Add an ensure shellcheck file

make lint runs shellcheck on all shell files

ensure-shellcheck.sh checks for macos

Update images/capi/hack/ensure-shellcheck.sh

Co-authored-by: Matt Boersma <[email protected]>

remove redundant code

make lint runs shellcheck on sh files

images/capi/Makefile

@@ -184,6 +184,7 @@ deps-lint: ## Installs/checks dependencies for image-builder code linting
 deps-lint: deps-common
 	hack/ensure-ansible-windows.sh
 	hack/ensure-ansible-lint.sh
+	hack/ensure-shellcheck.sh
 
 ## --------------------------------------
 ## Container variables
@@ -967,8 +968,11 @@ validate-all: ## Validates the Packer config for all build targets
 
 .PHONY: lint
 lint: ## Runs linters on image-builder code
+sh_files = $(shell find . -type f -name "*.sh")
 lint: deps-lint
 	ansible-lint ansible/
+# ignore error code since shellcheck exits with Error 1 if problems are found despite running properly
+	-@for f in $(sh_files); do (shellcheck -x $$f); done
 
 .PHONY: lint-fix
 lint-fix: ## Runs linters on image-builder code and fixes issues

images/capi/hack/ensure-shellcheck.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+# Copyright 2023 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+[[ -n ${DEBUG:-} ]] && set -o xtrace
+
+scversion="stable"
+
+if [[ "$OSTYPE" == "darwin"* ]]; then
+    operatingsystem="darwin.x86_64"
+else
+    operatingsystem="linux.x86_64"
+fi
+
+if command -v shellcheck >/dev/null 2>&1; then exit 0; fi
+
+wget -qO- "https://github.com/koalaman/shellcheck/releases/download/${scversion?}/shellcheck-${scversion?}.${operatingsystem?}.tar.xz" | tar -xJv
+cp "shellcheck-${scversion}/shellcheck" ~/.local/bin/
+rm -rf "./shellcheck-${scversion}"
+shellcheck --version