A setting to follow XDG Base Directory standard

XDG Base Directory is a standard for locations for storing various
files. Nix has a few files which seem to fit in the standard, but
currently use a custom location directly in the user's ~, polluting
it:

- ~/.nix-profile
- ~/.nix-defexpr
- ~/.nix-channels

This commit adds a config option (use-xdg-base-directories) to follow
the XDG spec and instead use the following locations:

- $XDG_STATE_HOME/nix/profile
- $XDG_STATE_HOME/nix/defexpr
- $XDG_STATE_HOME/nix/channels

If $XDG_STATE_HOME is not set, it is assumed to be ~/.local/state.

Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
Co-authored-by: Tim Fenney <kodekata@gmail.com>
Co-authored-by: pasqui23 <pasqui23@users.noreply.github.com>
Co-authored-by: Artturin <Artturin@artturin.com>
Co-authored-by: John Ericson <Ericson2314@Yahoo.com>
This commit is contained in:
Alexander Bantyev 2021-11-17 23:35:21 +03:00
parent a31d7d4e5e
commit 2384d36083
No known key found for this signature in database
GPG key ID: E081FF12ADCB4AD5
16 changed files with 153 additions and 20 deletions

View file

@ -91,3 +91,16 @@ Most Nix commands interpret the following environment variables:
variable sets the initial size of the heap in bytes. It defaults to
384 MiB. Setting it to a low value reduces memory consumption, but
will increase runtime due to the overhead of garbage collection.
## XDG Base Directory
New Nix commands conform to the [XDG Base Directory Specification], and use the following environment variables to determine locations of various state and configuration files:
- [`XDG_CONFIG_HOME`]{#env-XDG_CONFIG_HOME} (default `~/.config`)
- [`XDG_STATE_HOME`]{#env-XDG_STATE_HOME} (default `~/.local/state`)
- [`XDG_CACHE_HOME`]{#env-XDG_CACHE_HOME} (default `~/.cache`)
Classic Nix commands can also be made to follow this standard using the [`use-xdg-base-directories`] configuration option.
[XDG Base Directory Specification]: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
[`use-xdg-base-directories`]: ../command-ref/conf-file.md#conf-use-xdg-base-directories

View file

@ -136,7 +136,7 @@ EOF
cat <<EOF
$step. Delete the files Nix added to your system:
sudo rm -rf /etc/nix $NIX_ROOT $ROOT_HOME/.nix-profile $ROOT_HOME/.nix-defexpr $ROOT_HOME/.nix-channels $HOME/.nix-profile $HOME/.nix-defexpr $HOME/.nix-channels
sudo rm -rf "/etc/nix" "$NIX_ROOT" "$ROOT_HOME/.nix-profile" "$ROOT_HOME/.nix-defexpr" "$ROOT_HOME/.nix-channels" "$ROOT_HOME/.local/state/nix" "$ROOT_HOME/.cache/nix" "$HOME/.nix-profile" "$HOME/.nix-defexpr" "$HOME/.nix-channels" "$HOME/.local/state/nix" "$HOME/.cache/nix"
and that is it.

View file

@ -188,6 +188,8 @@ fi
# shellcheck source=./nix-profile.sh.in
. "$nix/etc/profile.d/nix.sh"
NIX_LINK="$HOME/.nix-profile"
if ! "$nix/bin/nix-env" -i "$nix"; then
echo "$0: unable to install Nix into your default profile" >&2
exit 1
@ -196,7 +198,7 @@ fi
# Install an SSL certificate bundle.
if [ -z "$NIX_SSL_CERT_FILE" ] || ! [ -f "$NIX_SSL_CERT_FILE" ]; then
"$nix/bin/nix-env" -i "$cacert"
export NIX_SSL_CERT_FILE="$HOME/.nix-profile/etc/ssl/certs/ca-bundle.crt"
export NIX_SSL_CERT_FILE="$NIX_LINK/etc/ssl/certs/ca-bundle.crt"
fi
# Subscribe the user to the Nixpkgs channel and fetch it.
@ -214,8 +216,8 @@ fi
added=
p=
p_sh=$HOME/.nix-profile/etc/profile.d/nix.sh
p_fish=$HOME/.nix-profile/etc/profile.d/nix.fish
p_sh=$NIX_LINK/etc/profile.d/nix.sh
p_fish=$NIX_LINK/etc/profile.d/nix.fish
if [ -z "$NIX_INSTALLER_NO_MODIFY_PROFILE" ]; then
# Make the shell source nix.sh during login.
for i in .bash_profile .bash_login .profile; do

View file

@ -2,7 +2,33 @@
if [ -n "${__ETC_PROFILE_NIX_SOURCED:-}" ]; then return; fi
__ETC_PROFILE_NIX_SOURCED=1
export NIX_PROFILES="@localstatedir@/nix/profiles/default $HOME/.nix-profile"
NIX_LINK=$HOME/.nix-profile
if [ -n "$XDG_STATE_HOME" ]; then
NIX_LINK_NEW="$XDG_STATE_HOME/nix/profile"
else
NIX_LINK_NEW=$HOME/.local/state/nix/profile
fi
if ! [ -e "$NIX_LINK" ]; then
NIX_LINK="$NIX_LINK_NEW"
else
if [ -t 2 ] && [ -e "$NIX_LINK_NEW" ]; then
warning="\033[1;35mwarning:\033[0m"
printf "$warning Both %s and legacy %s exist; using the latter.\n" "$NIX_LINK_NEW" "$NIX_LINK" 1>&2
if [ "$(realpath "$NIX_LINK")" = "$(realpath "$NIX_LINK_NEW")" ]; then
printf " Since the profiles match, you can safely delete either of them.\n" 1>&2
else
# This should be an exceptionally rare occasion: the only way to get it would be to
# 1. Update to newer Nix;
# 2. Remove .nix-profile;
# 3. Set the $NIX_LINK_NEW to something other than the default user profile;
# 4. Roll back to older Nix.
# If someone did all that, they can probably figure out how to migrate the profile.
printf "$warning Profiles do not match. You should manually migrate from %s to %s.\n" "$NIX_LINK" "$NIX_LINK_NEW" 1>&2
fi
fi
fi
export NIX_PROFILES="@localstatedir@/nix/profiles/default $NIX_LINK"
# Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
if [ -n "${NIX_SSL_CERT_FILE:-}" ]; then
@ -34,4 +60,5 @@ else
unset -f check_nix_profiles
fi
export PATH="$HOME/.nix-profile/bin:@localstatedir@/nix/profiles/default/bin:$PATH"
export PATH="$NIX_LINK/bin:@localstatedir@/nix/profiles/default/bin:$PATH"
unset NIX_LINK

View file

@ -2,11 +2,35 @@ if [ -n "$HOME" ] && [ -n "$USER" ]; then
# Set up the per-user profile.
NIX_LINK=$HOME/.nix-profile
NIX_LINK="$HOME/.nix-profile"
if [ -n "$XDG_STATE_HOME" ]; then
NIX_LINK_NEW="$XDG_STATE_HOME/nix/profile"
else
NIX_LINK_NEW="$HOME/.local/state/nix/profile"
fi
if ! [ -e "$NIX_LINK" ]; then
NIX_LINK="$NIX_LINK_NEW"
else
if [ -t 2 ] && [ -e "$NIX_LINK_NEW" ]; then
warning="\033[1;35mwarning:\033[0m"
printf "$warning Both %s and legacy %s exist; using the latter.\n" "$NIX_LINK_NEW" "$NIX_LINK" 1>&2
if [ "$(realpath "$NIX_LINK")" = "$(realpath "$NIX_LINK_NEW")" ]; then
printf " Since the profiles match, you can safely delete either of them.\n" 1>&2
else
# This should be an exceptionally rare occasion: the only way to get it would be to
# 1. Update to newer Nix;
# 2. Remove .nix-profile;
# 3. Set the $NIX_LINK_NEW to something other than the default user profile;
# 4. Roll back to older Nix.
# If someone did all that, they can probably figure out how to migrate the profile.
printf "$warning Profiles do not match. You should manually migrate from %s to %s.\n" "$NIX_LINK" "$NIX_LINK_NEW" 1>&2
fi
fi
fi
# Set up environment.
# This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
export NIX_PROFILES="@localstatedir@/nix/profiles/default $HOME/.nix-profile"
export NIX_PROFILES="@localstatedir@/nix/profiles/default $NIX_LINK"
# Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
if [ -e /etc/ssl/certs/ca-certificates.crt ]; then # NixOS, Ubuntu, Debian, Gentoo, Arch
@ -31,5 +55,5 @@ if [ -n "$HOME" ] && [ -n "$USER" ]; then
fi
export PATH="$NIX_LINK/bin:$PATH"
unset NIX_LINK
unset NIX_LINK NIX_LINK_NEW
fi

View file

@ -2496,7 +2496,7 @@ Strings EvalSettings::getDefaultNixPath()
res.push_back(s ? *s + "=" + p : p);
};
add(getHome() + "/.nix-defexpr/channels");
add(settings.useXDGBaseDirectories ? getStateDir() + "/nix/defexpr/channels" : getHome() + "/.nix-defexpr/channels");
add(settings.nixStateDir + "/profiles/per-user/root/channels/nixpkgs", "nixpkgs");
add(settings.nixStateDir + "/profiles/per-user/root/channels");

View file

@ -975,6 +975,27 @@ public:
resolves to a different location from that of the build machine. You
can enable this setting if you are sure you're not going to do that.
)"};
Setting<bool> useXDGBaseDirectories{
this, false, "use-xdg-base-directories",
R"(
If set to `true`, Nix will conform to the [XDG Base Directory Specification] for files in `$HOME`.
The environment variables used to implement this are documented in the [Environment Variables section](@docroot@/installation/env-variables.md).
[XDG Base Directory Specification]: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
> **Warning**
> This changes the location of some well-known symlinks that Nix creates, which might break tools that rely on the old, non-XDG-conformant locations.
In particular, the following locations change:
| Old | New |
|-------------------|--------------------------------|
| `~/.nix-profile` | `$XDG_STATE_HOME/nix/profile` |
| `~/.nix-defexpr` | `$XDG_STATE_HOME/nix/defexpr` |
| `~/.nix-channels` | `$XDG_STATE_HOME/nix/channels` |
)"
};
};

View file

@ -282,7 +282,7 @@ std::string optimisticLockProfile(const Path & profile)
Path profilesDir()
{
auto profileRoot = getDataDir() + "/nix/profiles";
auto profileRoot = createNixStateDir() + "/profiles";
createDirs(profileRoot);
return profileRoot;
}
@ -290,7 +290,7 @@ Path profilesDir()
Path getDefaultProfile()
{
Path profileLink = getHome() + "/.nix-profile";
Path profileLink = settings.useXDGBaseDirectories ? createNixStateDir() + "/profile" : getHome() + "/.nix-profile";
try {
auto profile =
getuid() == 0

View file

@ -72,8 +72,9 @@ std::string optimisticLockProfile(const Path & profile);
profiles. */
Path profilesDir();
/* Resolve ~/.nix-profile. If ~/.nix-profile doesn't exist yet, create
it. */
/* Resolve the default profile (~/.nix-profile by default, $XDG_STATE_HOME/
nix/profile if XDG Base Directory Support is enabled), and create if doesn't
exist */
Path getDefaultProfile();
}

View file

@ -608,6 +608,19 @@ Path getDataDir()
return dataDir ? *dataDir : getHome() + "/.local/share";
}
Path getStateDir()
{
auto stateDir = getEnv("XDG_STATE_HOME");
return stateDir ? *stateDir : getHome() + "/.local/state";
}
Path createNixStateDir()
{
Path dir = getStateDir() + "/nix";
createDirs(dir);
return dir;
}
std::optional<Path> getSelfExe()
{

View file

@ -158,6 +158,12 @@ Path getDataDir();
/* Return the path of the current executable. */
std::optional<Path> getSelfExe();
/* Return $XDG_STATE_HOME or $HOME/.local/state. */
Path getStateDir();
/* Create the Nix state directory and return the path to it. */
Path createNixStateDir();
/* Create a directory and all its parents, if necessary. Returns the
list of created directories, in order of creation. */
Paths createDirs(const Path & path);

View file

@ -164,8 +164,8 @@ static int main_nix_channel(int argc, char ** argv)
{
// Figure out the name of the `.nix-channels' file to use
auto home = getHome();
channelsList = home + "/.nix-channels";
nixDefExpr = home + "/.nix-defexpr";
channelsList = settings.useXDGBaseDirectories ? createNixStateDir() + "/channels" : home + "/.nix-channels";
nixDefExpr = settings.useXDGBaseDirectories ? createNixStateDir() + "/defexpr" : home + "/.nix-defexpr";
// Figure out the name of the channels profile.
profile = profilesDir() + "/channels";

View file

@ -1289,7 +1289,7 @@ static void opSwitchProfile(Globals & globals, Strings opFlags, Strings opArgs)
throw UsageError("exactly one argument expected");
Path profile = absPath(opArgs.front());
Path profileLink = getHome() + "/.nix-profile";
Path profileLink = settings.useXDGBaseDirectories ? createNixStateDir() + "/profile" : getHome() + "/.nix-profile";
switchLink(profileLink, profile);
}
@ -1393,7 +1393,10 @@ static int main_nix_env(int argc, char * * argv)
Globals globals;
globals.instSource.type = srcUnknown;
globals.instSource.nixExprPath = getHome() + "/.nix-defexpr";
{
Path nixExprPath = settings.useXDGBaseDirectories ? createNixStateDir() + "/defexpr" : getHome() + "/.nix-defexpr";
globals.instSource.nixExprPath = nixExprPath;
}
globals.instSource.systemFilter = "*";
if (!pathExists(globals.instSource.nixExprPath)) {

View file

@ -27,6 +27,8 @@ export NIX_REMOTE=$NIX_REMOTE_
unset NIX_PATH
export TEST_HOME=$TEST_ROOT/test-home
export HOME=$TEST_HOME
unset XDG_STATE_HOME
unset XDG_DATA_HOME
unset XDG_CONFIG_HOME
unset XDG_CONFIG_DIRS
unset XDG_CACHE_HOME
@ -62,8 +64,8 @@ readLink() {
}
clearProfiles() {
profiles="$HOME"/.local/share/nix/profiles
rm -rf $profiles
profiles="$HOME"/.local/state/nix/profiles
rm -rf "$profiles"
}
clearStore() {

View file

@ -12,6 +12,19 @@ nix-channel --remove xyzzy
[ -e $TEST_HOME/.nix-channels ]
[ "$(cat $TEST_HOME/.nix-channels)" = '' ]
# Test the XDG Base Directories support
export NIX_CONFIG="use-xdg-base-directories = true"
nix-channel --add http://foo/bar xyzzy
nix-channel --list | grep -q http://foo/bar
nix-channel --remove xyzzy
unset NIX_CONFIG
[ -e $TEST_HOME/.local/state/nix/channels ]
[ "$(cat $TEST_HOME/.local/state/nix/channels)" = '' ]
# Create a channel.
rm -rf $TEST_ROOT/foo
mkdir -p $TEST_ROOT/foo

View file

@ -56,6 +56,14 @@ nix profile history
nix profile history | grep "packages.$system.default: ∅ -> 1.0"
nix profile diff-closures | grep 'env-manifest.nix: ε → ∅'
# Test XDG Base Directories support
export NIX_CONFIG="use-xdg-base-directories = true"
nix profile remove 1
nix profile install $flake1Dir
[[ $($TEST_HOME/.local/state/nix/profile/bin/hello) = "Hello World" ]]
unset NIX_CONFIG
# Test upgrading a package.
printf NixOS > $flake1Dir/who
printf 2.0 > $flake1Dir/version