Added shellcheck

Makefile

@@ -11,6 +11,9 @@ ruff: ## Run Ruff linter
 docs-style: ## Check documentation strings in all Python sources from this repository
 	pydocstyle .
 
+shellcheck: ## Run shellcheck
+	./shellcheck.sh
+
 help: ## Show this help screen
 	@echo 'Usage: make <OPTIONS> ... <TARGETS>'
 	@echo ''

shellcheck.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+# Copyright 2020 Red Hat, Inc
+#
+# 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.
+
+if ! command -v shellcheck > /dev/null 2>&1; then
+    scversion="stable" # or "v0.4.7", or "latest"
+    wget -qO- "https://github.com/koalaman/shellcheck/releases/download/${scversion?}/shellcheck-${scversion?}.linux.x86_64.tar.xz" | tar -xJv
+    shellcheck-stable/shellcheck --version
+    shellcheck-stable/shellcheck --exclude=SC2230 -- *.sh
+else
+    shellcheck --exclude=SC2230 -- *.sh
+fi