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== Installation == | == Installation == | ||
To install docker, add the following to your your NixOS configuration: | |||
<syntaxHighlight lang=nix> | <syntaxHighlight lang=nix> | ||
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</syntaxHighlight> | </syntaxHighlight> | ||
Note: | Note: If you use the [[btrfs]] filesystem, you might need to set the storageDriver option: | ||
<syntaxHighlight lang=nix> | |||
virtualisation.docker.storageDriver = "btrfs" | |||
</syntaxHighlight> | |||
=== Rootless docker === | |||
To use docker in [https://docs.docker.com/engine/security/rootless/ rootless mode], you can activate the <code>rootless</code> option: | |||
<syntaxHighlight lang=nix> | |||
virtualisation.docker.rootless = { | |||
enable = true; | |||
setSocketVariable = true; | |||
}; | |||
</syntaxHighlight> | |||
The <code>setSocketVariable</code> option sets the <code>DOCKER_HOST</code> variable to the rootless Docker instance for normal users by default. | |||
== Building a docker image with nixpkgs == | == Building a docker image with nixpkgs == | ||
There is [https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools | There is an entry for [https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools dockerTools] in the nixpkgs manual for reference. | ||
In the | In the linked page they give the following example config: | ||
<syntaxHighlight lang=nix> | |||
buildImage { | |||
name = "redis"; | |||
tag = "latest"; | |||
fromImage = someBaseImage; | |||
fromImageName = null; | |||
fromImageTag = "latest"; | |||
copyToRoot = pkgs.buildEnv { | |||
name = "image-root"; | |||
paths = [ pkgs.redis ]; | |||
pathsToLink = [ "/bin" ]; | |||
}; | |||
Also check out the excellent article by | runAsRoot = '' | ||
#!${pkgs.runtimeShell} | |||
mkdir -p /data | |||
''; | |||
config = { | |||
Cmd = [ "/bin/redis-server" ]; | |||
WorkingDir = "/data"; | |||
Volumes = { "/data" = { }; }; | |||
}; | |||
diskSize = 1024; | |||
buildVMMemorySize = 512; | |||
} | |||
</syntaxHighlight> | |||
More examples can be found in the [https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/docker/examples.nix nixpkgs] repo. | |||
Also check out the excellent article by [http://lethalman.blogspot.de/2016/04/cheap-docker-images-with-nix_15.html lethalman] about building minimal docker images with nix. | |||
=== Reproducible image dates === | === Reproducible image dates === | ||
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An alternative, if using [[flakes]], is to do <code>created = builtins.substring 0 8 self.lastModifiedDate</code>, which uses the commit date, and is therefore reproducible. | An alternative, if using [[flakes]], is to do <code>created = builtins.substring 0 8 self.lastModifiedDate</code>, which uses the commit date, and is therefore reproducible. | ||
== How to calculate the <code>sha256</code> of a pulled image == | === How to calculate the <code>sha256</code> of a pulled image === | ||
The <code>sha256</code> argument of the <code>dockerTools.pullImage</code> function is the checksum of the archive generated by Skopeo. Since the archive contains the name and the tag of the image, Skopeo arguments used to fetch the image have to be identical to those used by the <code>dockerTools.pullImage</code> function. | The <code>sha256</code> argument of the <code>dockerTools.pullImage</code> function is the checksum of the archive generated by Skopeo. Since the archive contains the name and the tag of the image, Skopeo arguments used to fetch the image have to be identical to those used by the <code>dockerTools.pullImage</code> function. | ||
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1x00ks05cz89k3wc460i03iyyjr7wlr28krk7znavfy2qx5a0hfd | 1x00ks05cz89k3wc460i03iyyjr7wlr28krk7znavfy2qx5a0hfd | ||
</syntaxHighlight> | </syntaxHighlight> | ||
== Docker Compose with Nix == | == Docker Compose with Nix == | ||
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To use Arion, you first need to add its module to you NixOS configuration: | To use Arion, you first need to add its module to you NixOS configuration: | ||
<syntaxHighlight lang=nix> | |||
modules = [ arion.nixosModules.arion ]; | |||
</syntaxHighlight> | |||
After that you can access its options under | After that you can access its options under | ||
<syntaxHighlight lang=nix> | |||
virtualisation.arion = {} | |||
</syntaxHighlight> | |||
A config for a simple container could look like this: | A config for a simple container could look like this: | ||
<syntaxHighlight lang=nix> | |||
virtualisation.arion = { | |||
backend = "docker"; | |||
projects = { | |||
"db" = settings.services."db".service = { | |||
image = ""; | |||
restart = "unless-stopped"; | |||
environment = { POSTGRESS_PASSWORD = "password"; }; | |||
}; | }; | ||
}; | }; | ||
}; | |||
</syntaxHighlight> | |||
== Using Nix in containers == | |||
While [https://nixos.org/manual/nixpkgs/stable/#sec-pkgs-dockerTools dockerTools] allows to build lightweight containers, it requires <code>nix</code> to be installed on the host system. An alternative are docker images with nix preinstalled: | |||
* [https://hub.docker.com/r/nixos/nix/tags nixos/nix] (official) | |||
* [https://hub.docker.com/r/nixpkgs/nix nixpkgs/nix] (built from https://github.com/nix-community/docker-nixpkgs) | |||
== See also == | == See also == | ||