Add a script to watch builts for a release tag

.scripts/watch-builds.sh

@@ -0,0 +1,142 @@
+#!/usr/bin/env bash
+# Watch the build runs for a release tag and re-run failed jobs until they all
+# pass. A single tag triggers one build run per product, and transient
+# registry/network blips fail runs that a plain re-run would fix; this saves
+# clicking "Re-run failed jobs" by hand.
+#
+# Every failure is retried up to --max-attempts and then given up on, so a real
+# build break gets retried too. Check the log of anything that gives up.
+#
+# Needs: gh (authenticated) and jq.
+
+set -euo pipefail
+
+interval=60
+max_attempts=10
+dry_run=false
+tag=
+
+usage() {
+  cat <<'EOF'
+Usage: watch-builds.sh TAG [options]
+
+  TAG                git tag to watch (required), e.g. 26.7.1
+
+  --interval SECS    seconds between polls (default: 60)
+  --max-attempts N   attempts per run before giving up (default: 10)
+  --dry-run          list what would be re-run without triggering it
+  -h, --help         show this help
+EOF
+}
+
+while [ $# -gt 0 ]; do
+  case $1 in
+    --interval)     interval=$2; shift 2 ;;
+    --max-attempts) max_attempts=$2; shift 2 ;;
+    --dry-run)      dry_run=true; shift ;;
+    -h|--help)      usage; exit 0 ;;
+    -*)             echo "watch-builds.sh: unknown option: $1" >&2; usage >&2; exit 2 ;;
+    *)              tag=$1; shift ;;
+  esac
+done
+
+if [ -z "$tag" ]; then
+  echo "watch-builds.sh: a TAG is required" >&2
+  usage >&2
+  exit 2
+fi
+
+for bin in gh jq; do
+  command -v "$bin" >/dev/null || { echo "watch-builds.sh: $bin is not on PATH" >&2; exit 1; }
+done
+
+# Attempts already triggered per run id, seeded from each run's real run_attempt
+# so re-runs done by hand in the UI still count towards the cap.
+declare -A attempts
+declare -A gave_up
+
+# A run is worth re-running only if it actually failed. In-progress and
+# successful runs are left alone; a cancelled run was stopped on purpose.
+is_retryable() {
+  case $1 in
+    failure|timed_out|startup_failure) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
+printf 'Watching %s (poll %ss, max-attempts %s%s)\n\n' \
+  "$tag" "$interval" "$max_attempts" "$([ "$dry_run" = true ] && echo ', dry-run')"
+
+while true; do
+  # --limit 100 comfortably covers the one-run-per-product fan-out.
+  runs=$(gh run list --branch "$tag" --limit 100 \
+    --json databaseId,workflowName,status,conclusion 2>/dev/null || echo '[]')
+
+  if [ "$(jq length <<<"$runs")" -eq 0 ]; then
+    echo "No runs found for $tag, waiting..."
+    sleep "$interval"
+    continue
+  fi
+
+  running=0 succeeded=0 retryable=0 gaveup=0 triggered=0
+
+  while IFS=$'\t' read -r id name status conclusion; do
+    if [ "$status" != completed ]; then
+      running=$((running + 1))
+      printf '  %-6s %s (%s)\n' wait "$name" "$status"
+      continue
+    fi
+
+    if [ "$conclusion" = success ]; then
+      succeeded=$((succeeded + 1))
+      printf '  %-6s %s\n' ok "$name"
+      continue
+    fi
+
+    # Completed but not successful. Only failures are re-run; anything else
+    # (e.g. cancelled) is reported and left as-is.
+    if [ -z "${gave_up[$id]:-}" ] && ! is_retryable "$conclusion"; then
+      printf '  %-6s %s (%s)\n' skip "$name" "$conclusion"
+      continue
+    fi
+
+    if [ -z "${attempts[$id]:-}" ]; then
+      attempts[$id]=$(gh run view "$id" --json runAttempt --jq .runAttempt 2>/dev/null || echo 1)
+    fi
+
+    if [ -n "${gave_up[$id]:-}" ] || [ "${attempts[$id]}" -ge "$max_attempts" ]; then
+      gave_up[$id]=1
+      gaveup=$((gaveup + 1))
+      printf '  %-6s %s (gave up after %s attempts: %s)\n' FAIL "$name" "${attempts[$id]}" "$conclusion"
+      continue
+    fi
+
+    retryable=$((retryable + 1))
+    next=$((attempts[$id] + 1))
+    if [ "$dry_run" = true ]; then
+      printf '  %-6s %s (would be attempt %s)\n' retry "$name" "$next"
+    elif gh run rerun "$id" --failed >/dev/null 2>&1; then
+      attempts[$id]=$next
+      triggered=$((triggered + 1))
+      printf '  %-6s %s (attempt %s)\n' retry "$name" "$next"
+    else
+      # A rerun is refused until the run has fully settled; the next poll retries.
+      printf '  %-6s %s (rerun deferred)\n' retry "$name"
+    fi
+  done < <(jq -r 'sort_by(.workflowName)[] | [.databaseId, .workflowName, .status, .conclusion] | @tsv' <<<"$runs")
+
+  printf '\n  %s | ok %s, waiting %s, retrying %s, gave up %s (triggered %s)\n\n' \
+    "$(date +%H:%M:%S)" "$succeeded" "$running" "$retryable" "$gaveup" "$triggered"
+
+  # Nothing running and nothing left to retry means we are done.
+  if [ "$running" -eq 0 ] && [ "$retryable" -eq 0 ]; then
+    if [ "$gaveup" -gt 0 ]; then
+      echo "Done: $gaveup run(s) still failing after $max_attempts attempts. Check their logs."
+      exit 1
+    fi
+    echo "Done: all $succeeded run(s) for $tag passed."
+    exit 0
+  fi
+
+  sleep "$interval"
+done