EGQ4SEV5BPG6C6TMBWGYH3OE7O3XSKNGBBVO23BBVIX6GFUUZLHAC · Changes

file deletion: podman-setup-script.nix (----------)

[2.311]→[2.1923:1970](∅→∅),[2.1970]→[2.694:694](∅→∅)

{ pkgs }:

let

registriesConf = pkgs.writeText "registries.conf" ''

[registries.search]

registries = ['docker.io']

[registries.block]

registries = []

'';

storageConf = pkgs.writeText "storage.conf" ''

[storage]

driver = "overlay"

# rootless_storage_path="$XDG_DATA_HOME/containers/storage"

'';

in pkgs.writeShellScript "podman-setup" ''

# Dont overwrite customised configuration

if ! test -f ~/.config/containers/policy.json; then

echo "Installing missing ~/.config/containers/policy.json"

install -Dm644 ${pkgs.skopeo.src}/default-policy.json ~/.config/containers/policy.json

fi

if ! test -f ~/.config/containers/registries.conf; then

echo "Installing missing ~/.config/containers/registries.conf"

install -Dm644 ${registriesConf} ~/.config/containers/registries.conf

fi

if ! test -f ~/.config/containers/storage.conf; then

echo "Installing missing ~/.config/containers/storage.conf"

install -Dm644 ${storageConf} ~/.config/containers/storage.conf

fi

if ! grep -q "^''${USER}:" /etc/subuid; then

    echo "No subuid range defined for user, consider running 'sudo usermod --add-subuids 10000-75535 ''${USER}' to allow rootless podman to work"

fi

''

edit in 04-cmake-and-cross/wttr-delft.nix at line 1

[2.343]

[2.344]

# This file looks very similar to what official packages in nixpkgs look like

edit in 04-cmake-and-cross/wttr-delft.nix at line 7

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# Our package name

edit in 04-cmake-and-cross/wttr-delft.nix at line 8

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# Where the source code lives

replacement in 04-cmake-and-cross/wttr-delft.nix at line 11

[2.558]→[2.558:597](∅→∅)

nativeBuildInputs = [

cmake

];

[2.558]

[2.597]

# Since we include CMake, Nix will automatically do all the right things:

# We don't need a custom 'buildPhase' or 'installPhase' anymore.

nativeBuildInputs = [ cmake ];

replacement in 04-cmake-and-cross/wttr-delft.nix at line 16

[2.615]→[2.615:651](∅→∅)

buildInputs = [

curl.dev

];

[2.615]

[2.651]

buildInputs = [ curl.dev ];

# Strict separation of

# nativeBuildInputs (needed at build time only) and

# buildInputs (needed at runtime as well)

strictDeps = true;

edit in 04-cmake-and-cross/flake.nix at line 1

[2.1972]→[2.1973:2042](∅→∅)

# This is a Nix flake

# It is written in the Nix expression language

edit in 04-cmake-and-cross/flake.nix at line 4

[2.2104]→[2.2104:2170](∅→∅)

# nixpkgs is the package repository for the Nix package manager

edit in 04-cmake-and-cross/flake.nix at line 5

[2.2183]

# flake-utils is a utility library to work with flakes (duh)

edit in 04-cmake-and-cross/flake.nix at line 11

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# This creates packages for multiple system types

replacement in 04-cmake-and-cross/flake.nix at line 14

[2.2384]→[2.2384:2461](∅→∅)

# In this simple example we choose to build for "x86_64-linux" only

[2.2384]

[2.2461]

# We import nixpkgs for each particular 'system', and inject

# wttr-delft into the package set using an overlay.

edit in 04-cmake-and-cross/flake.nix at line 22

[2.2650]→[2.2650:4346](∅→∅)

];

};

# Docker image containing only wttr-delft

wttr-delft-container = pkgs.dockerTools.buildLayeredImage {

name = "wttr-delft";

tag = "nix";

# created = "now";

contents = [

pkgs.wttr-delft

];

config = {

Cmd = [

"${pkgs.wttr-delft}/bin/wttr-delft"

];

# Needed for curl to work

Env = [

"SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"

];

};

# Development shell for interacting with containers

# Based on https://gist.github.com/adisbladis/187204cb772800489ee3dac4acdd9947

podman-devshell = let

# Provides a script that copies/creates files that are required for rootless podman

podmanSetupScript = import ./podman-setup-script.nix { inherit pkgs; };

# Provides a fake "docker" binary mapping to podman

dockerCompat = pkgs.runCommandNoCC "docker-podman-compat" {} ''

mkdir -p $out/bin

ln -s ${pkgs.podman}/bin/podman $out/bin/docker

'';

in pkgs.mkShell {

name = "podman";

buildInputs = with pkgs; [

podman # Manage pods, containers and images

runc # Container runtime

conmon # Container runtime monitor

skopeo # Interact with container registry

slirp4netns # User-mode networking for unprivileged namespaces

fuse-overlayfs # CoW for images, much faster than default vfs

dockerCompat # Aliases for docker / podman

edit in 04-cmake-and-cross/flake.nix at line 23

[2.4359]→[2.4359:4497](∅→∅)

shellHook = ''

# Install configuration required for rootless podman

${podmanSetupScript}

'';

edit in 04-cmake-and-cross/flake.nix at line 25

[2.4517]→[2.4517:4581](∅→∅)

# These are the flake outputs, i.e. what we can consume

replacement in 04-cmake-and-cross/flake.nix at line 26

[2.4591]→[2.4591:4895](∅→∅)

packages = {

default = pkgs.wttr-delft;

# static = pkgs.pkgsCross.musl64.pkgsStatic.wttr-delft;

container = wttr-delft-container;

};

devShells = {

default = pkgs.wttr-delft;

podman = podman-devshell;

};

[2.4591]

[2.4895]

packages.default = pkgs.wttr-delft;

file addition: demo.sh (---r------)

[2.311]

#!/usr/bin/env bash

# shellcheck disable=SC1010,SC2288

set -Eeuo pipefail

dir="$(dirname "${BASH_SOURCE[0]}")"

source "${dir}/../libdemo/libdemo.sh"

h Adding CMake

n The more we offload to \'classic\' tools, the easier it is to also build without Nix.

, This makes it an easier sell to use in most cases\; other people are not forced to use it.

, Packaging in this way and making use of the sandboxed Nix build process can hepl find missing dependencies etc.

x pygmentize "${dir}/../src/CMakeLists.txt"

n If we add a proper build system like CMake, the Nix part of building a package gets even easier.

x pygmentize "${dir}/wttr-delft.nix"

x nix build "${dir}" -L

# x nix build "${dir}" -L --rebuild

h Checking out the closure

n The \'closure\' is the full set of all the $runtime$ dependencies:

x nix path-info -sSrh ./result

h Cross-compilation

, We can very easily set up cross-compilation.

, We use the \'flake-utils\' library to abstract away some of the complications in the flake:

x pygmentize "${dir}/flake.nix"

, If we take a look at what the flake provides:

x nix flake show "${dir}"

h The previous build was for x86_64-linux by default because that is our current system:

x file ./result/bin/wttr-delft

h But we can easily build for aarch64-linux $e.g. for Raspberry Pi$:

x nix build "${dir}#packages.aarch64-linux.default" -L

x file ./result/bin/wttr-delft

n If you use NixOS it\'s also very simple to set up binfmt to still be able to run the binary!

Add demo for 04

Dependencies

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