A tool to convert images saved from docker save to oci format image.
For go up to version 1.17, use:
go get github.com/coolljt0725/docker2oci
For go version 1.17+, use:
go install github.com/coolljt0725/docker2oci@latest
To build docker2oci, the following build system dependencies are required:
- Go 1.8.x or above
- vndr tool
Build steps:
$ git clone https://github.com/coolljt0725/docker2oci $GOPATH/src/github.com/coolljt0725/docker2oci
$ cd $GOPATH/src/github.com/coolljt0725/docker2oci
$ make
$ docker save -o busybox.tar busybox
$ docker2oci -i busybox.tar busybox
or
$ docker save busybox | docker2oci busybox
Check the the image:
$ find busybox -type f
busybox/blobs/sha256/8baf43d43a34a0e6649c254b0200c2406fc40a501a852ba51a86ac3672dc0441
busybox/blobs/sha256/40a114053d955a2b80ee2cf6e13410b28b59594ceee9036b41e12c42d3e16615
busybox/blobs/sha256/8ac8bfaff55af948c796026ee867448c5b5b5d9dd3549f4006d9759b25d4a893
busybox/index.json
busybox/oci-layout
$ oci-image-tool validate busybox
oci-image-tool: reference "latest": OK
busybox: OK
Validation succeeded
$ mkdir bundle
$ oci-image-tool create --ref latest busybox bundle/
$ ls bundle/
config.json rootfs
It also work if docker save save serveral images.
$ docker images busybox
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox v2 0f4cf98c1107 4 minutes ago 1.09MB
busybox v1 df8dde2cf4ad 4 minutes ago 1.09MB
busybox latest 2b8fd9751c4c 13 months ago 1.09MB
$ docker save busybox | ./docker2oci busybox
$ oci-image-tool validate busybox
oci-image-tool: reference "latest": OK
oci-image-tool: reference "v1": OK
oci-image-tool: reference "v2": OK
busybox: OK
Validation succeeded