ci(metis): retry Go module network calls in quality gate

scripts/quality_gate.sh

@@ -6,16 +6,37 @@ build_dir="${repo_root}/build"
 gopath_bin="$(go env GOPATH)/bin"
 junit_report="${gopath_bin}/go-junit-report"
 
+run_with_retry() {
+  local attempts="$1"
+  shift
+  local try=1
+  local delay=3
+  local rc=0
+  while true; do
+    "$@" && return 0
+    rc=$?
+    if [[ "${try}" -ge "${attempts}" ]]; then
+      return "${rc}"
+    fi
+    echo "[quality] retry ${try}/${attempts} after rc=${rc}: $*" >&2
+    sleep "${delay}"
+    delay=$((delay * 2))
+    try=$((try + 1))
+  done
+}
+
 mkdir -p "${build_dir}"
 
 if [ ! -x "${junit_report}" ]; then
-  go install github.com/jstemmer/go-junit-report/v2@latest
+  run_with_retry 3 go install github.com/jstemmer/go-junit-report/v2@latest
 fi
 
 cd "${repo_root}"
+export GOPROXY="${GOPROXY:-https://proxy.golang.org,direct}"
+run_with_retry 4 go mod download
 
 set +e
-go test -v -count=1 -coverprofile="${build_dir}/coverage.out" ./... > "${build_dir}/test.out" 2>&1
+run_with_retry 3 go test -v -count=1 -coverprofile="${build_dir}/coverage.out" ./... > "${build_dir}/test.out" 2>&1
 test_rc=$?
 set -e