Unpacking layer 5731199219418f175d1580dbca05677e69144425b2d9ecb60f416cd57ca3ca42/layer.tar
tar: Removing leading `/' from member names
Unpacking layer e2897bf34bb78c4a65736510204282d9f7ca258ba048c183d665bd0f3d24c5ec/layer.tar
tar: Removing leading `/' from member names
Unpacking layer 420aa5876dca4128cd5256da7dea0948e30ef5971712f82601718cdb0a6b4cda/layer.tar
tar: Removing leading `/' from member names
Unpacking layer ea5f4e620e7906c8ecbc506b5e6f46420e68d4b842c3303260d5eb621b5942e5/layer.tar
tar: Removing leading `/' from member names
Unpacking layer 65807b9abe8ab753fa97da8fb74a21fcd4725cc51e1b679c7973c97acd47ebcf/layer.tar
tar: Removing leading `/' from member names
Unpacking layer b7da2076b60ebc0ea6824ef641978332b8ac908d47b2d07ff31b9cc362245605/layer.tar
Executing post-mount steps...
Packing raw image...
[    1.660036] reboot: Power down
/nix/store/x6a5m7c6zdpqz1d8j7cnzpx9glzzvd2h-hello
```

The following command lists some of the contents of the output to verify that the structure of the archive is as expected:

```shell
$ tar --exclude '*/share/*' --exclude 'nix/store/*/*' -tvf /nix/store/x6a5m7c6zdpqz1d8j7cnzpx9glzzvd2h-hello
drwxr-xr-x root/0            0 1979-12-31 16:00 ./
drwxr-xr-x root/0            0 1979-12-31 16:00 ./bin/
lrwxrwxrwx root/0            0 1979-12-31 16:00 ./bin/hello -> /nix/store/h92a9jd0lhhniv2q417hpwszd4jhys7q-hello-2.12.1/bin/hello
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/05zbwhz8a7i2v79r9j21pl6m6cj0xi8k-libunistring-1.1/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/ayg5rhjhi9ic73hqw33mjqjxwv59ndym-xgcc-13.2.0-libgcc/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/h92a9jd0lhhniv2q417hpwszd4jhys7q-hello-2.12.1/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/m59xdgkgnjbk8kk6k6vbxmqnf82mk9s0-libidn2-2.3.4/
dr-xr-xr-x root/0            0 1979-12-31 16:00 ./nix/store/p3jshbwxiwifm1py0yq544fmdyy98j8a-glibc-2.38-27/
drwxr-xr-x root/0            0 1979-12-31 16:00 ./share/
```
:::

:::{.example #ex-dockerTools-exportImage-importingDocker}
# Importing an archive built with `dockerTools.exportImage` in Docker

We will use the same package from [](#ex-dockerTools-exportImage-hello) and import it into Docker.

```nix
{ dockerTools, hello }:
dockerTools.exportImage {
  name = "hello";
  fromImage = dockerTools.buildLayeredImage {
    name = "hello";
    contents = [ hello ];
  };
}
```

Building and importing it into Docker:

```shell
$ nix-build
(output removed for clarity)
/nix/store/x6a5m7c6zdpqz1d8j7cnzpx9glzzvd2h-hello
$ docker image import /nix/store/x6a5m7c6zdpqz1d8j7cnzpx9glzzvd2h-hello
sha256:1d42dba415e9b298ea0decf6497fbce954de9b4fcb2984f91e307c8fedc1f52f
$ docker image ls
REPOSITORY                              TAG                IMAGE ID       CREATED         SIZE
<none>                                  <none>             1d42dba415e9   4 seconds ago   32.6MB
```
:::

:::{.example #ex-dockerTools-exportImage-naming}
# Exploring output naming with `dockerTools.exportImage`

`exportImage` does not require a `name` attribute if `fromImage` is a derivation, which means that the following works:

```nix
{ dockerTools, hello }:
dockerTools.exportImage {
  fromImage = dockerTools.buildLayeredImage {
    name = "hello";
    contents = [ hello ];
  };
}
```

However, since [`dockerTools.buildLayeredImage`](#ssec-pkgs-dockerTools-buildLayeredImage)'s output ends with `.tar.gz`, the output of `exportImage` will also end with `.tar.gz`, even though the archive created with `exportImage` is uncompressed:

```shell
$ nix-build
(output removed for clarity)
/nix/store/by3f40xvc4l6bkis74l0fj4zsy0djgkn-hello.tar.gz
$ file /nix/store/by3f40xvc4l6bkis74l0fj4zsy0djgkn-hello.tar.gz
/nix/store/by3f40xvc4l6bkis74l0fj4zsy0djgkn-hello.tar.gz: POSIX tar archive (GNU)
```

If the archive was actually compressed, the output of file would've mentioned that fact.