fix failing passes

configuration.nix

@@ -19,10 +19,9 @@ in
     giteaRepo = "server/server-config";
     tokenFile = "${hostInfo.paths.secrets}/gitea-autodeploy-token";
     allowedSigners = [
-      "flowey@arch namespaces=\"git\" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPaGpTX3EzfezVc2nl3MgsKVamYYP2h2VJaRny8pZkvi"
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPaGpTX3EzfezVc2nl3MgsKVamYYP2h2VJaRny8pZkvi flowey@arch"
     ];
     stateDir = hostInfo.paths.config;
-    repoOwner = "server";
   };
 
   assertions =

containers/server-n0/mail.nix

@@ -146,8 +146,6 @@ let
 in
 mkContainer {
   inherit name;
-  includedInTests = false; # TODO: fixme, clearly mail is flakey
-
   net.access = [ { to = "@internet"; } ];
   svc.autoStart = true;
   net.forward.tcp = [

containers/server-n0/ssh.nix

@@ -75,6 +75,15 @@ let
       packages = with pkgs; [ tmux ] ++ packages;
       miscProperties = self._sshpiperRegister routingInfo;
     };
+
+  kvmTrait = {
+    containerConfig =
+      { pkgs, ... }:
+      {
+        users.users.runner.extraGroups = [ "kvm" ];
+        environment.systemPackages = [ pkgs.qemu_kvm ];
+      };
+  };
 in
 {
   ssh-admin = mkSsh {
@@ -117,27 +126,32 @@ in
   ssh-generic = mkSsh {
     name = "ssh-generic";
     net.access = [ { to = "@internet"; } ];
-    # /dev/kvm keeps its host ownership, so the kvm gid must not be shifted.
-    isolation.privateUsers = "identity";
     resources = {
       fs."/home/runner/data" = {
         hostPath = "${data}/ssh/generic";
         isReadOnly = false;
       };
-      devices = [ "/dev/kvm" ];
       mem = "16G";
       cpu = 65;
     };
-    packages = with pkgs; [ qemu_kvm ];
-    traits = [
+    traits = [ kvmTrait ];
+    isolation.allowedDevices = [
       {
-        containerConfig =
-          { config, ... }:
-          {
-            users.groups.kvm.gid = config.ids.gids.kvm;
-            users.users.runner.extraGroups = [ "kvm" ];
-          };
+        node = "/dev/kvm";
+        modifier = "rw";
       }
+      {
+        node = "/dev/vhost-net";
+        modifier = "rw";
+      }
+      {
+        node = "/dev/net/tun";
+        modifier = "rwm";
+      }
+    ];
+    isolation.additionalCapabilities = [
+      "CAP_NET_ADMIN"
+      "CAP_MKNOD"
     ];
     routingInfo = [
       {

dsl.nix

@@ -221,17 +221,6 @@ rec {
     `resources.fs`
     : Bind mounts, keyed by mount point.
 
-    `resources.devices`
-    : Host device nodes to expose, as paths. Bound into the container at the
-      same path and added to the unit's `DeviceAllow=` - the cgroup
-      permission alone doesn't get you a working node (nothing can `mknod` a
-      device inside a user namespace), and the bind alone leaves the cgroup
-      denying `open()`, so both are needed. The bind is unconditional, so
-      the device must actually exist on whatever host runs the container.
-      Nodes keep their host ownership, so a consumer inside needs
-      `isolation.privateUsers = "identity"` for the owning gid to mean
-      anything.
-
     `isolation.nixDaemon`
     : Whether the Nix daemon and CLI are available inside the container.
 
@@ -239,6 +228,17 @@ rec {
     : systemd-nspawn user namespacing; see `--private-users=` in
       systemd-nspawn(1). Bind mounts always go through idmapped `--bind`.
 
+    `isolation.allowedDevices`
+    : List of `{ node; modifier; }` host devices to grant the container's
+      cgroup access to; see `containers.<name>.allowedDevices` in the NixOS
+      manual. nspawn bind-mounts a handful of devices (`/dev/kvm`,
+      `/dev/net/tun`, ...) into the container itself once the cgroup allows it -
+      this doesn't need a matching `resources.fs` bind mount.
+
+    `isolation.additionalCapabilities`
+    : Extra Linux capabilities granted to the container; see
+      `containers.<name>.additionalCapabilities` in the NixOS manual.
+
     `miscProperties`
     : Arbitrary data attached to the result. Used for cross-container discovery
       via `collectContainers`.
@@ -281,15 +281,16 @@ rec {
       cpuQuota = "${toString (cpu * 100)}%";
       memoryMax = resources.mem or "512M";
       bindMounts = resources.fs or { };
-      devices = resources.devices or [ ];
       allowsNixDaemon = isolation.nixDaemon or false;
       privateUsers = isolation.privateUsers or "pick";
+      allowedDevices = isolation.allowedDevices or [ ];
+      additionalCapabilities = isolation.additionalCapabilities or [ ];
 
       allowInternet = hasInternetAccess access;
       allBindMounts = builtins.foldl' (acc: t: acc // (t.resources.fs or { })) { } traits // bindMounts;
       userModules = map mkUser (lib.concatMap (t: t.users or [ ]) traits ++ users);
       allPorts = ports ++ map (p: (normalizePort p).container) hostPorts;
-      useIdmap = privateUsers == "pick" || (builtins.isInt privateUsers && privateUsers > 0);
+      useIdmap = privateUsers != "no";
       bindMountExtraFlags = lib.mapAttrsToList (
         mountPoint: bm:
         (if bm.isReadOnly then "--bind-ro=" else "--bind=")
@@ -297,10 +298,6 @@ rec {
         + lib.optionalString useIdmap ":idmap"
       ) allBindMounts;
       bindMountHostPaths = map (bm: bm.hostPath) (lib.attrValues allBindMounts);
-      # DeviceAllow= alone only grants cgroup permission - nspawn can't
-      # mknod a device node inside a user namespace, so the node still
-      # needs an explicit bind from the host.
-      deviceFlags = map (d: "--bind=${d}") devices;
       inherit (deriveIdentity ifPrefix.nspawn name)
         iface
         mac
@@ -379,15 +376,19 @@ rec {
         hostAddr
         bindMountHostPaths
         includedInTests
-        devices
         ;
       bindMounts = allBindMounts;
       kind = "nspawn";
       miscProperties = flattenMiscProp self miscProperties;
       nixosContainer = {
-        inherit autoStart privateUsers;
+        inherit
+          autoStart
+          privateUsers
+          allowedDevices
+          additionalCapabilities
+          ;
         bindMounts = { };
-        extraFlags = bindMountExtraFlags ++ deviceFlags;
+        extraFlags = bindMountExtraFlags;
         privateNetwork = true;
         extraVeths = linkVeths;
         config =
@@ -520,7 +521,6 @@ rec {
         ;
       inherit needsGateway;
       bindMountHostPaths = map (s: s.source) shares;
-      devices = [ ];
       kind = "vm";
       miscProperties = flattenMiscProp self miscProperties;
       microvmConfig = {
@@ -957,7 +957,6 @@ rec {
           startLimitBurst = 5;
           startLimitIntervalSec = 120;
           unitConfig.RequiresMountsFor = c.bindMountHostPaths;
-          serviceConfig.DeviceAllow = map (d: "${d} rw") c.devices;
         };
 
       # the host end of a link, for both kinds. nixos-containers only configures
@@ -1317,7 +1316,6 @@ rec {
         HOST_ADDR = ${pyDict pyStr (lib.mapAttrs (_: c: c.hostAddr) autoStartTestContainers)}
         IFACE = ${pyDict pyStr (lib.mapAttrs (_: c: c.iface) autoStartTestContainers)}
         KIND = ${pyDict pyStr (lib.mapAttrs (_: c: c.kind) autoStartTestContainers)}
-        DEVICES = ${pyDict pyList (lib.mapAttrs (_: c: c.devices) autoStartTestContainers)}
         # only nspawn guests can be entered with nsenter; a vm has no host-side
         # netns, so every probe that runs *inside* a guest is limited to these
         enterable = [c for c in included if KIND[c] == "nspawn"]

modules/autodeploy.nix

@@ -38,20 +38,10 @@ in
       type = lib.types.listOf lib.types.str;
       default = [ ];
     };
-    
-    repoOwner = lib.mkOption {
-      type = lib.types.str;
-      description = "User that owns the configuration checkout";
-    };
 
     stateDir = lib.mkOption {
       type = lib.types.str;
     };
-
-    hostname = lib.mkOption {
-      type = lib.types.str;
-      default = config.networking.hostName;
-    };
   };
 
   config = lib.mkIf cfg.enable {
@@ -68,8 +58,6 @@ in
         DEPLOY_BRANCH = cfg.branch;
         STATE_DIR = cfg.stateDir;
         REPO_DIR = "/persist/@configuration";
-        REPO_OWNER = cfg.repoOwner;
-        HOSTNAME = cfg.hostname;
       };
 
       serviceConfig = {

packages/server-autodeploy.nix

@@ -3,8 +3,6 @@
   git,
   curl,
   jq,
-  util-linux,
-  openssh,
 }:
 import ./mk-script.nix { inherit writeShellApplication; } {
   name = "server-autodeploy";
@@ -12,7 +10,5 @@ import ./mk-script.nix { inherit writeShellApplication; } {
     git
     curl
     jq
-    util-linux
-    openssh
   ];
 }

scripts/server-autodeploy.sh

@@ -6,15 +6,12 @@ mkdir -p "$STATE_DIR"
 exec 9>"$STATE_DIR/lock"
 flock -n 9 || { echo "another deploy running"; exit 0; }
 
-runas() { runuser -u "$REPO_OWNER" -- "$@"; }
-
 report_status() {
-  echo "updating status to: $1 - $2"
   [[ -f "$TOKEN_FILE" ]] || return 0
   curl -sf -X POST \
     -H "Authorization: token $(<"$TOKEN_FILE")" \
     -H "Content-Type: application/json" \
-    -d "$(jq -n --arg s "$1" --arg d "$2" --arg c "deploy/$HOSTNAME" \
+    -d "$(jq -n --arg s "$1" --arg d "$2" --arg c "deploy/$(hostname)" \
       '{state:$s,description:$d,context:$c}')" \
     "$GITEA_URL/api/v1/repos/$GITEA_REPO/statuses/$3" >/dev/null
 }
@@ -27,9 +24,9 @@ export GIT_CONFIG_VALUE_0=ssh
 export GIT_CONFIG_KEY_1=gpg.ssh.allowedSignersFile
 export GIT_CONFIG_VALUE_1="$ALLOWED_SIGNERS"
 
-runas git fetch origin --tags --prune-tags
+git fetch origin --tags --prune-tags
 
-latest=$(runas git describe --abbrev=0 "$BRANCH" 2>/dev/null) || {
+latest=$(git describe --abbrev=0 "$BRANCH" 2>/dev/null) || {
   echo "no tags on $BRANCH"
   exit 0
 }
@@ -39,16 +36,17 @@ current=$(cat "$STATE_DIR/tag" 2>/dev/null) || true
 
 echo "new tag: $latest (current: ${current:-none})"
 
-runas git tag -v "$latest" || {
-  sha=$(runas git rev-list -1 "$latest")
+git tag -v "$latest" || {
+  sha=$(git rev-list -1 "$latest")
   report_status "failure" "tag signature verification failed" "$sha"
   exit 1
 }
 
-sha=$(runas git rev-list -1 "$latest")
+sha=$(git rev-list -1 "$latest")
 report_status "pending" "deploying $latest" "$sha"
 
-flake_url="git+${GITEA_URL}/${GITEA_REPO}?ref=refs/tags/${latest}&rev=${sha}#$HOSTNAME"
+# build from remote, pinned to the verified rev - no local checkout needed
+flake_url="git+${GITEA_URL}/${GITEA_REPO}?ref=refs/tags/${latest}&rev=${sha}#$(hostname)"
 
 if nixos-rebuild switch --flake "$flake_url"; then
   echo "$latest" > "$STATE_DIR/tag"

tests/server-n0/integration.py

@@ -27,7 +27,6 @@ if TYPE_CHECKING:
     HOST_ADDR: dict[str, str] = {}
     IFACE: dict[str, str] = {}
     KIND: dict[str, str] = {}
-    DEVICES: dict[str, list[str]] = {}
     EDGES: list[tuple[str, str, list[int], list[int]]] = []
     SSH_KEY: str = ""
     SSH_OPTS: str = ""
@@ -56,11 +55,6 @@ def container_pid(name):
     return server.succeed(f"machinectl show {name} -p Leader --value").strip()
 
 
-def ct_cmd(name, cmd):
-    pid = container_pid(name)
-    return f"{NSENTER} --mount=/proc/{pid}/ns/mnt --root=/proc/{pid}/root -- {SH} -c '{cmd}'"
-
-
 def net_cmd(name, cmd):
     pid = container_pid(name)
     return f"{NSENTER} --net=/proc/{pid}/ns/net -- {cmd}"
@@ -153,8 +147,6 @@ with subtest("(functional): web services respond"):
     for name, port in [("devenv", 8080), ("maven", 8080), ("git", 3000)]:
         server.succeed(net_cmd(name, f"{CURL} -sf --max-time 5 -o /dev/null http://{ADDR[name]}:{port}/ >&2"))
 
-# TODO: re-enable mail
-"""
 with subtest("(functional): mail accepts connections"):
     smtp_probe = net_cmd("mail", f"{SH} -c 'exec 3<>/dev/tcp/{ADDR['mail']}/25 && head -1 <&3'")
     server.wait_until_succeeds(f"{smtp_probe} | grep -q '^220'", timeout=60)
@@ -169,7 +161,6 @@ with subtest("(functional): mail accepts connections"):
         return greeting.strip().startswith("* OK")
 
     retry(imap_ready, timeout_seconds=60)
-"""
 
 with subtest("(functional): nginx proxies to backend containers"):
     server.succeed(
@@ -200,7 +191,7 @@ with subtest("(isolation): undeclared container edges are refused"):
         ("devenv", "git", 3000),
         ("git", "devenv", 8080),
         ("maven", "git", 3000),
-        # ("nginx", "mail", 25),
+        ("nginx", "mail", 25),
         ("ssh-botm", "ssh-admin", 22),
         ("overseer", "git", 3000),
     ]:
@@ -253,7 +244,7 @@ with subtest("(isolation): renaming the interface changes nothing"):
     rename(iface, "evil0")
     try:
         server.succeed(ct_connect("nginx", ADDR["git"], 3000))
-        # server.fail(ct_connect("nginx", ADDR["mail"], 25, timeout=2))
+        server.fail(ct_connect("nginx", ADDR["mail"], 25, timeout=2))
     finally:
         rename("evil0", iface)
 
@@ -332,40 +323,3 @@ with subtest("(functional): published ports follow the container's lifetime"):
     server.succeed("systemctl start container@nginx")
     server.wait_for_unit("container@nginx.service")
     internet.wait_until_succeeds(ext_connect(80), timeout=30)
-
-with subtest("(functional): declared devices are usable in-container"):
-    for name, devices in DEVICES.items():
-        for dev in devices:
-            # opened, not stat'd: without DeviceAllow= the node is still visible
-            server.succeed(ct_cmd(name, f"exec 3<> {dev}"))
-
-
-with subtest("(functional): /dev/kvm actually initializes, not just opens"):
-    # a wrong-gid or unmapped node still opens but fails the ioctls qemu
-    # needs, so boot with no disk (never completes) and kill it - the
-    # failure mode this catches is qemu refusing to start at all.
-    for name, devices in DEVICES.items():
-        if "/dev/kvm" not in devices:
-            continue
-        out = server.succeed(
-            ct_cmd(
-                name,
-                f"{TIMEOUT} 3 qemu-system-x86_64 -enable-kvm -m 256 -nographic -no-reboot "
-                ">/tmp/qemu.out 2>&1; cat /tmp/qemu.out",
-            )
-        )
-        assert "Permission denied" not in out, f"{name}: qemu couldn't use /dev/kvm:\n{out}"
-        assert "Could not access KVM" not in out, f"{name}: qemu couldn't use /dev/kvm:\n{out}"
-
-
-with subtest("(isolation): devices reach only the container that declared them"):
-    for name in enterable:
-        for dev in {d for ds in DEVICES.values() for d in ds} - set(DEVICES.get(name, [])):
-            server.fail(ct_cmd(name, f"test -e {dev}"))
-
-
-with subtest("(isolation): identity uid mapping keeps the user namespace"):
-    for name in (n for n, ds in DEVICES.items() if ds):
-        host_ns = server.succeed("readlink /proc/1/ns/user").strip()
-        ct_ns = server.succeed(f"readlink /proc/{container_pid(name)}/ns/user").strip()
-        assert host_ns != ct_ns, f"{name} shares the host user namespace"