configuration.nix

@@ -4,12 +4,17 @@
   lib,
   hostInfo,
   customPkgs,
+  flakeRev,
   ...
 }:
 let
   inherit (hostInfo) paths;
 in
 {
+  imports = [ ./modules/autodeploy.nix ];
+
+  services.server-autodeploy.enable = true;
+
   assertions =
     let
       isMounted =
@@ -47,6 +52,11 @@ in
 
   time.timeZone = "UTC";
   system.stateVersion = "26.05";
+  system.nixos.label =
+    let
+      labelFile = ./.nixos-label;
+    in
+    if builtins.pathExists labelFile then lib.removeSuffix "\n" (builtins.readFile labelFile) else flakeRev;
 
   nix = {
     settings = {

flake.nix

@@ -11,6 +11,7 @@
 
   outputs =
     {
+      self,
       nixpkgs,
       mtce,
       microvm,
@@ -21,6 +22,8 @@
       inherit (nixpkgs) lib;
       pkgs = import nixpkgs { inherit system; };
 
+      flakeRev = self.shortRev or self.dirtyShortRev or "unknown";
+
       customPkgs = {
         hopper-rs = pkgs.callPackage ./packages/hopper-rs.nix { };
         sshpiper = pkgs.callPackage ./packages/sshpiper.nix { };
@@ -29,6 +32,7 @@
         server-rebuild = pkgs.callPackage ./packages/server-rebuild.nix { };
         server-status = pkgs.callPackage ./packages/server-status.nix { };
         server-kexec = pkgs.callPackage ./packages/server-kexec.nix { };
+        server-autodeploy = pkgs.callPackage ./packages/server-autodeploy.nix { };
       };
 
       ci = import ./ci.nix { inherit lib pkgs; };
@@ -51,7 +55,7 @@
 
       specialArgsFor = hostName: {
         hostInfo = hostInfoFor hostName;
-        inherit inputs customPkgs;
+        inherit inputs customPkgs flakeRev;
       };
 
       hostDefFor =
@@ -147,6 +151,7 @@
           server-rebuild
           server-status
           server-kexec
+          server-autodeploy
           ;
       };
     };

modules/autodeploy.nix

@@ -0,0 +1,89 @@
+{
+  config,
+  lib,
+  pkgs,
+  hostInfo,
+  customPkgs,
+  ...
+}:
+let
+  cfg = config.services.server-autodeploy;
+in
+{
+  options.services.server-autodeploy = {
+    enable = lib.mkEnableOption "automatic deployment from signed git tags";
+
+    interval = lib.mkOption {
+      type = lib.types.str;
+      default = "15min";
+    };
+
+    branch = lib.mkOption {
+      type = lib.types.str;
+      default = "master";
+    };
+
+    giteaUrl = lib.mkOption {
+      type = lib.types.str;
+      default = "https://git.floweytf.com";
+    };
+
+    giteaRepo = lib.mkOption {
+      type = lib.types.str;
+      default = "server/server-config";
+    };
+
+    tokenFile = lib.mkOption {
+      type = lib.types.str;
+      default = "${hostInfo.paths.secrets}/gitea-autodeploy-token";
+    };
+
+    allowedSignersFile = lib.mkOption {
+      type = lib.types.str;
+      default = "${hostInfo.paths.secrets}/autodeploy-allowed-signers";
+    };
+
+    stateDir = lib.mkOption {
+      type = lib.types.str;
+      default = "/persist/@autodeploy";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.server-autodeploy = {
+      description = "Deploy latest signed tag";
+      after = [ "network-online.target" ];
+      wants = [ "network-online.target" ];
+
+      environment = {
+        GITEA_URL = cfg.giteaUrl;
+        GITEA_REPO = cfg.giteaRepo;
+        TOKEN_FILE = cfg.tokenFile;
+        ALLOWED_SIGNERS = cfg.allowedSignersFile;
+        DEPLOY_BRANCH = cfg.branch;
+        STATE_DIR = cfg.stateDir;
+        REPO_DIR = "/persist/@configuration";
+      };
+
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = lib.getExe customPkgs.server-autodeploy;
+        TimeoutStartSec = "30min";
+      };
+
+      path = [
+        config.nix.package
+        pkgs.nixos-rebuild
+      ];
+    };
+
+    systemd.timers.server-autodeploy = {
+      wantedBy = [ "timers.target" ];
+      timerConfig = {
+        OnBootSec = "2min";
+        OnUnitActiveSec = cfg.interval;
+        RandomizedDelaySec = "2min";
+      };
+    };
+  };
+}

packages/server-autodeploy.nix

@@ -0,0 +1,14 @@
+{
+  writeShellApplication,
+  git,
+  curl,
+  jq,
+}:
+import ./mk-script.nix { inherit writeShellApplication; } {
+  name = "server-autodeploy";
+  runtimeInputs = [
+    git
+    curl
+    jq
+  ];
+}

scripts/server-autodeploy.sh

@@ -0,0 +1,58 @@
+REPO_DIR="${REPO_DIR:-/persist/@configuration}"
+STATE_DIR="${STATE_DIR:-/persist/@autodeploy}"
+BRANCH="origin/${DEPLOY_BRANCH:-master}"
+
+mkdir -p "$STATE_DIR"
+exec 9>"$STATE_DIR/lock"
+flock -n 9 || { echo "another deploy running"; exit 0; }
+
+report_status() {
+  [[ -f "$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)" \
+      '{state:$s,description:$d,context:$c}')" \
+    "$GITEA_URL/api/v1/repos/$GITEA_REPO/statuses/$3" >/dev/null
+}
+
+cd "$REPO_DIR"
+
+export GIT_CONFIG_COUNT=2
+export GIT_CONFIG_KEY_0=gpg.format
+export GIT_CONFIG_VALUE_0=ssh
+export GIT_CONFIG_KEY_1=gpg.ssh.allowedSignersFile
+export GIT_CONFIG_VALUE_1="$ALLOWED_SIGNERS"
+
+git fetch origin --tags --prune-tags
+
+latest=$(git describe --abbrev=0 "$BRANCH" 2>/dev/null) || {
+  echo "no tags on $BRANCH"
+  exit 0
+}
+
+current=$(cat "$STATE_DIR/tag" 2>/dev/null) || true
+[[ "$latest" != "$current" ]] || { echo "already at $latest"; exit 0; }
+
+echo "new tag: $latest (current: ${current:-none})"
+
+git tag -v "$latest" || {
+  sha=$(git rev-list -1 "$latest")
+  report_status "failure" "tag signature verification failed" "$sha"
+  exit 1
+}
+
+sha=$(git rev-list -1 "$latest")
+report_status "pending" "deploying $latest" "$sha"
+
+# 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"
+  report_status "success" "deployed $latest" "$sha"
+  echo "deployed $latest"
+else
+  report_status "failure" "nixos-rebuild failed" "$sha"
+  exit 1
+fi