ci: retry benchmark image pulls before generating datasets

Signed-off-by: WenyXu <wenymedia@gmail.com>

.github/scripts/pull-benchmark-image.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Pull only: never retry database writes, benchmarks, or cloud provisioning.
+set -euo pipefail
+
+if [[ $# != 1 || -z "$1" || "$1" == -* ]]; then
+    echo "Usage: $0 IMAGE" >&2
+    exit 2
+fi
+image=$1
+attempts=3
+for ((attempt=1; attempt<=attempts; attempt++)); do
+    echo "Pulling $image (attempt $attempt/$attempts)" >&2
+    if timeout --kill-after=10s 180s docker pull "$image"; then
+        exit 0
+    else
+        status=$?
+    fi
+    if ((attempt == attempts)); then
+        echo "Failed to pull $image after $attempts attempts (exit $status)" >&2
+        exit "$status"
+    fi
+    delay=$((attempt * 10))
+    echo "Pull failed (exit $status); retrying in ${delay}s" >&2
+    sleep "$delay"
+done