bug: fix autodeploy generation naming (#12)

Co-authored-by: Floweynt <server-n0@mail.floweytf.com>
Reviewed-on: #12

.github/workflows/diff-pr.yml

@@ -17,10 +17,18 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
+          ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
 
+      - name: merge base branch
+        run: |
+          git config user.email "ci@localhost"
+          git config user.name "CI"
+          git fetch origin ${{ github.event.pull_request.base.ref }}
+          git merge --no-edit origin/${{ github.event.pull_request.base.ref }}
+
       - name: worktree base for diff
-        run: git worktree add "$RUNNER_TEMP/base" "${{ github.event.pull_request.base.sha }}"
+        run: git worktree add "$RUNNER_TEMP/base" "origin/${{ github.event.pull_request.base.ref }}"
 
       - name: build closures and render diff
         run: |

.github/workflows/flake-update.yml

@@ -5,21 +5,19 @@ on:
     - cron: "17 4 * * *"
   workflow_dispatch:
 
-permissions:
-  contents: write
-  pull-requests: write
-
 jobs:
   update:
     runs-on: nix
     steps:
       - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
 
       - run: nix flake update -L
 
       - name: open/update PR
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ secrets.BOT_TOKEN }}
           API: ${{ github.api_url }}
           REPO: ${{ github.repository }}
         run: |

ci.py

@@ -8,6 +8,7 @@ import re
 import subprocess
 import subprocess_tee
 import sys
+import urllib.error
 import urllib.request
 from collections import Counter
 from pathlib import Path
@@ -26,6 +27,10 @@ def git(*args, check=True):
     return run("git", *args, check=check, capture_output=True)
 
 
+class GiteaError(Exception):
+    pass
+
+
 def gitea(method, path, body=None):
     url = f'{os.environ["API"]}/repos/{os.environ["REPO"]}{path}'
     data = json.dumps(body).encode() if body is not None else None
@@ -37,7 +42,11 @@ def gitea(method, path, body=None):
         with urllib.request.urlopen(req) as resp:
             raw = resp.read()
     except urllib.error.HTTPError as e:
-        sys.exit(f"gitea {method} {path}: {e.code} {e.reason}\n{e.read().decode()}")
+        try:
+            detail = json.loads(e.read()).get("message", e.reason)
+        except (json.JSONDecodeError, UnicodeDecodeError):
+            detail = e.reason
+        raise GiteaError(f"{method} {path}: {e.code} {detail}") from None
     return json.loads(raw) if raw else None
 
 
@@ -466,16 +475,24 @@ def open_pr(args):
 
     host = os.environ["API"].removesuffix("/api/v1")
     auth = base64.b64encode(f'token:{os.environ["GH_TOKEN"]}'.encode()).decode()
-    git("-c", f"http.extraHeader=Authorization: Basic {auth}",
-        "push", "-f", f'{host}/{os.environ["REPO"]}.git', f"HEAD:{args.branch}")
+    push = git("-c", f"http.extraHeader=Authorization: Basic {auth}",
+               "push", "-f", f'{host}/{os.environ["REPO"]}.git', f"HEAD:{args.branch}",
+               check=False)
+    if push.returncode != 0:
+        raise RuntimeError(f"git push failed:\n{push.stderr}")
 
-    owner = os.environ["REPO"].split("/")[0]
-    if gitea("GET", f"/pulls?state=open&head={owner}:{args.branch}"):
+    pulls = gitea("GET", f"/pulls?state=open&base_branch={args.base}")
+    existing = next((pr for pr in pulls if pr["head"]["ref"] == args.branch), None)
+    if existing:
+        print(f"PR #{existing['number']} already open, pushed update")
         return
     labels = [label_id(args.label)] if args.label else []
-    gitea("POST", "/pulls",
-          {"title": args.title, "head": args.branch, "base": args.base,
-           "body": Path(args.body_file).read_text(), "labels": labels})
+    pr = gitea("POST", "/pulls",
+               {"title": args.title, "head": args.branch, "base": args.base,
+                "body": Path(args.body_file).read_text(), "labels": labels})
+    if not pr or "number" not in pr:
+        raise GiteaError(f"POST /pulls: unexpected response: {json.dumps(pr)}")
+    print(f"opened PR #{pr['number']}")
 
 
 def main():

configuration.nix

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

dsl.nix

@@ -222,13 +222,15 @@ rec {
     : Bind mounts, keyed by mount point.
 
     `resources.devices`
-    : Host device nodes to expose, as paths, added to the unit's
-      `DeviceAllow=`. nspawn populates a handful of privileged devices
-      (`/dev/kvm`, `/dev/net/tun`, ...) into the container's own `/dev` once
-      the cgroup allows it, and silently skips ones the host doesn't have -
-      no `resources.fs` bind mount needed. Nodes keep their host ownership,
-      so a consumer inside needs `isolation.privateUsers = "identity"` for
-      the owning gid to mean anything.
+    : 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.
@@ -295,6 +297,10 @@ 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
@@ -381,7 +387,7 @@ rec {
       nixosContainer = {
         inherit autoStart privateUsers;
         bindMounts = { };
-        extraFlags = bindMountExtraFlags;
+        extraFlags = bindMountExtraFlags ++ deviceFlags;
         privateNetwork = true;
         extraVeths = linkVeths;
         config =

modules/autodeploy.nix

@@ -39,9 +39,19 @@ in
       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 {
@@ -58,6 +68,8 @@ 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

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

scripts/server-autodeploy.sh

@@ -6,12 +6,15 @@ 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/$3" >/dev/null
 }
@@ -24,9 +27,9 @@ export GIT_CONFIG_VALUE_0=ssh
 export GIT_CONFIG_KEY_1=gpg.ssh.allowedSignersFile
 export GIT_CONFIG_VALUE_1="$ALLOWED_SIGNERS"
 
-git fetch origin --tags --prune-tags
+runas git fetch origin --tags --prune-tags
 
-latest=$(git describe --abbrev=0 "$BRANCH" 2>/dev/null) || {
+latest=$(runas git describe --abbrev=0 "$BRANCH" 2>/dev/null) || {
   echo "no tags on $BRANCH"
   exit 0
 }
@@ -36,19 +39,20 @@ current=$(cat "$STATE_DIR/tag" 2>/dev/null) || true
 
 echo "new tag: $latest (current: ${current:-none})"
 
-git tag -v "$latest" || {
-  sha=$(git rev-list -1 "$latest")
+runas git tag -v "$latest" || {
+  sha=$(runas git rev-list -1 "$latest")
   report_status "failure" "tag signature verification failed" "$sha"
   exit 1
 }
 
-sha=$(git rev-list -1 "$latest")
+sha=$(runas git rev-list -1 "$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}#$(hostname)"
+runas git checkout "$latest"
+runas tee .nixos-label <<< "$latest" >/dev/null
+runas git add .nixos-label
 
-if nixos-rebuild switch --flake "$flake_url"; then
+if nixos-rebuild switch --flake ".#$HOSTNAME"; then
   echo "$latest" > "$STATE_DIR/tag"
   report_status "success" "deployed $latest" "$sha"
   echo "deployed $latest"

tests/server-n0/integration.py

@@ -336,9 +336,28 @@ with subtest("(functional): published ports follow the container's lifetime"):
 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, [])):