Add an ns1 test-and-deploy workflow for the Go MCP server.

scripts/deploy-138.sh tests with Go 1.26.9, swaps the live binary, and rolls back if port 8000 stops answering. Port 0 in the embedded NATS listener now picks an ephemeral port so the test can run while 4222 is already taken.

.forgejo/workflows/test-and-deploy.yml

@@ -0,0 +1,24 @@
+name: test-and-deploy
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: 138
+    steps:
+      - uses: actions/checkout@v4
+      - name: Unit tests
+        run: bash scripts/test-138.sh
+
+  deploy-138:
+    needs: test
+    if: success() && github.event_name != 'pull_request' && github.ref == 'refs/heads/main'
+    runs-on: 138
+    steps:
+      - uses: actions/checkout@v4
+      - name: Deploy with automatic health rollback
+        run: bash scripts/deploy-138.sh

README.md

@@ -22,7 +22,7 @@ cd verae-mcp-timestamping-server-go
 go build -o bin/verae-mcp-timestamping-server ./cmd/verae-mcp-timestamping-server
 ```
 
-Requires Go 1.26+. Design: `docs/superpowers/specs/2026-09-29-go-mcp-timestamping-server-design.md`. Shadow systemd unit (not installed by this build): `deploy/verae-mcp-timestamping-go.service`.
+Requires Go 1.26+. Design: `docs/superpowers/specs/2026-09-29-go-mcp-timestamping-server-design.md`. The ns1 unit `verae-mcp-timestamping.service` runs this binary from `/opt/verae/verae-mcp-timestamping-server-go/bin`. `.forgejo/workflows/test-and-deploy.yml` tests on the `138` runner and `scripts/deploy-138.sh` swaps that binary, with a probe of `http://127.0.0.1:8000/mcp` and rollback to the previous file.
 
 ## Usage
 

internal/embednats/server.go

@@ -119,5 +119,15 @@ func splitHostPort(listen string) (string, int, error) {
 	if host == "" {
 		host = "127.0.0.1"
 	}
+	// nats-server treats port 0 as its default (4222), which is already taken
+	// on ns1. Bind an ephemeral port and hand that number to the server.
+	if port == 0 {
+		ln, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
+		if err != nil {
+			return "", 0, fmt.Errorf("embednats: ephemeral listen: %w", err)
+		}
+		port = ln.Addr().(*net.TCPAddr).Port
+		ln.Close()
+	}
 	return host, port, nil
 }

scripts/deploy-138.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env bash
+# Test, build, and swap the Go MCP binary on ns1.
+# Does not restart verae-timestamping-svc or forgejo-runner, and does not read secret files.
+set -euo pipefail
+
+LOCK="${LOCK:-/tmp/verae-mcp-go-deploy.lock}"
+DEST="${DEST:-/opt/verae/verae-mcp-timestamping-server-go/bin/verae-mcp-timestamping-server}"
+SERVICE="${SERVICE:-verae-mcp-timestamping.service}"
+PROBE="${PROBE:-http://127.0.0.1:8000/mcp}"
+GO_ROOT="${GO_ROOT:-/usr/local/lib/go1.26.9}"
+GO_TARBALL="${GO_TARBALL:-go1.26.9.linux-amd64.tar.gz}"
+GO_SHA256="${GO_SHA256:-42d158b4d8f7b61ac0a830567c940a86098fb7aac52e467a5ebec03ef5cc2f8d}"
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+
+mkdir -p "$(dirname "$LOCK")"
+exec 9>"$LOCK"
+if ! flock -n 9; then
+  echo "another mcp deploy holds the lock" >&2
+  exit 1
+fi
+
+ensure_go() {
+  if [[ -x "$GO_ROOT/bin/go" ]] && "$GO_ROOT/bin/go" version | grep -q 'go1.26.9 '; then
+    export PATH="$GO_ROOT/bin:$PATH"
+    return
+  fi
+  local tmp
+  tmp="$(mktemp -d)"
+  curl -fsSL -o "$tmp/go.tgz" "https://go.dev/dl/${GO_TARBALL}"
+  echo "${GO_SHA256}  ${tmp}/go.tgz" | sha256sum -c -
+  tar -C "$tmp" -xzf "$tmp/go.tgz"
+  sudo rm -rf "$GO_ROOT"
+  sudo mv "$tmp/go" "$GO_ROOT"
+  rm -rf "$tmp"
+  export PATH="$GO_ROOT/bin:$PATH"
+}
+
+probe_ok() {
+  local code
+  code="$(curl -s -o /dev/null -w '%{http_code}' --max-time 5 "$PROBE" || true)"
+  [[ -n "$code" && "$code" != "000" ]]
+}
+
+wait_probe() {
+  local i
+  for i in 1 2 3 4 5 6 7 8; do
+    if probe_ok; then
+      return 0
+    fi
+    sleep 1
+  done
+  return 1
+}
+
+swap_binary() {
+  local src="$1"
+  sudo systemctl stop "$SERVICE" || true
+  local n=0
+  while (( n < 5 )); do
+    if sudo cp "$src" "$DEST"; then
+      sudo chown verae-mcp:verae-mcp "$DEST"
+      sudo chmod 755 "$DEST"
+      sudo systemctl start "$SERVICE"
+      return 0
+    fi
+    n=$((n + 1))
+    sleep 1
+    sudo systemctl stop "$SERVICE" || true
+  done
+  echo "could not replace $DEST" >&2
+  sudo systemctl start "$SERVICE" || true
+  return 1
+}
+
+rollback() {
+  local latest
+  latest="$(ls -1t "${DEST}.bak-"* 2>/dev/null | head -1 || true)"
+  if [[ -z "$latest" ]]; then
+    echo "no backup to roll back to" >&2
+    sudo systemctl start "$SERVICE" || true
+    exit 1
+  fi
+  swap_binary "$latest"
+  if wait_probe; then
+    echo "rolled back to $latest (probe ok)"
+    return 0
+  fi
+  echo "rollback probe still failing" >&2
+  return 1
+}
+
+if [[ "${1:-}" == "--rollback" ]]; then
+  rollback
+  exit $?
+fi
+
+ensure_go
+cd "$ROOT"
+go test ./... -count=1
+go build -o /tmp/verae-mcp-timestamping-server-new ./cmd/verae-mcp-timestamping-server
+if ! grep -a -q 'verae-meta-git/1' /tmp/verae-mcp-timestamping-server-new; then
+  echo "built binary is missing verae-meta-git/1" >&2
+  exit 1
+fi
+
+if [[ "${1:-}" == "--test-only" ]]; then
+  echo "tests ok"
+  exit 0
+fi
+
+ts="$(date -u +%Y%m%dT%H%M%SZ)"
+sudo cp -a "$DEST" "${DEST}.bak-${ts}"
+if ! swap_binary /tmp/verae-mcp-timestamping-server-new; then
+  rollback || true
+  exit 1
+fi
+if ! wait_probe; then
+  echo "new binary failed probe; rolling back" >&2
+  rollback || true
+  exit 1
+fi
+echo "deployed ${ts} probe ok"

scripts/test-138.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Unit-test the Go MCP server with Go 1.26. Does not restart a service.
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+exec bash "$ROOT/scripts/deploy-138.sh" --test-only