nixpkgs/pkgs/build-support/docker/examples.nix
Robert Hensing 5259d66b74 dockerTools: Allow omitting all store paths
Adds includeStorePaths, allowing the omission of the store paths.
You generally want to leave it on, but tooling may disable this
to insert the store paths more efficiently via other means, such
as bind mounting the host store.
2021-05-26 15:11:42 +02:00

544 lines
14 KiB
Nix

# Examples of using the docker tools to build packages.
#
# This file defines several docker images. In order to use an image,
# build its derivation with `nix-build`, and then load the result with
# `docker load`. For example:
#
# $ nix-build '<nixpkgs>' -A dockerTools.examples.redis
# $ docker load < result
{ pkgs, buildImage, buildLayeredImage, fakeNss, pullImage, shadowSetup, buildImageWithNixDb, pkgsCross }:
rec {
# 1. basic example
bash = buildImage {
name = "bash";
tag = "latest";
contents = pkgs.bashInteractive;
};
# 2. service example, layered on another image
redis = buildImage {
name = "redis";
tag = "latest";
# for example's sake, we can layer redis on top of bash or debian
fromImage = bash;
# fromImage = debian;
contents = pkgs.redis;
runAsRoot = ''
mkdir -p /data
'';
config = {
Cmd = [ "/bin/redis-server" ];
WorkingDir = "/data";
Volumes = {
"/data" = {};
};
};
};
# 3. another service example
nginx = let
nginxPort = "80";
nginxConf = pkgs.writeText "nginx.conf" ''
user nobody nobody;
daemon off;
error_log /dev/stdout info;
pid /dev/null;
events {}
http {
access_log /dev/stdout;
server {
listen ${nginxPort};
index index.html;
location / {
root ${nginxWebRoot};
}
}
}
'';
nginxWebRoot = pkgs.writeTextDir "index.html" ''
<html><body><h1>Hello from NGINX</h1></body></html>
'';
in
buildLayeredImage {
name = "nginx-container";
tag = "latest";
contents = [
fakeNss
pkgs.nginx
];
extraCommands = ''
# nginx still tries to read this directory even if error_log
# directive is specifying another file :/
mkdir -p var/log/nginx
mkdir -p var/cache/nginx
'';
config = {
Cmd = [ "nginx" "-c" nginxConf ];
ExposedPorts = {
"${nginxPort}/tcp" = {};
};
};
};
# 4. example of pulling an image. could be used as a base for other images
nixFromDockerHub = pullImage {
imageName = "nixos/nix";
imageDigest = "sha256:85299d86263a3059cf19f419f9d286cc9f06d3c13146a8ebbb21b3437f598357";
sha256 = "07q9y9r7fsd18sy95ybrvclpkhlal12d30ybnf089hq7v1hgxbi7";
finalImageTag = "2.2.1";
finalImageName = "nix";
};
# 5. example of multiple contents, emacs and vi happily coexisting
editors = buildImage {
name = "editors";
contents = [
pkgs.coreutils
pkgs.bash
pkgs.emacs
pkgs.vim
pkgs.nano
];
};
# 6. nix example to play with the container nix store
# docker run -it --rm nix nix-store -qR $(nix-build '<nixpkgs>' -A nix)
nix = buildImageWithNixDb {
name = "nix";
tag = "latest";
contents = [
# nix-store uses cat program to display results as specified by
# the image env variable NIX_PAGER.
pkgs.coreutils
pkgs.nix
pkgs.bash
];
config = {
Env = [
"NIX_PAGER=cat"
# A user is required by nix
# https://github.com/NixOS/nix/blob/9348f9291e5d9e4ba3c4347ea1b235640f54fd79/src/libutil/util.cc#L478
"USER=nobody"
];
};
};
# 7. example of adding something on top of an image pull by our
# dockerTools chain.
onTopOfPulledImage = buildImage {
name = "onTopOfPulledImage";
tag = "latest";
fromImage = nixFromDockerHub;
contents = [ pkgs.hello ];
};
# 8. regression test for erroneous use of eval and string expansion.
# See issue #34779 and PR #40947 for details.
runAsRootExtraCommands = pkgs.dockerTools.buildImage {
name = "runAsRootExtraCommands";
tag = "latest";
contents = [ pkgs.coreutils ];
# The parens here are to create problematic bash to embed and eval. In case
# this is *embedded* into the script (with nix expansion) the initial quotes
# will close the string and the following parens are unexpected
runAsRoot = ''echo "(runAsRoot)" > runAsRoot'';
extraCommands = ''echo "(extraCommand)" > extraCommands'';
};
# 9. Ensure that setting created to now results in a date which
# isn't the epoch + 1
unstableDate = pkgs.dockerTools.buildImage {
name = "unstable-date";
tag = "latest";
contents = [ pkgs.coreutils ];
created = "now";
};
# 10. Create a layered image
layered-image = pkgs.dockerTools.buildLayeredImage {
name = "layered-image";
tag = "latest";
extraCommands = ''echo "(extraCommand)" > extraCommands'';
config.Cmd = [ "${pkgs.hello}/bin/hello" ];
contents = [ pkgs.hello pkgs.bash pkgs.coreutils ];
};
# 11. Create an image on top of a layered image
layered-on-top = pkgs.dockerTools.buildImage {
name = "layered-on-top";
tag = "latest";
fromImage = layered-image;
extraCommands = ''
mkdir ./example-output
chmod 777 ./example-output
'';
config = {
Env = [ "PATH=${pkgs.coreutils}/bin/" ];
WorkingDir = "/example-output";
Cmd = [
"${pkgs.bash}/bin/bash" "-c" "echo hello > foo; cat foo"
];
};
};
# 12 Create a layered image on top of a layered image
layered-on-top-layered = pkgs.dockerTools.buildLayeredImage {
name = "layered-on-top-layered";
tag = "latest";
fromImage = layered-image;
extraCommands = ''
mkdir ./example-output
chmod 777 ./example-output
'';
config = {
Env = [ "PATH=${pkgs.coreutils}/bin/" ];
WorkingDir = "/example-output";
Cmd = [
"${pkgs.bash}/bin/bash" "-c" "echo hello > foo; cat foo"
];
};
};
# 13. example of running something as root on top of a parent image
# Regression test related to PR #52109
runAsRootParentImage = buildImage {
name = "runAsRootParentImage";
tag = "latest";
runAsRoot = "touch /example-file";
fromImage = bash;
};
# 14. example of 3 layers images This image is used to verify the
# order of layers is correct.
# It allows to validate
# - the layer of parent are below
# - the order of parent layer is preserved at image build time
# (this is why there are 3 images)
layersOrder = let
l1 = pkgs.dockerTools.buildImage {
name = "l1";
tag = "latest";
extraCommands = ''
mkdir -p tmp
echo layer1 > tmp/layer1
echo layer1 > tmp/layer2
echo layer1 > tmp/layer3
'';
};
l2 = pkgs.dockerTools.buildImage {
name = "l2";
fromImage = l1;
tag = "latest";
extraCommands = ''
mkdir -p tmp
echo layer2 > tmp/layer2
echo layer2 > tmp/layer3
'';
};
in pkgs.dockerTools.buildImage {
name = "l3";
fromImage = l2;
tag = "latest";
contents = [ pkgs.coreutils ];
extraCommands = ''
mkdir -p tmp
echo layer3 > tmp/layer3
'';
};
# 15. Environment variable inheritance.
# Child image should inherit parents environment variables,
# optionally overriding them.
environmentVariablesParent = pkgs.dockerTools.buildImage {
name = "parent";
tag = "latest";
config = {
Env = [
"FROM_PARENT=true"
"LAST_LAYER=parent"
];
};
};
environmentVariables = pkgs.dockerTools.buildImage {
name = "child";
fromImage = environmentVariablesParent;
tag = "latest";
contents = [ pkgs.coreutils ];
config = {
Env = [
"FROM_CHILD=true"
"LAST_LAYER=child"
];
};
};
environmentVariablesLayered = pkgs.dockerTools.buildLayeredImage {
name = "child";
fromImage = environmentVariablesParent;
tag = "latest";
contents = [ pkgs.coreutils ];
config = {
Env = [
"FROM_CHILD=true"
"LAST_LAYER=child"
];
};
};
# 16. Create another layered image, for comparing layers with image 10.
another-layered-image = pkgs.dockerTools.buildLayeredImage {
name = "another-layered-image";
tag = "latest";
config.Cmd = [ "${pkgs.hello}/bin/hello" ];
};
# 17. Create a layered image with only 2 layers
two-layered-image = pkgs.dockerTools.buildLayeredImage {
name = "two-layered-image";
tag = "latest";
config.Cmd = [ "${pkgs.hello}/bin/hello" ];
contents = [ pkgs.bash pkgs.hello ];
maxLayers = 2;
};
# 18. Create a layered image with more packages than max layers.
# coreutils and hello are part of the same layer
bulk-layer = pkgs.dockerTools.buildLayeredImage {
name = "bulk-layer";
tag = "latest";
contents = with pkgs; [
coreutils hello
];
maxLayers = 2;
};
# 19. Create a layered image with a base image and more packages than max
# layers. coreutils and hello are part of the same layer
layered-bulk-layer = pkgs.dockerTools.buildLayeredImage {
name = "layered-bulk-layer";
tag = "latest";
fromImage = two-layered-image;
contents = with pkgs; [
coreutils hello
];
maxLayers = 4;
};
# 20. Create a "layered" image without nix store layers. This is not
# recommended, but can be useful for base images in rare cases.
no-store-paths = pkgs.dockerTools.buildLayeredImage {
name = "no-store-paths";
tag = "latest";
extraCommands = ''
# This removes sharing of busybox and is not recommended. We do this
# to make the example suitable as a test case with working binaries.
cp -r ${pkgs.pkgsStatic.busybox}/* .
'';
};
nixLayered = pkgs.dockerTools.buildLayeredImageWithNixDb {
name = "nix-layered";
tag = "latest";
contents = [
# nix-store uses cat program to display results as specified by
# the image env variable NIX_PAGER.
pkgs.coreutils
pkgs.nix
pkgs.bash
];
config = {
Env = [
"NIX_PAGER=cat"
# A user is required by nix
# https://github.com/NixOS/nix/blob/9348f9291e5d9e4ba3c4347ea1b235640f54fd79/src/libutil/util.cc#L478
"USER=nobody"
];
};
};
# 21. Support files in the store on buildLayeredImage
# See: https://github.com/NixOS/nixpkgs/pull/91084#issuecomment-653496223
filesInStore = pkgs.dockerTools.buildLayeredImageWithNixDb {
name = "file-in-store";
tag = "latest";
contents = [
pkgs.coreutils
pkgs.nix
(pkgs.writeScriptBin "myscript" ''
#!${pkgs.runtimeShell}
cat ${pkgs.writeText "somefile" "some data"}
'')
];
config = {
Cmd = [ "myscript" ];
# For some reason 'nix-store --verify' requires this environment variable
Env = [ "USER=root" ];
};
};
# 22. Ensure that setting created to now results in a date which
# isn't the epoch + 1 for layered images.
unstableDateLayered = pkgs.dockerTools.buildLayeredImage {
name = "unstable-date-layered";
tag = "latest";
contents = [ pkgs.coreutils ];
created = "now";
};
# buildImage without explicit tag
bashNoTag = pkgs.dockerTools.buildImage {
name = "bash-no-tag";
contents = pkgs.bashInteractive;
};
# buildLayeredImage without explicit tag
bashNoTagLayered = pkgs.dockerTools.buildLayeredImage {
name = "bash-no-tag-layered";
contents = pkgs.bashInteractive;
};
# buildImage without explicit tag
bashNoTagStreamLayered = pkgs.dockerTools.streamLayeredImage {
name = "bash-no-tag-stream-layered";
contents = pkgs.bashInteractive;
};
# buildLayeredImage with non-root user
bashLayeredWithUser =
let
nonRootShadowSetup = { user, uid, gid ? uid }: with pkgs; [
(
writeTextDir "etc/shadow" ''
root:!x:::::::
${user}:!:::::::
''
)
(
writeTextDir "etc/passwd" ''
root:x:0:0::/root:${runtimeShell}
${user}:x:${toString uid}:${toString gid}::/home/${user}:
''
)
(
writeTextDir "etc/group" ''
root:x:0:
${user}:x:${toString gid}:
''
)
(
writeTextDir "etc/gshadow" ''
root:x::
${user}:x::
''
)
];
in
pkgs.dockerTools.buildLayeredImage {
name = "bash-layered-with-user";
tag = "latest";
contents = [ pkgs.bash pkgs.coreutils ] ++ nonRootShadowSetup { uid = 999; user = "somebody"; };
};
# basic example, with cross compilation
cross = let
# Cross compile for x86_64 if on aarch64
crossPkgs =
if pkgs.system == "aarch64-linux" then pkgsCross.gnu64
else pkgsCross.aarch64-multiplatform;
in crossPkgs.dockerTools.buildImage {
name = "hello-cross";
tag = "latest";
contents = crossPkgs.hello;
};
# layered image where a store path is itself a symlink
layeredStoreSymlink =
let
target = pkgs.writeTextDir "dir/target" "Content doesn't matter.";
symlink = pkgs.runCommandNoCC "symlink" {} "ln -s ${target} $out";
in
pkgs.dockerTools.buildLayeredImage {
name = "layeredstoresymlink";
tag = "latest";
contents = [ pkgs.bash symlink ];
} // { passthru = { inherit symlink; }; };
# image with registry/ prefix
prefixedImage = pkgs.dockerTools.buildImage {
name = "registry-1.docker.io/image";
tag = "latest";
config.Cmd = [ "${pkgs.hello}/bin/hello" ];
};
# layered image with registry/ prefix
prefixedLayeredImage = pkgs.dockerTools.buildLayeredImage {
name = "registry-1.docker.io/layered-image";
tag = "latest";
config.Cmd = [ "${pkgs.hello}/bin/hello" ];
};
# layered image with files owned by a user other than root
layeredImageWithFakeRootCommands = pkgs.dockerTools.buildLayeredImage {
name = "layered-image-with-fake-root-commands";
tag = "latest";
contents = [
pkgs.pkgsStatic.busybox
];
fakeRootCommands = ''
mkdir -p ./home/jane
chown 1000 ./home/jane
'';
};
# tarball consisting of both bash and redis images
mergedBashAndRedis = pkgs.dockerTools.mergeImages [
bash
redis
];
# tarball consisting of bash (without tag) and redis images
mergedBashNoTagAndRedis = pkgs.dockerTools.mergeImages [
bashNoTag
redis
];
# tarball consisting of bash and layered image with different owner of the
# /home/jane directory
mergedBashFakeRoot = pkgs.dockerTools.mergeImages [
bash
layeredImageWithFakeRootCommands
];
helloOnRoot = pkgs.dockerTools.streamLayeredImage {
name = "hello";
tag = "latest";
contents = [
(pkgs.buildEnv {
name = "hello-root";
paths = [ pkgs.hello ];
})
];
config.Cmd = [ "hello" ];
};
helloOnRootNoStore = pkgs.dockerTools.streamLayeredImage {
name = "hello";
tag = "latest";
contents = [
(pkgs.buildEnv {
name = "hello-root";
paths = [ pkgs.hello ];
})
];
config.Cmd = [ "hello" ];
includeStorePaths = false;
};
}