lix/tests/fetchGit.sh
Eelco Dolstra d4dcffd643
Add pure evaluation mode
In this mode, the following restrictions apply:

* The builtins currentTime, currentSystem and storePath throw an
  error.

* $NIX_PATH and -I are ignored.

* fetchGit and fetchMercurial require a revision hash.

* fetchurl and fetchTarball require a sha256 attribute.

* No file system access is allowed outside of the paths returned by
  fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is
  not allowed.

Thus, the evaluation result is completely reproducible from the
command line arguments. E.g.

  nix build --pure-eval '(
    let
      nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; };
      nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; };
    in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux
  )'

The goal is to enable completely reproducible and traceable
evaluation. For example, a NixOS configuration could be fully
described by a single Git commit hash. 'nixos-rebuild' would do
something like

  nix build --pure-eval '(
    (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system
  ')

where the Git repository /my-nixos-config would use further fetchGit
calls or Git externals to fetch Nixpkgs and whatever other
dependencies it has. Either way, the commit hash would uniquely
identify the NixOS configuration and allow it to reproduced.
2018-01-16 19:23:18 +01:00

142 lines
4.7 KiB
Bash

source common.sh
if [[ -z $(type -p git) ]]; then
echo "Git not installed; skipping Git tests"
exit 99
fi
clearStore
repo=$TEST_ROOT/git
rm -rf $repo ${repo}-tmp $TEST_HOME/.cache/nix/git
git init $repo
git -C $repo config user.email "foobar@example.com"
git -C $repo config user.name "Foobar"
echo utrecht > $repo/hello
touch $repo/.gitignore
git -C $repo add hello .gitignore
git -C $repo commit -m 'Bla1'
rev1=$(git -C $repo rev-parse HEAD)
echo world > $repo/hello
git -C $repo commit -m 'Bla2' -a
rev2=$(git -C $repo rev-parse HEAD)
# Fetch the default branch.
path=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath")
[[ $(cat $path/hello) = world ]]
# In pure eval mode, fetchGit without a revision should fail.
[[ $(nix eval --raw "(builtins.readFile (fetchGit file://$repo + \"/hello\"))") = world ]]
(! nix eval --pure-eval --raw "(builtins.readFile (fetchGit file://$repo + \"/hello\"))")
# Fetch using an explicit revision hash.
path2=$(nix eval --raw "(builtins.fetchGit { url = file://$repo; rev = \"$rev2\"; }).outPath")
[[ $path = $path2 ]]
# In pure eval mode, fetchGit with a revision should succeed.
[[ $(nix eval --pure-eval --raw "(builtins.readFile (fetchGit { url = file://$repo; rev = \"$rev2\"; } + \"/hello\"))") = world ]]
# Fetch again. This should be cached.
mv $repo ${repo}-tmp
path2=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath")
[[ $path = $path2 ]]
[[ $(nix eval "(builtins.fetchGit file://$repo).revCount") = 2 ]]
[[ $(nix eval --raw "(builtins.fetchGit file://$repo).rev") = $rev2 ]]
# But with TTL 0, it should fail.
(! nix eval --tarball-ttl 0 "(builtins.fetchGit file://$repo)" -vvvvv)
# Fetching with a explicit hash should succeed.
path2=$(nix eval --tarball-ttl 0 --raw "(builtins.fetchGit { url = file://$repo; rev = \"$rev2\"; }).outPath")
[[ $path = $path2 ]]
path2=$(nix eval --tarball-ttl 0 --raw "(builtins.fetchGit { url = file://$repo; rev = \"$rev1\"; }).outPath")
[[ $(cat $path2/hello) = utrecht ]]
mv ${repo}-tmp $repo
# Using a clean working tree should produce the same result.
path2=$(nix eval --raw "(builtins.fetchGit $repo).outPath")
[[ $path = $path2 ]]
# Using an unclean tree should yield the tracked but uncommitted changes.
mkdir $repo/dir1 $repo/dir2
echo foo > $repo/dir1/foo
echo bar > $repo/bar
echo bar > $repo/dir2/bar
git -C $repo add dir1/foo
git -C $repo rm hello
path2=$(nix eval --raw "(builtins.fetchGit $repo).outPath")
[ ! -e $path2/hello ]
[ ! -e $path2/bar ]
[ ! -e $path2/dir2/bar ]
[ ! -e $path2/.git ]
[[ $(cat $path2/dir1/foo) = foo ]]
[[ $(nix eval --raw "(builtins.fetchGit $repo).rev") = 0000000000000000000000000000000000000000 ]]
# ... unless we're using an explicit ref or rev.
path3=$(nix eval --raw "(builtins.fetchGit { url = $repo; ref = \"master\"; }).outPath")
[[ $path = $path3 ]]
path3=$(nix eval --raw "(builtins.fetchGit { url = $repo; rev = \"$rev2\"; }).outPath")
[[ $path = $path3 ]]
# Committing should not affect the store path.
git -C $repo commit -m 'Bla3' -a
path4=$(nix eval --tarball-ttl 0 --raw "(builtins.fetchGit file://$repo).outPath")
[[ $path2 = $path4 ]]
# tarball-ttl should be ignored if we specify a rev
echo delft > $repo/hello
git -C $repo add hello
git -C $repo commit -m 'Bla4'
rev3=$(git -C $repo rev-parse HEAD)
nix eval --tarball-ttl 3600 "(builtins.fetchGit { url = $repo; rev = \"$rev3\"; })" >/dev/null
# Update 'path' to reflect latest master
path=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath")
# Check behavior when non-master branch is used
git -C $repo checkout $rev2 -b dev
echo dev > $repo/hello
# File URI uses 'master' unless specified otherwise
path2=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath")
[[ $path = $path2 ]]
# Using local path with branch other than 'master' should work when clean or dirty
path3=$(nix eval --raw "(builtins.fetchGit $repo).outPath")
# (check dirty-tree handling was used)
[[ $(nix eval --raw "(builtins.fetchGit $repo).rev") = 0000000000000000000000000000000000000000 ]]
# Committing shouldn't change store path, or switch to using 'master'
git -C $repo commit -m 'Bla5' -a
path4=$(nix eval --raw "(builtins.fetchGit $repo).outPath")
[[ $(cat $path4/hello) = dev ]]
[[ $path3 = $path4 ]]
# Confirm same as 'dev' branch
path5=$(nix eval --raw "(builtins.fetchGit { url = $repo; ref = \"dev\"; }).outPath")
[[ $path3 = $path5 ]]
# Nuke the cache
rm -rf $TEST_HOME/.cache/nix/git
# Try again, but without 'git' on PATH
NIX=$(command -v nix)
# This should fail
(! PATH= $NIX eval --raw "(builtins.fetchGit { url = $repo; ref = \"dev\"; }).outPath" )
# Try again, with 'git' available. This should work.
path5=$(nix eval --raw "(builtins.fetchGit { url = $repo; ref = \"dev\"; }).outPath")
[[ $path3 = $path5 ]]