Add SHA512 file to nightly build

PiperOrigin-RevId: 198745666
Change-Id: I38d4163cd65f1236b09ce4f6481197a9a9fd29f2

kokoro/gcp_ubuntu/release-nightly.cfg

@@ -2,9 +2,10 @@
 build_file: "repo/kokoro/gcp_ubuntu/run_build.sh"
 
 action {
-  # Upload only the runsc binary. It may be in multiple paths, so we must use
-  # the wildcard.
+  # Upload runsc binary and its checksum. It may be in multiple paths, so we
+  # must use the wildcard.
   define_artifacts {
     regex: "**/runsc"
+    regex: "**/runsc.sha512"
   }
 }

kokoro/gcp_ubuntu/run_build.sh

@@ -37,4 +37,6 @@ latest_dir="${KOKORO_ARTIFACTS_DIR}"/latest
 today_dir="${KOKORO_ARTIFACTS_DIR}"/"$(date -Idate)"
 mkdir -p "${latest_dir}" "${today_dir}"
 cp bazel-bin/runsc/linux_amd64_pure_stripped/runsc "${latest_dir}"
+sha512sum "${latest_dir}"/runsc | awk '{print $1 "  runsc"}' > "${latest_dir}"/runsc.sha512
 cp bazel-bin/runsc/linux_amd64_pure_stripped/runsc "${today_dir}"
+sha512sum "${today_dir}"/runsc | awk '{print $1} "  runsc"' > "${today_dir}"/runsc.sha512