A great 2016 blog post described building minimal Docker images with Nix. The below is a simple example taken from that blog post, modified to support Nix 2.0:
{ pkgs ? import <nixpkgs> {} }:
with pkgs;
dockerTools.buildImage {
name = "redis";
runAsRoot = ''
#!${stdenv.shell}
${dockerTools.shadowSetup}
groupadd -r redis
useradd -r -g redis -d /data -M redis
mkdir /data
chown redis:redis /data
'';
config = {
Cmd = [ "${gosu.bin}/bin/gosu" "redis" "${redis}/bin/redis-server" ];
ExposedPorts = {
"6379/tcp" = {};
};
WorkingDir = "/data";
Volumes = {
"/data" = {};
};
};
}
Using nix-linuxkit to have an x86_64-linux builder, this fails with an error about a bash executable which can't be run:
$ nix-build --system x86_64-linux redis-small.nix
these derivations will be built:
/nix/store/iixmgfhsczc71484vcwqwz2nzlg0rcv1-extra-commands.sh.drv
/nix/store/jsydsrzs7h9pfnh8m6cxaysa9bafmp2z-redis-config.json.drv
/nix/store/csfmyw6va3b8dabshliqjkrrdr6n090w-vm-run-stage2.drv
/nix/store/l0p201r6zjfzsznfb6ykca1l8n09lyb9-vm-run.drv
/nix/store/s64kqfyggqm60l5j9wy6s1nz39iwkxiw-run-as-root.sh.drv
/nix/store/zidg0xphc7yjc4n0w3k7wnifz6rlqgzh-docker-layer-redis.drv
/nix/store/12ahsincv8igv492gzjjvw9s8aaff65i-runtime-deps.drv
/nix/store/pyx4q2wln2shlnjdp5ng43aqd6iba80d-docker-image-redis.tar.gz.drv
these paths will be fetched (1.08 MiB download, 6.95 MiB unpacked):
/nix/store/1cyg1n1rj1nm3ar6dpzlscqgrnqsh5z8-redis-4.0.11
/nix/store/lfvghb4aqj9h1ja1k1z0y669jfnb0mvp-gosu-2017-05-09-bin
copying path '/nix/store/lfvghb4aqj9h1ja1k1z0y669jfnb0mvp-gosu-2017-05-09-bin' from 'https://cache.nixos.org'...
copying path '/nix/store/1cyg1n1rj1nm3ar6dpzlscqgrnqsh5z8-redis-4.0.11' from 'https://cache.nixos.org'...
building '/nix/store/iixmgfhsczc71484vcwqwz2nzlg0rcv1-extra-commands.sh.drv'...
building '/nix/store/s64kqfyggqm60l5j9wy6s1nz39iwkxiw-run-as-root.sh.drv'...
building '/nix/store/csfmyw6va3b8dabshliqjkrrdr6n090w-vm-run-stage2.drv'...
/nix/store/6v88ick1cxnn5g91m8qrrqww0lrlr27x-bash-4.4-p23/bin/bash: /nix/store/6v88ick1cxnn5g91m8qrrqww0lrlr27x-bash-4.4-p23/bin/bash: cannot execute binary file
/nix/store/6v88ick1cxnn5g91m8qrrqww0lrlr27x-bash-4.4-p23/bin/bash: /nix/store/6v88ick1cxnn5g91m8qrrqww0lrlr27x-bash-4.4-p23/bin/bash: cannot execute binary file
builder for '/nix/store/iixmgfhsczc71484vcwqwz2nzlg0rcv1-extra-commands.sh.drv' failed with exit code 126
builder for '/nix/store/s64kqfyggqm60l5j9wy6s1nz39iwkxiw-run-as-root.sh.drv' failed with exit code 126
cannot build derivation '/nix/store/zidg0xphc7yjc4n0w3k7wnifz6rlqgzh-docker-layer-redis.drv': 1 dependencies couldn't be built
cannot build derivation '/nix/store/pyx4q2wln2shlnjdp5ng43aqd6iba80d-docker-image-redis.tar.gz.drv': 1 dependencies couldn't be built
error: build of '/nix/store/pyx4q2wln2shlnjdp5ng43aqd6iba80d-docker-image-redis.tar.gz.drv' failed
The key line here is /nix/store/6v88ick1cxnn5g91m8qrrqww0lrlr27x-bash-4.4-p23/bin/bash: cannot execute binary file. Using file to inspect that, it's genuinely a Linux ELF binary.
How can I run this down?
