appc / docker2aci

library and CLI tool to convert Docker images to ACIs (archived, see https://github.com/rkt/rkt/issues/4024)

docker2aci - Convert docker images to ACI

docker2aci is a small library and CLI binary that converts Docker images to ACI. It takes as input either a file generated by "docker save" or a Docker registry URL. It gets all the layers of a Docker image and squashes them into an ACI image. Optionally, it can generate one ACI for each layer, setting the correct dependencies.

All ACIs generated are compressed with gzip by default. Compression can be disabled by specifying --compression=none.

Build

Requirements: golang 1.6+

git clone git://github.com/appc/docker2aci
cd docker2aci
./build.sh

Volumes

Docker Volumes get converted to mountPoints in the Image Manifest Schema. Since mountPoints need a name and Docker Volumes don't, docker2aci generates a name by appending the path to volume- replacing non-alphanumeric characters with dashes. That is, if a Volume has /var/tmp as path, the resulting mountPoint name will be volume-var-tmp.

When the docker2aci CLI binary converts a Docker Volume to a mountPoint it will print its name, path and whether it is read-only or not.

Ports

Docker Ports get converted to ports in the Image Manifest Schema. The resulting port name will be the port number and the protocol separated by a dash. For example: 6379-tcp.

CLI examples

$ docker2aci docker://busybox
Downloading sha256:55dc925c23d: [==============================] 674 KB/674 KB
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B

Generated ACI(s):
library-busybox-latest.aci
$ actool --debug validate library-busybox-latest.aci
library-busybox-latest.aci: valid app container image

$ /docker2aci --nosquash docker://quay.io/coreos/etcd:latest
Downloading sha256:f05e5379dcb: [==============================] 3.98 MB/3.98 MB
Downloading sha256:af1897d2d32: [==============================] 3.5 MB/3.5 MB
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B

Converted ports:
        name: "2379-tcp", protocol: "tcp", port: 2379, count: 1, socketActivated: false
        name: "2380-tcp", protocol: "tcp", port: 2380, count: 1, socketActivated: false
        name: "4001-tcp", protocol: "tcp", port: 4001, count: 1, socketActivated: false
        name: "7001-tcp", protocol: "tcp", port: 7001, count: 1, socketActivated: false

Generated ACI(s):
coreos-etcd-d21dd9a5886270b7c2c379c02fc548e0696b139c43bb12fdb2d9b63409717485-latest-linux-amd64-3.aci
coreos-etcd-620329641f386e62c7b0e0fa60a9acef100e71058124ddc7f1969557c72b2458-latest-linux-amd64-2.aci
coreos-etcd-9cd3f08f7ccfaad24c73757a5b4f79601f2790726d6ccdd556a82e5c9c5ddbfa-latest-linux-amd64-1.aci
coreos-etcd-9cd3f08f7ccfaad24c73757a5b4f79601f2790726d6ccdd556a82e5c9c5ddbfa-latest-linux-amd64-0.aci

$ docker save -o ubuntu.docker ubuntu
$ docker2aci ubuntu.docker
Extracting 706766fe1019
Extracting a62a42e77c9c
Extracting 2c014f14d3d9
Extracting b7cf8f0d9e82

Generated ACI(s):
ubuntu-latest.aci
$ actool --debug validate ubuntu-latest.aci
ubuntu-latest.aci: valid app container image

$ docker2aci docker://redis
Downloading sha256:c666c10c893: [==============================] 37.2 MB/37.2 MB
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:d6f52360d0a: [==============================] 1.69 KB/1.69 KB
Downloading sha256:8c3a687fd4c: [==============================] 5.93 MB/5.93 MB
Downloading sha256:15554e0e598: [==============================] 109 KB/109 KB 
Downloading sha256:3286d490a29: [==============================] 611 KB/611 KB 
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3d89b95a63: [==============================] 3.04 MB/3.04 MB
Downloading sha256:1c4db557158: [==============================] 98 B/98 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a1a961e320b: [==============================] 196 B/196 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B
Downloading sha256:a3ed95caeb0: [==============================] 32 B/32 B

Converted volumes:
        name: "volume-data", path: "/data", readOnly: false

Converted ports:
        name: "6379-tcp", protocol: "tcp", port: 6379, count: 1, socketActivated: false

Generated ACI(s):
library-redis-latest.aci
$ actool --debug validate library-redis-latest.aci
library-redis-latest.aci: valid app container image