This is a simple script to convert a Singularity image back to Docker, preserving environment, labels, and runscript. The usage is as follows:
./singularity2docker.sh -n newcontainer:tag singularity-container.sifThe above says "Create a new container called newcontainer:tag (-n == name) from
the Singularity container singularity-container.sif The other argument you can provide
to skip cleanup of the sandbox (if you intend to build again) is --no-cleanup.
- Singularity
- Docker
- jq
$ ./singularity2docker.sh -n newcontainer:tag singularity-container.sif
Input Image: singularity-container.sif
1. Checking for software dependencies, Singularity and Docker...
Found Singularity 2.4.5-master.g0b17e18
Found Docker Docker version 18.03.0-ce, build 0520e24
2. Preparing sandbox for export...
3. Exporting metadata...
Adding LABEL "MAINTAINER" vanessasaur
Adding LABEL "WHATAMI" dinosaur
Adding LABEL "org.label-schema.build-date" 2017-10-15T12:52:56+00:00
Adding LABEL "org.label-schema.build-size" 333MB
Adding LABEL "org.label-schema.schema-version" 1.0
Adding LABEL "org.label-schema.usage.singularity.deffile" Singularity
Adding LABEL "org.label-schema.usage.singularity.deffile.bootstrap" docker
Adding LABEL "org.label-schema.usage.singularity.deffile.from" ubuntu:14.04
Adding LABEL "org.label-schema.usage.singularity.version" 2.4-feature-squashbuild-secbuild.g780c84d
Adding command...
4. Build away, Merrill!
Created container newcontainer:tag
docker inspect newcontainer:tag
$ docker inspect newcontainer:tag
[
{
"Id": "sha256:377b2e59f677aa68281322d55861b8ff22674fce05e76e691030555395c6d5d9",
"RepoTags": [
"container:new",
"newcontainer:tag"
],
"RepoDigests": [],
"Parent": "sha256:fbe2938963526faecb876ed31486ed024d6251f6aaad926b1993e4f3548903f5",
"Comment": "",
"Created": "2018-04-11T03:41:08.255990981Z",
"Container": "35f0fc90680a49c47868cc74cd54ccd0ecef539c9634ae5f735c9bed31e74763",
"ContainerConfig": {
"Hostname": "35f0fc90680a",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"LD_LIBRARY_PATH=/.singularity.d/libs"
],
"Cmd": [
"/bin/sh",
"-c",
"#(nop) ",
"CMD [\"/bin/bash\" \"run_singularity2docker.sh\"]"
],
"ArgsEscaped": true,
"Image": "sha256:fbe2938963526faecb876ed31486ed024d6251f6aaad926b1993e4f3548903f5",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
"MAINTAINER": "vanessasaur",
"WHATAMI": "dinosaur",
"org.label-schema.build-date": "2017-10-15T12:52:56+00:00",
"org.label-schema.build-size": "333MB",
"org.label-schema.schema-version": "1.0",
"org.label-schema.usage.singularity.deffile": "Singularity",
"org.label-schema.usage.singularity.deffile.bootstrap": "docker",
"org.label-schema.usage.singularity.deffile.from": "ubuntu:14.04",
"org.label-schema.usage.singularity.version": "2.4-feature-squashbuild-secbuild.g780c84d"
}
},
"DockerVersion": "18.03.0-ce",
"Author": "",
"Config": {
"Hostname": "",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"LD_LIBRARY_PATH=/.singularity.d/libs"
],
"Cmd": [
"/bin/bash",
"run_singularity2docker.sh"
],
"ArgsEscaped": true,
"Image": "sha256:fbe2938963526faecb876ed31486ed024d6251f6aaad926b1993e4f3548903f5",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
"MAINTAINER": "vanessasaur",
"WHATAMI": "dinosaur",
"org.label-schema.build-date": "2017-10-15T12:52:56+00:00",
"org.label-schema.build-size": "333MB",
"org.label-schema.schema-version": "1.0",
"org.label-schema.usage.singularity.deffile": "Singularity",
"org.label-schema.usage.singularity.deffile.bootstrap": "docker",
"org.label-schema.usage.singularity.deffile.from": "ubuntu:14.04",
"org.label-schema.usage.singularity.version": "2.4-feature-squashbuild-secbuild.g780c84d"
}
},
"Architecture": "amd64",
"Os": "linux",
"Size": 187796668,
"VirtualSize": 187796668,
"GraphDriver": {
"Data": null,
"Name": "aufs"
},
"RootFS": {
"Type": "layers",
"Layers": [
"sha256:a8d50d7688e2b24b2de0f779f63104f3dbe08e0ddff2658f01f81ffc2d0654be"
]
},
"Metadata": {
"LastTagTime": "2018-04-11T00:02:54.777906654-04:00"
}
}
]
$ docker run newcontainer:tag
RaawwWWWWWRRRR!!
$ singularity run singularity-container.sif
RaawwWWWWWRRRR!!
Rawr!