add a retry-command script (#27754)

* add a retry-command script

* add license header to retry script

.github/actions/install-external-tools/action.yml

@@ -21,15 +21,15 @@ runs:
     - uses: ./.github/actions/set-up-staticcheck
       # We assume that the Go toolchain will be managed by the caller workflow so we don't set one
       # up here.
-    - run: go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
+    - run: ./.github/scripts/retry-command.sh go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
       shell: bash
-    - run: go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
+    - run: ./.github/scripts/retry-command.sh go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
       shell: bash
-    - run: go install github.com/favadi/protoc-go-inject-tag@latest
+    - run: ./.github/scripts/retry-command.sh go install github.com/favadi/protoc-go-inject-tag@latest
       shell: bash
-    - run: go install golang.org/x/tools/cmd/goimports@latest
+    - run: ./.github/scripts/retry-command.sh go install golang.org/x/tools/cmd/goimports@latest
       shell: bash
-    - run: go install github.com/golangci/revgrep/cmd/revgrep@latest
+    - run: ./.github/scripts/retry-command.sh go install github.com/golangci/revgrep/cmd/revgrep@latest
       shell: bash
-    - run: go install github.com/loggerhead/enumer@latest
+    - run: ./.github/scripts/retry-command.sh go install github.com/loggerhead/enumer@latest
       shell: bash

.github/scripts/retry-command.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: BUSL-1.1
+set -euo pipefail
+
+tries=5
+count=0
+
+until "$@"
+do
+  if [ $count -eq $tries ]; then
+    echo "tried $count times, exiting"
+    exit 1
+  fi
+  ((count++))
+  echo "trying again, attempt $count"
+  sleep 2
+done