installer: manage remotes state. (#52)

* installer: manage remotes state.

Remotes removed from nix-flatpak config declaration will be uninstalled
at system activation.

Add the capability to delete unmanged remotes at system activation.

Rename `uninstallUnmanagedPackages` to a more generic `uninstallUnmanaged`.

* nixos: pass config value to options.nix.

Fix a regression with config now being available in
options. config is evaluated to override values
from renamed/deprecated options.

* system: home-manager: add deprecation warning.

Trigger a deprecation warning if uninstallUnmanagedPackages
is set.

modules/home-manager.nix

@@ -1,19 +1,22 @@
 { config, lib, pkgs, ... }@args:
 let
-  cfg = config.services.flatpak;
+  cfg = lib.warnIf (! isNull config.services.flatpak.uninstallUnmanagedPackages)
+    "uninstallUnmanagedPackages is deprecated since nix-flatpak 0.4.0 and will be removed in 1.0.0. Use uninstallUnamanged instead."
+    config.services.flatpak;
   installation = "user";
 in
 {
 
-  options.services.flatpak = (import ./options.nix { inherit lib pkgs; })
-  // {
+  options.services.flatpak = (import ./options.nix { inherit config lib pkgs; })
+    // {
     enable = with lib; mkOption {
       type = types.bool;
       default = args.osConfig.services.flatpak.enable or false;
       description = mkDoc "Whether to enable nix-flatpak declarative flatpak management in home-manager.";
     };
   };
 
+
   config = lib.mkIf config.services.flatpak.enable {
     systemd.user.services."flatpak-managed-install" = {
       Unit = {
@@ -53,5 +56,4 @@ in
 
     xdg.enable = true;
   };
-
 }

modules/installer.nix

@@ -7,26 +7,53 @@ let
   # be handled. Right now it introduces a small issue of the state file derivation
   # not being garbage collected even when this module is removed. You can find
   # more details on this design drawback in PR#23
+  # State is represented by a JSON object with keys `packages`, `overrides` and `remotes`.
+  # Example `flatpak-state.json`:
+  # {
+  #   "packages": ["org.gnome.Epiphany", "org.gnome.Epiphany.Devel"],
+  #   "overrides": {
+  #     "org.gnome.Epiphany": {
+  #       "command": "env MOZ_ENABLE_WAYLAND=1 /run/current-system/sw/bin/epiphany",
+  #       "env": "MOZ_ENABLE_WAYLAND=1"
+  #     }
+  #   },
+  #   "remotes": ["flathub", "gnome-nightly"]
+  # }
   gcroots =
     if (installation == "system")
     then "/nix/var/nix/gcroots/"
     else "\${XDG_STATE_HOME:-$HOME/.local/state}/home-manager/gcroots";
   stateFile = pkgs.writeText "flatpak-state.json" (builtins.toJSON {
     packages = map (builtins.getAttr "appId") cfg.packages;
     overrides = cfg.overrides;
+    remotes = map (builtins.getAttr "name") cfg.remotes;
   });
+
   statePath = "${gcroots}/${stateFile.name}";
 
   updateApplications = cfg.update.onActivation || cfg.update.auto.enable;
 
-  handleUnmanagedPackagesCmd = installation: uninstallUnmanagedPackages:
-    lib.optionalString uninstallUnmanagedPackages ''
+  # This script is used to manage the lifecyle of all flatpaks (remotes, packages)
+  # installed on the system.
+  # handeUnmanagedStateCmd is used to handle the case where the user wants nix-flatpak to manage
+  # the state of the system, and uninstall any packages or remotes that are not declared in its config.
+  handleUnmanagedStateCmd = installation: uninstallUnmanagedState:
+    lib.optionalString uninstallUnmanagedState ''
       # Add all installed Flatpak packages to the old state, so only the managed ones (new state) will be kept
       INSTALLED_PACKAGES=$(${pkgs.flatpak}/bin/flatpak --${installation} list --app --columns=application)
       OLD_STATE=$(${pkgs.jq}/bin/jq -r -n \
         --argjson old "$OLD_STATE" \
         --arg installed_packages "$INSTALLED_PACKAGES" \
         '$old + { "packages" : $installed_packages | split("\n") }')
+
+      # Add all configured remoted to the old state, so that only managed ones will be kept across generations.
+      MANAGED_REMOTES=$(${pkgs.flatpak}/bin/flatpak --${installation} remotes --columns=name)
+
+      OLD_STATE=$(${pkgs.jq}/bin/jq -r -n \
+        --argjson old "$OLD_STATE" \
+        --arg managed_remotes "$MANAGED_REMOTES" \
+        '$old + { "remotes": $managed_remotes | split("\n") }')
+
     '';
 
   flatpakUninstallCmd = installation: {}: ''
@@ -85,37 +112,55 @@ let
     ''}
   '';
 
-  flatpakAddRemoteCmd = installation: { name, location, args ? null, ... }: ''
+  flatpakAddRemotesCmd = installation: { name, location, args ? null, ... }: ''
     ${pkgs.flatpak}/bin/flatpak remote-add --${installation} --if-not-exists ${if args == null then "" else args} ${name} ${location}
   '';
-  flatpakAddRemote = installation: remotes: map (flatpakAddRemoteCmd installation) remotes;
+  flatpakAddRemote = installation: remotes: map (flatpakAddRemotesCmd installation) remotes;
+
+  flatpakDeleteRemotesCmd = installation: {}: ''
+      # Delete all remotes that are present in the old state but not the new one
+      # $OLD_STATE and $NEW_STATE are globals, declared in the output of pkgs.writeShellScript.
+      ${pkgs.jq}/bin/jq -r -n \
+        --argjson old "$OLD_STATE" \
+        --argjson new "$NEW_STATE" \
+         '(($old.remotes // []) - ($new.remotes // []))[]' \
+        | while read -r REMOTE_NAME; do
+            ${pkgs.flatpak}/bin/flatpak remote-delete --${installation} $REMOTE_NAME
+        done
+  '';
+
+
   flatpakInstall = installation: update: packages: map (flatpakInstallCmd installation update) packages;
 
   mkFlatpakInstallCmd = installation: update: packages: builtins.foldl' (x: y: x + y) '''' (flatpakInstall installation update packages);
-  mkFlatpakAddRemoteCmd = installation: remotes: builtins.foldl' (x: y: x + y) '''' (flatpakAddRemote installation remotes);
+  mkFlatpakAddRemotesCmd = installation: remotes: builtins.foldl' (x: y: x + y) '''' (flatpakAddRemote installation remotes);
 in
 pkgs.writeShellScript "flatpak-managed-install" ''
   # This script is triggered at build time by a transient systemd unit.
   set -eu
 
-  # Setup state variables
+  # Setup state variables for packages and remotes
   NEW_STATE=$(${pkgs.coreutils}/bin/cat ${stateFile})
   if [[ -f ${statePath} ]]; then
     OLD_STATE=$(${pkgs.coreutils}/bin/cat ${statePath})
   else
     OLD_STATE={}
   fi
 
-  # Handle unmanaged packages
-  ${handleUnmanagedPackagesCmd installation cfg.uninstallUnmanagedPackages}
+  # Handle unmanaged packages and remotes.
+  ${handleUnmanagedStateCmd installation cfg.uninstallUnmanaged}
 
   # Configure remotes
-  ${mkFlatpakAddRemoteCmd installation cfg.remotes}
+  ${mkFlatpakAddRemotesCmd installation cfg.remotes}
 
   # Uninstall packages that have been removed from services.flatpak.packages
   # since the previous activation.
   ${flatpakUninstallCmd installation {}}
 
+  # Uninstall remotes that have been removed from services.flatpak.packages
+  # since the previous activation.
+  ${flatpakDeleteRemotesCmd installation {}}
+
   # Install packages
   ${mkFlatpakInstallCmd installation updateApplications cfg.packages}
 

modules/nixos.nix

@@ -1,10 +1,12 @@
 { config, lib, pkgs, ... }:
 let
-  cfg = config.services.flatpak;
+  cfg = lib.warnIf (! isNull config.services.flatpak.uninstallUnmanagedPackages)
+    "uninstallUnmanagedPackages is deprecated since nix-flatpak 0.4.0 and will be removed in 1.0.0. Use uninstallUnamanged instead."
+    config.services.flatpak;
   installation = "system";
 in
 {
-  options.services.flatpak = import ./options.nix { inherit lib pkgs; };
+  options.services.flatpak = import ./options.nix { inherit config lib pkgs; };
 
   config = lib.mkIf config.services.flatpak.enable {
     systemd.services."flatpak-managed-install" = {

modules/options.nix

@@ -1,4 +1,4 @@
-{ lib, ... }:
+{ config, lib, ... }:
 with lib;
 let
   remoteOptions = _: {
@@ -124,7 +124,7 @@ in
 
   overrides = mkOption {
     type = with types; attrsOf (attrsOf (attrsOf (either str (listOf str))));
-    default = {};
+    default = { };
     description = lib.mdDoc ''
       Applies the provided attribute set into a Flatpak overrides file with the
       same structure, keeping externally applied changes.
@@ -166,12 +166,19 @@ in
   };
 
   uninstallUnmanagedPackages = mkOption {
+    type = lib.types.nullOr (lib.types.bool);
+    default = null;
+    description = lib.mdDoc ''
+      uninstallUnmanagedPackages is deprecated. Use uninstallUnamanged instead.'';
+  };
+
+  uninstallUnmanaged = mkOption {
     type = with types; bool;
-    default = false;
+    default = config.services.flatpak.uninstallUnmanagedPackages || false;
     description = lib.mdDoc ''
-      If enabled, uninstall packages not managed by this module on activation.
+      If enabled, uninstall packages and delete remotes not managed by this module on activation.
       I.e. if packages were installed via Flatpak directly instead of this module,
-      they would get uninstalled on the next activation.
+      they would get uninstalled on the next activation. The same applies to remotes manually setup via `flatpak remote-add`
     '';
   };
 }

testing-base/flatpak.nix

@@ -10,7 +10,7 @@
   }];
 
   services.flatpak.update.auto.enable = false;
-  services.flatpak.uninstallUnmanagedPackages = true;
+  services.flatpak.uninstallUnmanaged = false;
   services.flatpak.packages = [
     #{ appId = "com.brave.Browser"; origin = "flathub"; }
     #"com.obsproject.Studio"