TEMP

doc/manual/src/command-ref/nix-channel.md

@@ -43,6 +43,14 @@ This command has the following operations:
 
 Note that `--add` does not automatically perform an update.
 
+It also has the following flags, which affect all operations:
+
+  - `--global`\
+    Operate on the global channels, i.e. the channels shared by all users.
+
+  - `--user`\
+    Operate on the user channels, i.e. the channels just for the current user.
+
 The list of subscribed channels is stored in `~/.nix-channels`.
 
 {{#include ./opt-common.md}}
@@ -86,7 +94,7 @@ $ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
     `${XDG_STATE_HOME-$HOME/.local/state}/nix/profiles/channels`. It ensures that
     `nix-env` can find your channels. In a multi-user installation, you
     may also have `~/.nix-defexpr/channels_root`, which links to the
-    channels of the root user.
+    global channels.
 
 # Channel format
 

doc/manual/src/command-ref/nix-env.md

@@ -9,7 +9,7 @@
   [`--arg` *name* *value*]
   [`--argstr` *name* *value*]
   [{`--file` | `-f`} *path*]
-  [{`--profile` | `-p`} *path*]
+  [{`--profile` | `-p`} *path* | `--global` | `--user`]
   [`--system-filter` *system*]
   [`--dry-run`]
 

doc/manual/src/command-ref/nix-env/opt-common.md

@@ -19,6 +19,16 @@ The following options are allowed for all `nix-env` operations, but may not alwa
     sequence of user environments called *generations*, one of which is
     the *current generation*.
 
+  - `--user`\
+    Specifies the profile as the default profile private to this user.
+    This is a shorthand for passing `--profile` and the path to that
+    default profile. This is default if the current user is not root.
+
+  - `--global`\
+    Specifies the profile as the default global profile shared between all
+    users. A shorthand instead of passing `--profile` and the path to that
+    default profile. This is default if the current user is root.
+
   - `--dry-run`\
     For the `--install`, `--upgrade`, `--uninstall`,
     `--switch-generation`, `--delete-generations` and `--rollback`

src/libcmd/command.cc

@@ -271,7 +271,24 @@ void MixProfile::updateProfile(const BuiltPaths & buildables)
 
 MixDefaultProfile::MixDefaultProfile()
 {
-    profile = getDefaultProfile();
+
+    addFlag({
+        .longName = "user-profile",
+        .description = "Act on the profile for this current user",
+        .handler = {[this]() {
+            profile = getDefaultProfile(DefaultProfileKind::User);
+        }}
+    });
+
+    addFlag({
+        .longName = "global-profile",
+        .description = "Act on the global profile shared between all default users",
+        .handler = {[this]() {
+            profile = getDefaultProfile(DefaultProfileKind::Global);
+        }}
+    });
+
+    profile = getDefaultProfile(defaultDefaultProfileKind());
 }
 
 MixEnvironment::MixEnvironment() : ignoreEnvironment(false)

src/libexpr/eval.cc

@@ -10,6 +10,7 @@
 #include "function-trace.hh"
 #include "profiles.hh"
 #include "print.hh"
+#include "profiles/channels.hh"
 
 #include <algorithm>
 #include <chrono>
@@ -2535,8 +2536,8 @@ Strings EvalSettings::getDefaultNixPath()
 
     if (!evalSettings.restrictEval && !evalSettings.pureEval) {
         add(settings.useXDGBaseDirectories ? getStateDir() + "/nix/defexpr/channels" : getHome() + "/.nix-defexpr/channels");
-        add(rootChannelsDir() + "/nixpkgs", "nixpkgs");
-        add(rootChannelsDir());
+        add(globalChannelsDir() + "/nixpkgs", "nixpkgs");
+        add(globalChannelsDir());
     }
 
     return res;

src/libstore/profiles.cc

@@ -280,50 +280,92 @@ std::string optimisticLockProfile(const Path & profile)
 }
 
 
-Path profilesDir()
+Path userProfilesDir()
 {
-    auto profileRoot =
-        (getuid() == 0)
-        ? rootProfilesDir()
-        : createNixStateDir() + "/profiles";
+    auto profileRoot = createNixStateDir() + "/profiles";
     createDirs(profileRoot);
     return profileRoot;
 }
 
-Path rootProfilesDir()
+/**
+ * Return the path to the global profile directory (but don't try creating it)
+ *
+ * Just used for the global profile and the global channels, but those
+ * go in different subdirs, so we do not expose this.
+ */
+static Path globalProfilesDir()
 {
-    return settings.nixStateDir + "/profiles/per-user/root";
+    return settings.nixStateDir + "/profiles";
 }
 
+/**
+ * The other directory used for global profiles
+ */
+static Path perUsersRootDir()
+{
+    return globalProfilesDir() + "/per-user/root/";
+}
+
+std::vector<Path> globalProfilesDirs()
+{
+    return {
+        globalProfilesDir(),
+        perUsersRootDir(),
+    };
+}
+
+Path getDefaultUserProfile()
+{
+    return userProfilesDir() + "/profile";
+}
 
-Path getDefaultProfile()
+Path getDefaultGlobalProfile()
+{
+    return globalProfilesDir() + "/default";
+}
+
+DefaultProfileKind defaultDefaultProfileKind()
+{
+    return getuid() == 0
+        ? DefaultProfileKind::Global
+        : DefaultProfileKind::User;
+}
+
+Path getDefaultProfile(DefaultProfileKind profileKind)
 {
     Path profileLink = settings.useXDGBaseDirectories ? createNixStateDir() + "/profile" : getHome() + "/.nix-profile";
     try {
-        auto profile = profilesDir() + "/profile";
+        Path profile = "";
+        switch (profileKind) {
+            case DefaultProfileKind::Global:
+                profile = getDefaultGlobalProfile();
+                break;
+            case DefaultProfileKind::User:
+                profile = getDefaultUserProfile();
+                break;
+            default:
+                assert(false);
+        }
         if (!pathExists(profileLink)) {
             replaceSymlink(profile, profileLink);
         }
-        // Backwards compatibiliy measure: Make root's profile available as
-        // `.../default` as it's what NixOS and most of the init scripts expect
-        Path globalProfileLink = settings.nixStateDir + "/profiles/default";
-        if (getuid() == 0 && !pathExists(globalProfileLink)) {
-            replaceSymlink(profile, globalProfileLink);
-        }
         return absPath(readLink(profileLink), dirOf(profileLink));
     } catch (Error &) {
         return profileLink;
     }
 }
 
-Path defaultChannelsDir()
+Path userChannelsDir()
 {
-    return profilesDir() + "/channels";
+    return userProfilesDir() + "/channels";
 }
 
-Path rootChannelsDir()
+Path globalChannelsDir()
 {
-    return rootProfilesDir() + "/channels";
+    /* "per-user" might seem like a weird thing to include in the path
+       to the "global" channels dir; it is done this way for
+       back-compat. */
+    return perUsersRootDir() + "/channels";
 }
 
 }

src/libstore/profiles.hh

@@ -81,28 +81,42 @@ std::string optimisticLockProfile(const Path & profile);
  * Create and return the path to a directory suitable for storing the user’s
  * profiles.
  */
-Path profilesDir();
+Path userProfilesDir();
 
 /**
- * Return the path to the profile directory for root (but don't try creating it)
+ * Create and return the paths to the directories use for storing the
+ * global profiles. There are multiple for backwards compatibility
+ * reasons.
  */
-Path rootProfilesDir();
+std::vector<Path> globalProfilesDirs();
 
 /**
- * Create and return the path to the file used for storing the users's channels
+ * We have two types of default profiles:
+ *
+ * - User, just for the current user (read/write).
+ *
+ * - Global, shared (read-only) by all users.
  */
-Path defaultChannelsDir();
+enum class DefaultProfileKind
+{
+   User,
+   Global,
+};
 
 /**
- * Return the path to the channel directory for root (but don't try creating it)
+ * Returns the default kind of default profile.
+ *
+ * For regular users, this is DefaultProfileKind::Global, but for root it is DefaultProfileKind::User.
  */
-Path rootChannelsDir();
+DefaultProfileKind defaultDefaultProfileKind();
 
 /**
  * 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
+ * and create if doesn't exist.
+ *
+ * @param kind Just used if the profile doesn't exist.
  */
-Path getDefaultProfile();
+Path getDefaultProfile(DefaultProfileKind kind);
 
 }

src/libstore/profiles/channels.hh

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "types.hh"
+
+namespace nix {
+
+/**
+ * Create and return the path to the file used for storing the user's channels
+ */
+Path userChannelsDir();
+
+/**
+ * Return the path to the global channel directory (but don't try creating it)
+ */
+Path globalChannelsDir();
+
+}

src/nix-channel/nix-channel.cc

@@ -1,4 +1,5 @@
 #include "profiles.hh"
+#include "profiles/channels.hh"
 #include "shared.hh"
 #include "globals.hh"
 #include "filetransfer.hh"
@@ -167,10 +168,6 @@ static int main_nix_channel(int argc, char ** argv)
         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";
-        createDirs(dirOf(profile));
-
         enum {
             cNone,
             cAdd,
@@ -179,6 +176,9 @@ static int main_nix_channel(int argc, char ** argv)
             cUpdate,
             cRollback
         } cmd = cNone;
+
+        DefaultProfileKind profileKind = defaultDefaultProfileKind();
+
         std::vector<std::string> args;
         parseCmdLine(argc, argv, [&](Strings::iterator & arg, const Strings::iterator & end) {
             if (*arg == "--help") {
@@ -195,6 +195,10 @@ static int main_nix_channel(int argc, char ** argv)
                 cmd = cUpdate;
             } else if (*arg == "--rollback") {
                 cmd = cRollback;
+            } else if (*arg == "--user") {
+                profileKind = DefaultProfileKind::User;
+            } else if (*arg == "--global") {
+                profileKind = DefaultProfileKind::Global;
             } else {
                 if (hasPrefix(*arg, "-"))
                     throw UsageError("unsupported argument '%s'", *arg);
@@ -203,6 +207,19 @@ static int main_nix_channel(int argc, char ** argv)
             return true;
         });
 
+        // Figure out the name of the channels profile.
+        switch (profileKind) {
+            case DefaultProfileKind::User:
+                profile = userChannelsDir();
+                break;
+            case DefaultProfileKind::Global:
+                profile = globalChannelsDir();
+                break;
+            default:
+                assert(false);
+        };
+        createDirs(dirOf(profile));
+
         switch (cmd) {
             case cNone:
                 throw UsageError("no command specified");

src/nix-collect-garbage/nix-collect-garbage.cc

@@ -77,7 +77,12 @@ static int main_nix_collect_garbage(int argc, char * * argv)
             return true;
         });
 
-        if (removeOld) removeOldGenerations(profilesDir());
+        if (removeOld) {
+            removeOldGenerations(userProfilesDir());
+            if (getuid() == 0)
+                for (auto && dir : globalProfilesDirs())
+                    removeOldGenerations(dir);
+        }
 
         // Run the actual garbage collector.
         if (!dryRun) {