nixpkgs/pkgs/build-support/fetchdocker/credentials.nix
Parnell Springmeyer 25865688a7
docker: init fetchdocker nix code for docker2nix
This change adds granular, non-docker daemon docker image fetchers and
a docker image layer compositor to be used in conjunction with the
`docker2nix` utility provided by the `haskellPackages.hocker` package.

This change includes a hackage package version bump and updated sha256
for recent fixes released to `hocker` resulting from formulating this
patch.
2017-12-01 21:00:52 -06:00

38 lines
1.5 KiB
Nix

# We provide three paths to get the credentials into the builder's
# environment:
#
# 1. Via impureEnvVars. This method is difficult for multi-user Nix
# installations (but works very well for single-user Nix
# installations!) because it requires setting the environment
# variables on the nix-daemon which is either complicated or unsafe
# (i.e: configuring via Nix means the secrets will be persisted
# into the store)
#
# 2. If the DOCKER_CREDENTIALS key with a path to a credentials file
# is added to the NIX_PATH (usually via the '-I ' argument to most
# Nix tools) then an attempt will be made to read credentials from
# it. The semantics are simple, the file should contain two lines
# for the username and password based authentication:
#
# $ cat ./credentials-file.txt
# DOCKER_USER=myusername
# DOCKER_PASS=mypassword
#
# ... and a single line for the token based authentication:
#
# $ cat ./credentials-file.txt
# DOCKER_TOKEN=mytoken
#
# 3. A credential file at /etc/nix-docker-credentials.txt with the
# same format as the file described in #2 can also be used to
# communicate credentials to the builder. This is necessary for
# situations (like Hydra) where you cannot customize the NIX_PATH
# given to the nix-build invocation to provide it with the
# DOCKER_CREDENTIALS path
let
pathParts =
(builtins.filter
({path, prefix}: "DOCKER_CREDENTIALS" == prefix)
builtins.nixPath);
in
if (pathParts != []) then (builtins.head pathParts).path else ""