core/pkgs/build-support/fetchdocker/generic-fetcher.nix
2024-06-30 09:16:52 +01:00

106 lines
3.1 KiB
Nix

{
stdenv,
lib,
haskellPackages,
writeText,
gawk,
}:
let
awk = "${gawk}/bin/awk";
dockerCredentialsFile = import ./credentials.nix { inherit lib; };
in
{
fetcher,
name,
registry ? "https://registry-1.docker.io/v2/",
repository ? "library",
imageName,
sha256,
tag ? "",
layerDigest ? "",
}:
# There must be no slashes in the repository or container names since
# we use these to make the output derivation name for the nix store
# path
assert null == lib.findFirst (c: "/" == c) null (lib.stringToCharacters repository);
assert null == lib.findFirst (c: "/" == c) null (lib.stringToCharacters imageName);
# Only allow hocker-config and hocker-layer as fetchers for now
assert (
builtins.elem fetcher [
"hocker-config"
"hocker-layer"
]
);
# If layerDigest is non-empty then it must not have a 'sha256:' prefix!
assert (if layerDigest != "" then !lib.hasPrefix "sha256:" layerDigest else true);
let
layerDigestFlag = lib.optionalString (layerDigest != "") "--layer ${layerDigest}";
in
stdenv.mkDerivation {
inherit name;
builder = writeText "${fetcher}-builder.sh" ''
source "$stdenv/setup"
echo "${fetcher} exporting to $out"
declare -A creds
# This is a hack for Hydra since we have no way of adding values
# to the NIX_PATH for Hydra jobsets!!
staticCredentialsFile="/etc/nix-docker-credentials.txt"
if [ ! -f "$dockerCredentialsFile" -a -f "$staticCredentialsFile" ]; then
echo "credentials file not set, falling back on static credentials file at: $staticCredentialsFile"
dockerCredentialsFile=$staticCredentialsFile
fi
if [ -f "$dockerCredentialsFile" ]; then
echo "using credentials from $dockerCredentialsFile"
CREDSFILE=$(cat "$dockerCredentialsFile")
creds[token]=$(${awk} -F'=' '/DOCKER_TOKEN/ {print $2}' <<< "$CREDSFILE" | head -n1)
# Prefer DOCKER_TOKEN over the username and password
# authentication method
if [ -z "''${creds[token]}" ]; then
creds[user]=$(${awk} -F'=' '/DOCKER_USER/ {print $2}' <<< "$CREDSFILE" | head -n1)
creds[pass]=$(${awk} -F'=' '/DOCKER_PASS/ {print $2}' <<< "$CREDSFILE" | head -n1)
fi
fi
# These variables will be filled in first by the impureEnvVars, if
# those variables are empty then they will default to the
# credentials that may have been read in from the 'DOCKER_CREDENTIALS'
DOCKER_USER="''${DOCKER_USER:-''${creds[user]}}"
DOCKER_PASS="''${DOCKER_PASS:-''${creds[pass]}}"
DOCKER_TOKEN="''${DOCKER_TOKEN:-''${creds[token]}}"
${fetcher} --out="$out" \
''${registry:+--registry "$registry"} \
''${DOCKER_USER:+--username "$DOCKER_USER"} \
''${DOCKER_PASS:+--password "$DOCKER_PASS"} \
''${DOCKER_TOKEN:+--token "$DOCKER_TOKEN"} \
${layerDigestFlag} \
"${repository}/${imageName}" \
"${tag}"
'';
buildInputs = [ haskellPackages.hocker ];
outputHashAlgo = "sha256";
outputHashMode = "flat";
outputHash = sha256;
preferLocalBuild = true;
impureEnvVars = [
"DOCKER_USER"
"DOCKER_PASS"
"DOCKER_TOKEN"
];
inherit registry dockerCredentialsFile;
}