ociTools: init

This commit is contained in:
Katharina Fey 2019-08-30 15:46:38 +02:00 committed by Alyssa Ross
parent 43dade238f
commit 18f7f19ce2
4 changed files with 157 additions and 0 deletions

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@ -20,4 +20,5 @@
<xi:include href="functions/appimagetools.xml" />
<xi:include href="functions/prefer-remote-fetch.xml" />
<xi:include href="functions/nix-gitignore.xml" />
<xi:include href="functions/ocitools.xml" />
</chapter>

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@ -0,0 +1,76 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xi="http://www.w3.org/2001/XInclude"
xml:id="sec-pkgs-ociTools">
<title>pkgs.ociTools</title>
<para>
<varname>pkgs.ociTools</varname> is a set of functions for creating
containers according to the
<link xlink:href="https://github.com/opencontainers/runtime-spec">OCI
container specification v1.0.0</link>. Beyond that it makes no assumptions
about the container runner you choose to use to run the created container.
</para>
<section xml:id="ssec-pkgs-ociTools-buildContainer">
<title>buildContainer</title>
<para>
This function creates a simple OCI container that runs a single command
inside of it. An OCI container consists of a <varname>config.json</varname>
and a rootfs directory.The nix store of the container will contain all
referenced dependencies of the given command.
</para>
<para>
The parameters of <varname>buildContainer</varname> with an example value
are described below:
</para>
<example xml:id='ex-ociTools-buildContainer'>
<title>Build Container</title>
<programlisting>
buildContainer {
cmd = with pkgs; writeScript "run.sh" ''
#!${bash}/bin/bash
${coreutils}/bin/exec ${bash}/bin/bash
''; <co xml:id='ex-ociTools-buildContainer-1' />
mounts = {
"/data" = {
type = "none";
source = "/var/lib/mydata";
options = [ "bind" ];
};
};<co xml:id='ex-ociTools-buildContainer-2' />
readonly = false; <co xml:id='ex-ociTools-buildContainer-3' />
}
</programlisting>
<calloutlist>
<callout arearefs='ex-ociTools-buildContainer-1'>
<para>
<varname>cmd</varname> specifies the program to run inside the container.
This is the only required argument for <varname>buildContainer</varname>.
All referenced packages inside the derivation will be made available
inside the container
</para>
</callout>
<callout arearefs='ex-ociTools-buildContainer-2'>
<para>
<varname>mounts</varname> specifies additional mount points chosen by the
user. By default only a minimal set of necessary filesystems are mounted
into the container (e.g procfs, cgroupfs)
</para>
</callout>
<callout arearefs='ex-ociTools-buildContainer-3'>
<para>
<varname>readonly</varname> makes the container's rootfs read-only if it is set to true.
The default value is false <literal>false</literal>.
</para>
</callout>
</calloutlist>
</example>
</section>
</section>

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{ lib, writeText, runCommand, writeReferencesToFile }:
{
buildContainer =
{ args
, mounts ? {}
, os ? "linux"
, arch ? "x86_64"
, readonly ? false
}:
let
sysMounts = {
"/proc" = {
type = "proc";
source = "proc";
};
"/dev" = {
type = "tmpfs";
source = "tmpfs";
options = [ "nosuid" "strictatime" "mode=755" "size=65536k" ];
};
"/dev/pts" = {
type = "devpts";
source = "devpts";
options = [ "nosuid" "noexec" "newinstance" "ptmxmode=0666" "mode=755" "gid=5" ];
};
"/dev/shm" = {
type = "tmpfs";
source = "shm";
options = [ "nosuid" "noexec" "nodev" "mode=1777" "size=65536k" ];
};
"/dev/mqueue" = {
type = "mqueue";
source = "mqueue";
options = [ "nosuid" "noexec" "nodev" ];
};
"/sys" = {
type = "sysfs";
source = "sysfs";
options = [ "nosuid" "noexec" "nodev" "ro" ];
};
"/sys/fs/cgroup" = {
type = "cgroup";
source = "cgroup";
options = [ "nosuid" "noexec" "nodev" "realatime" "ro" ];
};
};
config = writeText "config.json" (builtins.toJSON {
ociVersion = "1.0.0";
platform = {
inherit os arch;
};
linux = {
namespaces = map (type: { inherit type; }) [ "pid" "network" "mount" "ipc" "uts" ];
};
root = { path = "rootfs"; inherit readonly; };
process = {
inherit args;
user = { uid = 0; gid = 0; };
cwd = "/";
};
mounts = lib.mapAttrsToList (destination: { type, source, options ? null }: {
inherit destination type source options;
}) sysMounts;
});
in
runCommand "join" {} ''
set -o pipefail
mkdir -p $out/rootfs/{dev,proc,sys}
cp ${config} $out/config.json
xargs tar c < ${writeReferencesToFile args} | tar -xC $out/rootfs/
'';
}

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@ -391,6 +391,8 @@ in
nix-gitignore = callPackage ../build-support/nix-gitignore { };
ociTools = callPackage ../build-support/oci-tools { };
pathsFromGraph = ../build-support/kernel/paths-from-graph.pl;
pruneLibtoolFiles = makeSetupHook { name = "prune-libtool-files"; }