From 66aa0427cda4e820ca37f2f6df797db7672d70bf Mon Sep 17 00:00:00 2001
From: Etienne Perot <eperot@google.com>
Date: Fri, 7 Oct 2022 15:14:03 -0700
Subject: [PATCH] Make BuildKite's docker runtime reload logic robust against
 empty runtime dict

PiperOrigin-RevId: 479678511
---
 .buildkite/hooks/post-command | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/.buildkite/hooks/post-command b/.buildkite/hooks/post-command
index 2e88eaf13..aa7b50e43 100644
--- a/.buildkite/hooks/post-command
+++ b/.buildkite/hooks/post-command
@@ -77,8 +77,11 @@ done
 set -euo pipefail
 
 # Remove all Docker runtimes that may be installed.
-if grep -qE runtimes /etc/docker/daemon.json; then
-  cat /etc/docker/daemon.json | jq 'del(.runtimes) + {runtimes: {}}' \
+num_docker_runtimes="$(jq \
+    '(if has("runtimes") then .runtimes else {} end) | length' \
+    < /etc/docker/daemon.json)"
+if [[ "$num_docker_runtimes" -gt 0 ]]; then
+  cat /etc/docker/daemon.json | jq 'del(.runtimes)' \
     | sudo tee /etc/docker/daemon.json.tmp
   sudo mv /etc/docker/daemon.json.tmp /etc/docker/daemon.json
   bash -c "$DOCKER_RELOAD_COMMAND"