/43042
  Swarm announcing /ip4/192.168.86.90/tcp/4001
  Swarm announcing /ip6/::1/tcp/4001
  API server listening on /ip4/0.0.0.0/tcp/5001
  Gateway (readonly) server listening on /ip4/0.0.0.0/tcp/8080
  Daemon is ready

• Add docker.local to /etc/hosts:

  echo '127.0.0.1 docker.local' | sudo tee -a /etc/hosts
  echo '::1       docker.local' | sudo tee -a /etc/hosts

  • Flush local DNS cache:

    • on macOS:

      dscacheutil -flushcache; sudo killall -HUP mDNSResponder

    • on Ubuntu 18+:

      sudo systemd-resolve --flush-caches

Example flow

• Create Dockerfile:

  FROM busybox:latest
  
  CMD echo 'hello world'

• Build Docker image:

  docker build -t example/helloworld .

  Test run:

  $ docker run example/helloworld:latest
  hello world

• Use IPDR CLI to push to IPFS:

  $ ipdr push example/helloworld
  
  INFO[0000] [registry] temp: /var/folders/k1/m2rmftgd48q97pj0xf9csdb00000gn/T/205139235
  INFO[0000] [registry] preparing image in: /var/folders/k1/m2rmftgd48q97pj0xf9csdb00000gn/T/657143846
  INFO[0000]
  [registry] dist: /var/folders/k1/m2rmftgd48q97pj0xf9csdb00000gn/T/657143846/default/blobs/sha256:305510b2c684403553fd8f383e8d109b147df2cfde60e40a85564532c383c8b8
  INFO[0000] [registry] compressing layer: /var/folders/k1/m2rmftgd48q97pj0xf9csdb00000gn/T/205139235/886f4bdfa483cc176e947c63d069579785c051793a9634f571fded7b9026cd3c/layer.tar
  INFO[0000] [registry] root dir: /var/folders/k1/m2rmftgd48q97pj0xf9csdb00000gn/T/657143846
  INFO[0000] [registry] upload hash QmRxZ5Wffj6b1j8ckJLcr7yFrbHUhBYXsAMbj7Krwu1pp8
  INFO[0000]
  [registry] uploaded to /ipfs/Qmc2ot2NQadXmbvPbsidyjYDvPfPwKZmovzNpfRPKxXUrL
  INFO[0000] [registry] docker image ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi
  
  Successfully pushed Docker image to IPFS:
  /ipfs/Qmc2ot2NQadXmbvPbsidyjYDvPfPwKZmovzNpfRPKxXUrL

• Use IPDR CLI to pull from IPFS:

  $ ipdr pull QmagW4H1uE5rkm8A6iVS8WuiyjcWQzqXRHbM3KuUfzrCup
  
  INFO[0000] [registry/server] port 5000
  INFO[0000] [registry] attempting to pull docker.local:5000/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi
  INFO[0000] [registry/server] /v2/
  INFO[0000] [registry/server] /v2/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi/manifests/latest
  INFO[0000] [registry/server] location http://127.0.0.1:8080/ipfs/Qmc2ot2NQadXmbvPbsidyjYDvPfPwKZmovzNpfRPKxXUrL/manifests/latest-v2
  {"status":"Pulling from ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi","id":"latest"}
  {"status":"Digest: sha256:1fb36e4704d6ebad5becdcfe996807de5f8db687da396330f112157c888c165b"}
  {"status":"Status: Downloaded newer image for docker.local:5000/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi:latest"}
  
  Successfully pulled Docker image from IPFS:
  docker.local:5000/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi

• Run image pulled from IPFS:

  $ docker run docker.local:5000/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi
  hello world

• Retag Docker image:

  $ docker tag docker.local:5000/ciqmw4mig2uwaygddjlutoywq43udutvdmuxkcxvetsjp2mjdde27wi example/helloworld:latest

• We can also pull the image using docker pull:

  • First run the IPDR server in a seperate terminal:

    $ ipdr server -p 5000
    INFO[0000] [registry/server] listening on [::]:5000

  • Then convert the IPFS hash to a valid format docker allows:

    $ ipdr convert QmYMg6WAuvF5i5yFmjT8KkqewZ5Ngh4U9Mp1bGfdjraFVk --format=docker
    
    ciqjjwaeoszdgcaasxmlhjuqnhbctgwijqz64w564lrzeyjezcvbj4y

  • Now we can docker pull the image from IPFS:

    $ docker pull docker.local:5000/ciqjjwaeoszdgcaasxmlhjuqnhbctgwijqz64w564lrzeyjezcvbj4y
    Using default tag: latest
    latest: Pulling from ciqjjwaeoszdgcaasxmlhjuqnhbctgwijqz64w564lrzeyjezcvbj4y
    Digest: sha256:6b787c9e04c2038d4b3cb0392417abdddfcfd88e10005d970fc751cdcfd6d895
    Status: Downloaded newer image for docker.local:5000/ciqjjwaeoszdgcaasxmlhjuqnhbctgwijqz64w564lrzeyjezcvbj4y:latest

    Test run:

    $ docker run docker.local:5000/ciqjjwaeoszdgcaasxmlhjuqnhbctgwijqz64w564lrzeyjezcvbj4y
    hello world

TLDR; example

# build Docker image
docker build -t example/helloworld .

# push to IPFS
IPFS_HASH="$(ipdr push example/helloworld --silent)"

# pull from IPFS
REPO_TAG=$(ipdr pull "$IPFS_HASH" --silent)

# run image pulled from IPFS
docker run "$REPO_TAG"

CLI

$ ipdr --help

The command-line interface for the InterPlanetary Docker Registry.
More info: https://github.com/ipdr/ipdr

Usage:
  ipdr [flags]
  ipdr [command]

Available Commands:
  convert     Convert a hash to IPFS format or Docker registry format
  help        Help about any command
  pull        Pull image from the IPFS-backed Docker registry
  push        Push image to IPFS-backed Docker registry
  server      Start IPFS-backed Docker registry server

Flags:
  -h, --help   help for ipdr

Use "ipdr [command] --help" for more information about a command.

IPNS

An example of using IPNS to resolve image tag names.

1. First start local server:

ipdr server -p 5000

2. Tag the image:

docker pull hello-world
docker tag hello-world docker.local:5000/hello-world

3. Push to local registry:

docker push --quiet docker.local:5000/hello-world

CID mappings live under ~/.ipdr

$ tree ~/.ipdr/
/home/username/.ipdr/
└── cids
    └── hello-world
        └── latest

4. Add cids directory to IPFS:

$ ipfs add -r ~/.ipdr/cids/ --quieter
QmVtjwa3kdFJHce2wnFuygaCHdSPXraBd4FRSEZKjqZWQp

5. Set _dnslink TXT record on the domain to point to the directory IPFS hash:

dnslink=/ipfs/QmVtjwa3kdFJHce2wnFuygaCHdSPXraBd4FRSEZKjqZWQp

6. Verify DNS changes:

$ dig _dnslink.example.com -t TXT +short
"dnslink=/ipfs/QmVtjwa3kdFJHce2wnFuygaCHdSPXraBd4FRSEZKjqZWQp"

7. Re-run server, now with domain as resolver:

$ ipdr server --cid-resolver=example.com

8. Now we can run ipdr dig to get CID using repo tag name!

$ ipdr dig hello-world:latest
bafybeiakvswzlopeu573372p5xry47tkc2hhcg5q5rulmbfrnkecrbnt3y

Note: if nothing is returned, then make sure the IPFS gateway is correct.

9. Next pull and the docker image from IPFS using the resolved CID formatted for docker:

docker pull docker.local:5000/bafybeiakvswzlopeu573372p5xry47tkc2hhcg5q5rulmbfrnkecrbnt3y
docker run docker.local:5000/bafybeiakvswzlopeu573372p5xry47tkc2hhcg5q5rulmbfrnkecrbnt3y

Test

make test

Development

CompileDaemon -command="./build/ipdr" --directory="./" --color=true --build="go build -o build/ipdr ./cmd/ipdr"
./build/ipdr ...

FAQ

• Q: How do I configure the local registry host or port that IPDR uses when pushing or pulling Docker images?

  • A: Use the --docker-registry-host flag, eg. --docker-registry-host docker.for.mac.local:5000

• Q: How do I configure the IPFS host that IPDR uses for pushing Docker images?

  • A: Use the --ipfs-host flag, eg. --ipfs-host 127.0.0.1:5001

• Q: How do I configure the IPFS gateway that IPDR uses for pulling Docker images?

  • A: Use the --ipfs-gateway flag, eg. --ipfs-gateway https://ipfs.io

• Q: How can I configure the port for the IPDR registry server?

  • A: Use the --port flag, eg. --port 5000

• Q: How do I setup HTTPS/TLS on the IPDR registry server?

  • A: Use the --tlsKeyPath and --tlsCertPath flag, eg. --tlsKeyPath path/server.key --tlsCertPath path/server.crt

• Q: How do I get docker.local to work?

  • A: Make sure to add 127.0.0.1 docker.local to /etc/hosts. Optionally, you may use local.ipdr.io which resolves to 127.0.0.1

Contributing

Pull requests are welcome!

For contributions please create a new branch and submit a pull request for review.

Many thanks to @qiangli and all the contributors that made this package better.

Social

• Discuss on Discord

Resources

• Docker Registry HTTP API V2 Spec
• Docker Registry 2.0 (slidedeck)
• image2ipfs

License

Released under the MIT license.

© Miguel Mota