1 files changed, 56 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/docker/retry.py b/testing/web-platform/tests/tools/docker/retry.py
new file mode 100755
index 0000000000..8ecf5874fe
--- /dev/null
+++ b/testing/web-platform/tests/tools/docker/retry.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+import argparse
+import subprocess
+import time
+import sys
+
+
+def get_args() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--delay", action="store", type=float, default=3, help="Initial delay before retry, in seconds")
+    parser.add_argument("--count", action="store", type=int, default=5, help="Total number of tries")
+    parser.add_argument("--factor", action="store", type=float, default=2, help="Exponential backoff factor")
+    parser.add_argument("cmd", nargs=argparse.REMAINDER)
+    return parser
+
+
+def log(value: str) -> None:
+    print(value)
+    sys.stdout.flush()
+
+
+def main() -> None:
+    args = get_args().parse_args()
+
+    if not args.cmd:
+        log("No command supplied")
+        sys.exit(1)
+
+    retcode = None
+
+    for n in range(args.count):
+        try:
+            log("Running %s [try %d/%d]" % (" ".join(args.cmd), (n+1), args.count))
+            subprocess.check_call(args.cmd)
+        except subprocess.CalledProcessError as e:
+            retcode = e.returncode
+        else:
+            log("Command succeeded")
+            retcode = 0
+            break
+
+        if args.factor == 0:
+            wait_time = (n+1) * args.delay
+        else:
+            wait_time = args.factor**n * args.delay
+        if n < args.count - 1:
+            log("Command failed, waiting %s seconds to retry" % wait_time)
+            time.sleep(wait_time)
+        else:
+            log("Command failed, out of retries")
+
+    sys.exit(retcode)
+
+
+if __name__ == "__main__":
+    main()