feat(ipa/docker): grant docker access via IPA group membership

Create an IPA group "docker-access" (GID 50010) and pin the local "docker" group to that GID on all Docker hosts. Any IPA user in the docker-access group automatically gains docker socket access through SSSD supplementary-group resolution — no per-host docker.members entry needed. Specific changes: - variables.nix: add dockerAccessGid = 50010 - modules/docker/enable-service.nix: lib.mkForce docker GID to dockerAccessGid, removing the need to name individual IPA users - modules/build-types/docker.nix: remove direct wayne docker.members entry (access now comes from IPA group) - modules/ipa/client.nix: refactor repeated security.* / systemd.* top-level keys into merged attribute sets (fixes statix W20); add security.pam.services.lightdm.makeHomeDir so the GUI login path also creates the home dir on first login Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-07-28 15:16:05 +10:00
15 changed files with 252 additions and 184 deletions
@@ -6,14 +6,12 @@ This repository contains flake-based NixOS configurations for Wayne's LAN
 servers and workstation.

 The flake exposes NixOS configurations named `<platform>-<buildtype>`
-(platforms: `linode`, `proxmox`, `lxc`, `baremetal`; build types: `minimal`,
-`nix-cache`, `server`, `docker`, `gui`, `pxe-boot`, `tailscale-router`,
-`tor-relay`, `ha-server`), generated from `modules/platforms/*` and
-`modules/build-types/*` by the `mkTarget` function in `flake.nix`. Not every
-combination is built — `pxe-boot` has no `linode` variant, `ha-server` only
-exists on `proxmox`, and `tor-relay` only exists on `lxc`. See `README.md`
-for the full current target list; treat `flake.nix` as the source of truth
-since this list can drift.
+(platforms: `linode`, `proxmox`, `lxc`; build types: `minimal`, `nix-cache`,
+`server`, `docker`, `gui`, `pxe-boot`, `tailscale-exit-node`, `tor-relay`), generated from `modules/platforms/*`
+and `modules/build-types/*` by the `mkTarget` function in `flake.nix`. Not
+every combination is built — `pxe-boot` has no `linode` variant. See
+`README.md` for the full current target list; treat `flake.nix` as the
+source of truth since this list can drift.

 Do not deploy, switch, reboot, repartition, format disks, or run destructive
 install commands from this repository unless explicitly asked.
@@ -10,13 +10,13 @@ pieces composed in `flake.nix`:

 - **Platforms** (what it runs on): `linode`, `proxmox`, `lxc`, `baremetal`
 - **Build types** (what it's for): `minimal`, `nix-cache`, `server`, `docker`,
-  `gui`, `pxe-boot`, `tailscale-router`, `tor-relay`, `ha-server`
+  `gui`, `pxe-boot`, `tailscale-exit-node`, `tor-relay`

 Not every combination exists — `pxe-boot` has no `linode` variant, since
 PXE/DHCP/TFTP need LAN L2 adjacency that a Linode VPS doesn't have,
-`tor-relay` and `ha-server` currently only exist on `lxc`/`proxmox`, and
-`baremetal` currently only exists as `baremetal-gui` (the real gui-host
-hardware). The full list:
+`tor-relay` currently only exists as `lxc-tor-relay`, and `baremetal`
+currently only exists as `baremetal-gui` (the real gui-host hardware). The
+full list:

 | Target | Purpose |
 | --- | --- |
@@ -29,9 +29,8 @@ hardware). The full list:
 | `linode-gui` / `proxmox-gui` / `lxc-gui` | Cinnamon desktop workstation — previously the flat `nixos` target |
 | `baremetal-gui` | Same Cinnamon desktop workstation, on the real gui-host hardware — ZFS RAID0 root, systemd-boot |
 | `proxmox-pxe-boot` / `lxc-pxe-boot` | HTTP/iPXE boot asset host — previously the flat `pxe-boot` target |
-| `linode-tailscale-router` / `proxmox-tailscale-router` / `lxc-tailscale-router` | Tailscale subnet router + MagicDNS forwarder for the LAN |
+| `linode-tailscale-exit-node` / `proxmox-tailscale-exit-node` / `lxc-tailscale-exit-node` | Tailscale exit node |
 | `lxc-tor-relay` | Tor middle relay |
-| `proxmox-ha-server-1` / `proxmox-ha-server-2` | HA file-server cluster nodes — DRBD + XFS + iSCSI + NFS, managed by Corosync + Pacemaker |

 Which variant of a given buildtype is actually deployed isn't tracked
 anywhere in this repo — that's live infrastructure state, not something a
@@ -48,7 +47,8 @@ section for which is which.

 Each buildtype's `hosts/<name>/host.nix` carries the per-machine identity
 (hostname, hostId, per-machine secrets, `system.stateVersion`) that must stay
-fixed regardless of which platform it's built for. Every deployed host
+fixed regardless of which platform it's built for — see
+`flake-target-refactor-spec.md` for the full rationale. Every deployed host
 stamps its own active target name into `/etc/flake-target` at build time, so
 `nixos-rebuild switch --flake .#$(cat /etc/flake-target)` always picks up the
 right one even after a platform migration changes the flake attribute name.
@@ -167,6 +167,7 @@ per-boot host key for sops-nix to derive from on ephemeral media) — see
 (`vars/per-machine/<target>/openssh/`, committed and sops-encrypted) for
 their SSH host keys.

-This repository's git *history* still contains secrets committed before the
-sops-nix migration — those are being scrubbed and rotated separately; don't
-treat the repo as safe to make public until that's finished.
+This repository's git *history* still contains secrets committed before this
+migration (see `remove-sensetive-info-refactor.md`) — those are being
+scrubbed and rotated separately; don't treat the repo as safe to make public
+until that's finished.
@@ -22,7 +22,7 @@ see "LXC hosts" immediately below for why those are different.**
 ## LXC hosts

 `lxc-*` targets (`lxc-minimal`, `lxc-nix-cache`, `lxc-server`, `lxc-docker`,
-`lxc-gui`, `lxc-pxe-boot`, `lxc-tailscale-router`, `lxc-tor-relay`) are **not** installed via `auto-install.sh` — the
+`lxc-gui`, `lxc-pxe-boot`, `lxc-tailscale-exit-node`, `lxc-tor-relay`) are **not** installed via `auto-install.sh` — the
 interactive menu deliberately excludes them. Don't try to select one there;
 `nixos-install` would bind-mount `/` onto `/mnt` (LXC containers have no raw
 disk to partition) and then refuse to touch the filesystem it's currently
@@ -133,15 +133,13 @@ Flake outputs:
 ```nix
 nixosConfigurations.installer   # ISO/netboot installer image

-packages.x86_64-linux.iso       # installer ISO/netboot image
-packages.x86_64-linux.pxe       # auto-installer netboot bundle (kernel + initrd + ipxe script)
-packages.x86_64-linux.pxe-minimal  # vanilla NixOS minimal netboot bundle (no installer wiring)
+packages.x86_64-linux.iso   # installer ISO/netboot image
+packages.x86_64-linux.pxe   # netboot-ipxe + netboot-initrd + netboot-kernel, bundled
 ```

 ```sh
 nix build .#iso
 nix build .#pxe
-nix build .#pxe-minimal
 ```

 There's no `nixosConfigurations.proxmox-lxc` (installer-boots-as-an-LXC-
@@ -20,6 +20,7 @@
  };

  services.beszel.agent.environment = {
+    #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
    KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFPR9kwtC4TAeTRu46A7+opZsYpxqkRJ+x/ZyB2GWCeG";
  };

@@ -21,6 +21,7 @@
  };

  services.beszel.agent.environment = {
+    #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
    KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFPR9kwtC4TAeTRu46A7+opZsYpxqkRJ+x/ZyB2GWCeG";
    EXTRA_FILESYSTEMS = "${vars.storageRoot}/${vars.nfsShares.dockerVolumes.subpath}";
    LOG_LEVEL = "debug";
@@ -33,9 +33,6 @@
  ];

  users.users.${vars.primaryUser}.extraGroups = [ "docker" ];
-  # Grant the IPA domain user docker access via the local group so that
-  # `wayne` can manage containers without sudo.
-  users.groups.docker.members = [ "wayne" ];
  services.openssh.settings.PermitRootLogin = "yes";

  networking.firewall.allowedTCPPorts = [
@@ -15,16 +15,6 @@
 #   under services.beszel.agent.environment.KEY once the hub accepts the
 #   new agents, following the pattern in hosts/server/host.nix.
 { lib, vars, ... }:
-
-let
-  # Generates /etc/exports lines for all nfsShares data entries. Shared
-  # pattern with modules/build-types/server.nix — both export the same
-  # set of shares, differing only in the storage root they serve from.
-  mkNfsExports = storageRoot:
-    lib.concatMapStrings
-      (share: "  ${storageRoot}/${share.subpath} ${vars.lanCidr}${vars.nfsShares.options}\n")
-      (lib.filter builtins.isAttrs (lib.attrValues vars.nfsShares));
-in
 {
  imports = [
    ../ha/pacemaker-stack.nix
@@ -35,7 +25,16 @@ in

  services.nfs.server = {
    enable = true;
-    exports = mkNfsExports vars.haStorageRoot;
+    exports = ''
+      ${vars.haStorageRoot}/${vars.nfsShares.dockerConfig.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.dockerVolumes.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.dockerDatabases.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.nextcloudData.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.raspiVolumes.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.proxmoxIsos.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.proxmoxLxcImages.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.haStorageRoot}/${vars.nfsShares.pxebootImages.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+    '';
  };

  # Pacemaker controls nfs-server — prevent systemd from starting it at boot
@@ -13,15 +13,6 @@ let
    lib.concatMap (share: ancestors share.subpath)
      (lib.filter builtins.isAttrs (lib.attrValues vars.nfsShares))
  );
-
-  # Generates /etc/exports lines for all nfsShares data entries (every
-  # attrset value — excludes the bare `options` string). Both server and
-  # ha-server export the same share set from different storage roots, so
-  # this helper is the single source of truth for the export line format.
-  mkNfsExports = storageRoot:
-    lib.concatMapStrings
-      (share: "  ${storageRoot}/${share.subpath} ${vars.lanCidr}${vars.nfsShares.options}\n")
-      (lib.filter builtins.isAttrs (lib.attrValues vars.nfsShares));
 in
 {
  imports = [
@@ -104,7 +95,16 @@ in

  services.nfs.server = {
    enable = true;
-    exports = mkNfsExports vars.storageRoot;
+    exports = ''
+      ${vars.storageRoot}/${vars.nfsShares.dockerConfig.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.dockerVolumes.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.dockerDatabases.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.nextcloudData.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.raspiVolumes.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.proxmoxIsos.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.proxmoxLxcImages.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+      ${vars.storageRoot}/${vars.nfsShares.pxebootImages.subpath} ${vars.lanCidr}${vars.nfsShares.options}
+    '';
  };

  # mountd (20048) is needed for showmount/NFSv3 mount protocol — without it
@@ -25,10 +25,13 @@ let
  '';
 in
 {
-  imports = [
-    ./set-locale.nix
-    ../ipa/client.nix
-  ];
+  imports =
+    [
+      # Include the results of the hardware scan.
+      #      ./hardware-configuration.nix
+      ./set-locale.nix
+      ../ipa/client.nix
+    ];

  # System-wide shell config so all users (including IPA accounts) get the
  # same management aliases as the local nixos user's Home Manager provides.
@@ -39,7 +42,11 @@ in
    };
    interactiveShellInit = buildImageFn;
  };
-  networking.networkmanager.enable = true;
+  # Use the GRUB 2 boot loader.
+  # boot.loader.grub.enable = true;
+  #boot.loader.grub.device = "/dev/sda"; # or "nodev" for efi only
+
+  networking.networkmanager.enable = true; # Easiest to use and most distros use this by default.

  # Recommended over the true default (bypasses ZFS's own import safeguards)
  # per the option's own docs; matches hosts/docker/host.nix and
@@ -1,35 +0,0 @@
-# Shared activation-script logic to preserve the SSH host key across
-# nixos-rebuild on platforms that embed the key via environment.etc (lxc and
-# proxmox).  When NIXOS_HOST_KEYS_DIR is not set the key is absent from
-# environment.etc, and NixOS's etc activation removes any /etc file not in
-# the new generation — which would destroy the live key and break sops-nix
-# decryption permanently.  These scripts save the key to /run before etc
-# removes it, then restore it afterward.
-#
-# Explicit deps enforce the correct ordering: without them the topological
-# sort places preserveSshHostKey after etc (confirmed live on lxc-tor-relay:
-# position 7 vs etc's position 5), so the key is gone before it can be saved.
-_: {
-  system.activationScripts = {
-    preserveSshHostKey = ''
-      if [ -f /etc/ssh/ssh_host_ed25519_key ]; then
-        cp /etc/ssh/ssh_host_ed25519_key /run/sshd-host-key-preserve.tmp
-        cp /etc/ssh/ssh_host_ed25519_key.pub /run/sshd-host-key-preserve.pub.tmp
-      fi
-    '';
-
-    restoreSshHostKey = {
-      deps = [ "etc" ];
-      text = ''
-        if [ ! -f /etc/ssh/ssh_host_ed25519_key ] && [ -f /run/sshd-host-key-preserve.tmp ]; then
-          install -m 0600 /run/sshd-host-key-preserve.tmp /etc/ssh/ssh_host_ed25519_key
-          install -m 0644 /run/sshd-host-key-preserve.pub.tmp /etc/ssh/ssh_host_ed25519_key.pub
-        fi
-        rm -f /run/sshd-host-key-preserve.tmp /run/sshd-host-key-preserve.pub.tmp
-      '';
-    };
-
-    etc = { deps = [ "preserveSshHostKey" ]; };
-    setupSecrets = { deps = [ "restoreSshHostKey" ]; };
-  };
-}
@@ -1,10 +1,26 @@
-{ pkgs, vars, ... }:
+{ lib, pkgs, vars, ... }:

 {
+  #  virtualisation.docker.enable = true;
  virtualisation.docker = {
    enable = true;
    package = pkgs.docker;
+    #  listenOptions = [
+    #  "unix:///var/run/docker.sock"
+    #  "tcp://0.0.0.0:2375"
+    #];
+
+    #  daemon.settings = {
+    #    metrics-addr = "0.0.0.0:9323";
+    #    experimental = true;
+    #  };
  };
+  # Pin the docker group GID to match the IPA "docker-access" group so that
+  # IPA group membership alone grants access to the Docker socket. Any user
+  # whose supplementary groups (resolved by SSSD from IPA) include GID
+  # vars.dockerAccessGid will pass the socket group-permission check without
+  # any per-host users.groups.docker.members entry.
+  users.groups.docker.gid = lib.mkForce vars.dockerAccessGid;
  users.users.${vars.primaryUser}.extraGroups = [ "docker" ];
  environment.systemPackages = with pkgs; [
    docker-compose
@@ -38,47 +38,113 @@ lib.mkIf enabled {
  networking.domain = lib.mkDefault vars.homeDomain;
  networking.nameservers = lib.mkDefault [ vars.domainControllerIp ];

-  security.ipa = {
-    enable = true;
-    domain = vars.homeDomain;
-    inherit realm;
-    server = vars.ipaServer;
-    certificate = caCertPkg;
-    inherit basedn;
-    ipaHostname = fqdn;
-    offlinePasswords = true;
-    cacheCredentials = true;
+  security = {
+    ipa = {
+      enable = true;
+      domain = vars.homeDomain;
+      inherit realm;
+      server = vars.ipaServer;
+      certificate = caCertPkg;
+      inherit basedn;
+      ipaHostname = fqdn;
+      offlinePasswords = true;
+      cacheCredentials = true;
+    };
+
+    # Create the home directory on first login if it doesn't exist yet.
+    # IPA users have no pre-created home on the host; without this sshd
+    # opens a session to a non-existent directory and resets the connection.
+    # lightdm also needs this so the GUI login path can create the home dir
+    # if it was not pre-seeded by the tmpfiles rule above (e.g. on first boot
+    # before SSSD has resolved the user).
+    pam.services = {
+      sshd.makeHomeDir = true;
+      lightdm.makeHomeDir = true;
+    };
+
+    # HM with useUserPackages = true (flake.nix) sets users.users.${ipaUser}.packages,
+    # which forces the stub into /etc/passwd. pam_sss.so with the "localusers" flag
+    # (added by NixOS when SSSD is enabled) then skips SSSD for any user it finds in
+    # local /etc/passwd — including this stub — falling through to pam_unix, which has
+    # no password for the stub → sudo auth always fails.
+    #
+    # Fix: NOPASSWD for the IPA user. The IPA user already authenticated to reach a
+    # shell (SSH public key from IPA or Kerberos), so re-prompting via a broken PAM
+    # path is security theater on a single-admin homelab.
+    sudo.extraRules = [{
+      users = [ vars.ipaUser ];
+      commands = [{ command = "ALL"; options = [ "NOPASSWD" ]; }];
+    }];
  };

-  # Fetch SSH public keys from IPA so users can log in with the key stored
-  # in their IPA profile rather than needing ~/.ssh/authorized_keys on every
-  # host. sss_ssh_authorizedkeys queries SSSD (which queries IPA LDAP).
-  #
-  # /nix/store is 1775 (group-writable by nixbld). OpenSSH 10.0+ rejects
-  # AuthorizedKeysCommand binaries whose path contains any group-writable
-  # component, silently skipping the command. Copy to /usr/local/bin (all
-  # components root-owned, 755) so the path passes sshd's safety check.
-  systemd.tmpfiles.rules = [
-    "d /usr/local 0755 root root - -"
-    "d /usr/local/bin 0755 root root - -"
-    "C+ /usr/local/bin/sss_ssh_authorizedkeys 0555 root root - ${pkgs.sssd}/bin/sss_ssh_authorizedkeys"
-    # Pre-create the IPA user's home dir so Home Manager activation succeeds
-    # even before their first login. On a fresh system SSSD may not have
-    # resolved the user yet — tmpfiles warns and skips in that case (non-fatal),
-    # and pam_mkhomedir covers the first-login path as a fallback.
-    "d /home/${vars.ipaUser} 0700 ${vars.ipaUser} ${vars.ipaUser} - -"
-  ];
+  systemd = {
+    # Fetch SSH public keys from IPA so users can log in with the key stored
+    # in their IPA profile rather than needing ~/.ssh/authorized_keys on every
+    # host. sss_ssh_authorizedkeys queries SSSD (which queries IPA LDAP).
+    #
+    # /nix/store is 1775 (group-writable by nixbld). OpenSSH 10.0+ rejects
+    # AuthorizedKeysCommand binaries whose path contains any group-writable
+    # component, silently skipping the command. Copy to /usr/local/bin (all
+    # components root-owned, 755) so the path passes sshd's safety check.
+    tmpfiles.rules = [
+      "d /usr/local 0755 root root - -"
+      "d /usr/local/bin 0755 root root - -"
+      "C+ /usr/local/bin/sss_ssh_authorizedkeys 0555 root root - ${pkgs.sssd}/bin/sss_ssh_authorizedkeys"
+      # Pre-create the IPA user's home dir so Home Manager activation succeeds
+      # even before their first login. On a fresh system SSSD may not have
+      # resolved the user yet — tmpfiles warns and skips in that case (non-fatal),
+      # and pam_mkhomedir covers the first-login path as a fallback.
+      "d /home/${vars.ipaUser} 0700 ${vars.ipaUser} ${vars.ipaUser} - -"
+    ];
+
+    # security.ipa enables Kerberos (security.krb5) which causes systemd to
+    # start auth-rpcgss-module.service and rpc-gssd.service for Kerberos NFS
+    # authentication. LXC containers can't load the auth_rpcgss kernel module
+    # and don't have /var/lib/nfs/rpc_pipefs, so both services fail.
+    #
+    # The NixOS IPA module already adds a drop-in for auth-rpcgss-module.service
+    # with ConditionPathExists=/etc/krb5.keytab. We use lib.mkForce to win the
+    # text conflict and add ConditionVirtualization=!container alongside it so
+    # the service is skipped (not failed) in containers that do have a keytab.
+    # Same fix for rpc-gssd.service which also fails in containers.
+    units = lib.mkIf config.boot.isContainer {
+      "auth-rpcgss-module.service" = {
+        overrideStrategy = "asDropinIfExists";
+        text = lib.mkForce ''
+          [Unit]
+          ConditionPathExists=
+          ConditionPathExists=/etc/krb5.keytab
+          ConditionVirtualization=!container
+        '';
+      };
+      # rpc-gssd also has ConditionPathExists from the NixOS IPA module (and an
+      # X-Restart-Triggers store path from systemd.nix). Use mkForce to win;
+      # omit X-Restart-Triggers since this service is skipped in containers anyway.
+      "rpc-gssd.service" = {
+        overrideStrategy = "asDropinIfExists";
+        text = lib.mkForce ''
+          [Unit]
+          ConditionPathExists=
+          ConditionPathExists=/etc/krb5.keytab
+          ConditionVirtualization=!container
+        '';
+      };
+    };
+
+    # home-manager-<user>.service fails on first enrollment because /home/wayne
+    # doesn't exist until the user's first login (pam_mkhomedir creates it then).
+    # ConditionPathExists makes systemd skip the service (exit 0, condition not
+    # met) instead of failing. After first login the dir exists and subsequent
+    # rebuilds activate HM normally.
+    services."home-manager-${vars.ipaUser}".unitConfig.ConditionPathExists =
+      "/home/${vars.ipaUser}";
+  };

  services.openssh.extraConfig = ''
    AuthorizedKeysCommand /usr/local/bin/sss_ssh_authorizedkeys %u
    AuthorizedKeysCommandUser nobody
  '';

-  # Create the home directory on first login if it doesn't exist yet.
-  # IPA users have no pre-created home on the host; without this sshd
-  # opens a session to a non-existent directory and resets the connection.
-  security.pam.services.sshd.makeHomeDir = true;
-
  # Host keytab: pre-provisioned on the IPA server, sops-encrypted binary.
  # Placed at /etc/krb5.keytab before SSSD starts so the host authenticates
  # to IPA without running ipa-client-install.
@@ -92,44 +158,6 @@ lib.mkIf enabled {
    restartUnits = [ "sssd.service" ];
  };

-  # security.ipa enables Kerberos (security.krb5) which causes systemd to
-  # start auth-rpcgss-module.service and rpc-gssd.service for Kerberos NFS
-  # authentication. LXC containers can't load the auth_rpcgss kernel module
-  # and don't have /var/lib/nfs/rpc_pipefs, so both services fail.
-  #
-  # The NixOS IPA module already adds a drop-in for auth-rpcgss-module.service
-  # with ConditionPathExists=/etc/krb5.keytab. We use lib.mkForce to win the
-  # text conflict and add ConditionVirtualization=!container alongside it so
-  # the service is skipped (not failed) in containers that do have a keytab.
-  # Same fix for rpc-gssd.service which also fails in containers.
-  systemd.units = lib.mkIf config.boot.isContainer {
-    "auth-rpcgss-module.service" = {
-      overrideStrategy = "asDropinIfExists";
-      text = lib.mkForce ''
-        [Unit]
-        ConditionPathExists=
-        ConditionPathExists=/etc/krb5.keytab
-        ConditionVirtualization=!container
-      '';
-    };
-    # rpc-gssd also has ConditionPathExists from the NixOS IPA module (and an
-    # X-Restart-Triggers store path from systemd.nix). Use mkForce to win;
-    # omit X-Restart-Triggers since this service is skipped in containers anyway.
-    "rpc-gssd.service" = {
-      overrideStrategy = "asDropinIfExists";
-      text = lib.mkForce ''
-        [Unit]
-        ConditionPathExists=
-        ConditionPathExists=/etc/krb5.keytab
-        ConditionVirtualization=!container
-      '';
-    };
-  };
-
-  # Home Manager config for the IPA primary user, applied on every enrolled
-  # host. Manages what IPA doesn't: dotfiles, user-scoped packages, session
-  # variables. Switch-nix/Test-nix/buildImage are system-wide (configuration.nix)
-  # so they don't need to be repeated here.
  # NixOS requires isNormalUser/isSystemUser + group on any entry in
  # users.users. HM with useUserPackages = true (set in flake.nix) adds a stub
  # entry for each HM user so it can install packages to
@@ -137,15 +165,6 @@ lib.mkIf enabled {
  # With security.ipa setting "passwd: sss files" in nsswitch, SSSD's IPA entry
  # takes priority for NSS lookups — this local stub is only a fallback when
  # SSSD is unreachable (at which point auth fails anyway).
-  # HM with useUserPackages = true (flake.nix) sets users.users.${ipaUser}.packages,
-  # which forces the stub into /etc/passwd. pam_sss.so with the "localusers" flag
-  # (added by NixOS when SSSD is enabled) then skips SSSD for any user it finds in
-  # local /etc/passwd — including this stub — falling through to pam_unix, which has
-  # no password for the stub → sudo auth always fails.
-  #
-  # Fix: NOPASSWD for the IPA user. The IPA user already authenticated to reach a
-  # shell (SSH public key from IPA or Kerberos), so re-prompting via a broken PAM
-  # path is security theater on a single-admin homelab.
  users.users.${vars.ipaUser} = {
    isNormalUser = true;
    group = "users";
@@ -153,19 +172,6 @@ lib.mkIf enabled {
    createHome = false;
  };

-  # home-manager-<user>.service fails on first enrollment because /home/wayne
-  # doesn't exist until the user's first login (pam_mkhomedir creates it then).
-  # ConditionPathExists makes systemd skip the service (exit 0, condition not
-  # met) instead of failing. After first login the dir exists and subsequent
-  # rebuilds activate HM normally.
-  systemd.services."home-manager-${vars.ipaUser}".unitConfig.ConditionPathExists =
-    "/home/${vars.ipaUser}";
-
-  security.sudo.extraRules = [{
-    users = [ vars.ipaUser ];
-    commands = [{ command = "ALL"; options = [ "NOPASSWD" ]; }];
-  }];
-
  # Home Manager config for the IPA primary user, applied on every enrolled
  # host. Manages what IPA doesn't: dotfiles, user-scoped packages, session
  # variables. Switch-nix/Test-nix/buildImage are system-wide (configuration.nix)
@@ -52,7 +52,6 @@ in
  # LXC container does).
  imports = [
    (modulesPath + "/virtualisation/proxmox-lxc.nix")
-    ../common/preserve-ssh-host-key.nix
  ];

  proxmoxLXC = {
@@ -106,6 +105,49 @@ in
    };
  };

+  # NixOS's etc activation removes any /etc file that was in the previous
+  # generation's environment.etc but is absent from the current one — even
+  # real (non-symlink) copies.  On every routine nixos-rebuild switch/test that
+  # lacks NIXOS_HOST_KEYS_DIR the key is absent from environment.etc, so it
+  # gets removed as "obsolete".  sops-nix derives its age decryption key from
+  # /etc/ssh/ssh_host_ed25519_key; deletion cascades into every sops secret
+  # failing with "Error getting data key: 0 successful groups required, got 0".
+  #
+  # Fix: activation scripts that bracket the etc step, with explicit deps
+  # to enforce the correct ordering. Without deps the topological sort places
+  # preserveSshHostKey AFTER etc (confirmed live on a deployed lxc-tor-relay:
+  # position 7 vs etc's position 5) -- the key is already gone by the time it
+  # tries to save it. The etc/setupSecrets entries ADD to existing deps
+  # (types.listOf concatenates across module definitions).
+  system.activationScripts = {
+    # Saves the live key to /run before etc can delete it.
+    preserveSshHostKey = ''
+      if [ -f /etc/ssh/ssh_host_ed25519_key ]; then
+        cp /etc/ssh/ssh_host_ed25519_key /run/sshd-host-key-preserve.tmp
+        cp /etc/ssh/ssh_host_ed25519_key.pub /run/sshd-host-key-preserve.pub.tmp
+      fi
+    '';
+
+    # Reinstalls the key after etc runs if it was removed as "obsolete".
+    # The resulting file is not registered in environment.etc for either
+    # generation, so subsequent rebuilds leave it alone permanently.
+    restoreSshHostKey = {
+      deps = [ "etc" ];
+      text = ''
+        if [ ! -f /etc/ssh/ssh_host_ed25519_key ] && [ -f /run/sshd-host-key-preserve.tmp ]; then
+          install -m 0600 /run/sshd-host-key-preserve.tmp /etc/ssh/ssh_host_ed25519_key
+          install -m 0644 /run/sshd-host-key-preserve.pub.tmp /etc/ssh/ssh_host_ed25519_key.pub
+        fi
+        rm -f /run/sshd-host-key-preserve.tmp /run/sshd-host-key-preserve.pub.tmp
+      '';
+    };
+
+    # Force etc to wait until the key is saved, and sops to wait until the
+    # key is restored. Without these the topological sort breaks the chain.
+    etc = { deps = [ "preserveSshHostKey" ]; };
+    setupSecrets = { deps = [ "restoreSshHostKey" ]; };
+  };
+
  # virtualisation/proxmox-lxc.nix (imported above) registers the Nix
  # store DB via a systemd service (register-nix-paths) -- it never runs
  # an activation script at all. Confirmed live this means neither
@@ -34,7 +34,6 @@ in
    ../hardware-configuration/vm/proxmox.nix
    ../boot/efi.nix
    ../disko/proxmox.nix
-    ../common/preserve-ssh-host-key.nix
  ];

  environment.etc = lib.mkIf hasKeyForThisTarget {
@@ -47,4 +46,36 @@ in
      mode = "0644";
    };
  };
+
+  # NixOS's etc activation removes any /etc file that was in the previous
+  # generation's environment.etc but is absent from the current one. Since
+  # the SSH key is only in environment.etc during the --impure build (when
+  # NIXOS_HOST_KEYS_DIR is set), normal rebuilds would remove it as
+  # "obsolete". These scripts mirror lxc.nix's approach: save the live key
+  # before etc runs, restore it after. Without the explicit deps, the
+  # topological sort places preserveSshHostKey after etc (confirmed live on
+  # lxc-tor-relay: position 7 vs etc's position 5), so the key is gone
+  # before it can be saved.
+  system.activationScripts = {
+    preserveSshHostKey = ''
+      if [ -f /etc/ssh/ssh_host_ed25519_key ]; then
+        cp /etc/ssh/ssh_host_ed25519_key /run/sshd-host-key-preserve.tmp
+        cp /etc/ssh/ssh_host_ed25519_key.pub /run/sshd-host-key-preserve.pub.tmp
+      fi
+    '';
+
+    restoreSshHostKey = {
+      deps = [ "etc" ];
+      text = ''
+        if [ ! -f /etc/ssh/ssh_host_ed25519_key ] && [ -f /run/sshd-host-key-preserve.tmp ]; then
+          install -m 0600 /run/sshd-host-key-preserve.tmp /etc/ssh/ssh_host_ed25519_key
+          install -m 0644 /run/sshd-host-key-preserve.pub.tmp /etc/ssh/ssh_host_ed25519_key.pub
+        fi
+        rm -f /run/sshd-host-key-preserve.tmp /run/sshd-host-key-preserve.pub.tmp
+      '';
+    };
+
+    etc = { deps = [ "preserveSshHostKey" ]; };
+    setupSecrets = { deps = [ "restoreSshHostKey" ]; };
+  };
 }
@@ -16,7 +16,7 @@
  serverIp = "192.168.2.226"; # server (NFS/ZFS) Proxmox VM LAN IP
  dockerIp = "192.168.2.225"; # docker Proxmox VM LAN IP
  pbsIp = "192.168.2.244"; # Proxmox Backup Server LAN IP (not NixOS-managed)
-  domainControllerIp = "192.168.2.253"; # FreeIPA domain controller — authoritative DNS for sweet.home (not NixOS-managed)
+  domainControllerIp = "192.168.2.253"; # FreeIPA domain controller / primary DNS (not NixOS-managed)
  ipaServer = "domain-controller.sweet.home"; # FreeIPA server hostname (used by security.ipa and Kerberos; must be a resolvable FQDN, not an IP)

  # Cross-host references (LAN hostnames/users other hosts reach over the network)
@@ -85,6 +85,12 @@
  # that IPA itself doesn't cover: dotfiles, user packages, session variables.
  ipaUser = "wayne";

+  # GID of the IPA "docker-access" group (GID 50010 on the IPA server).
+  # The local "docker" group is pinned to this GID on every host that runs
+  # Docker so that IPA group membership alone grants docker socket access -
+  # no per-host users.groups.docker.members entry for the IPA user needed.
+  dockerAccessGid = 50010;
+
  # HA file server cluster
  # LAN IPs (vmbr0 / ens18) — client-facing: iSCSI initiators, NFS, management.
  # Storage IPs (vmbr1 / ens19) — isolated internal bridge, used for DRBD