feat: support arbitrary shellcheck config paths (#5571)

- Support passing an arbitrary path to the shellcheck configuration file
  with the BASH_CONFIG_FILE_NAME variable. This brings shellcheck in
  line with other linters that support configuration files.
- Enable shellcheck external sources using a directive in the
  configuration file, so users can eventually override it if not needed.
- Export command configuration variables that subprocesses might need.

Close #5414

README.md

@@ -193,6 +193,7 @@ You can configure super-linter using the following environment variables:
 | **ANSIBLE_CONFIG_FILE**                         | `.ansible-lint.yml`             | Filename for [Ansible-lint configuration](https://ansible.readthedocs.io/projects/lint/configuring/) (ex: `.ansible-lint`, `.ansible-lint.yml`)                                                                      |
 | **ANSIBLE_DIRECTORY**                           | `/ansible`                      | Flag to set the root directory for Ansible file location(s), relative to `DEFAULT_WORKSPACE`. Set to `.` to use the top-level of the `DEFAULT_WORKSPACE`.                                                            |
 | **BASH_EXEC_IGNORE_LIBRARIES**                  | `false`                         | If set to `true`, shell files with a file extension and no shebang line are ignored when checking if the executable bit is set.                                                                                      |
+| **BASH_FILE_NAME**                              | `.shellcheckrc`                 | Filename for [Shellcheck](https://github.com/koalaman/shellcheck/blob/master/shellcheck.1.md#rc-files)                                                                                                               |
 | **BASH_SEVERITY**                               | `style`                         | Specify the minimum severity of errors to consider in shellcheck. Valid values in order of severity are error, warning, info and style.                                                                              |
 | **CHECKOV_FILE_NAME**                           | `.checkov.yaml`                 | Configuration filename for Checkov.                                                                                                                                                                                  |
 | **CLANG_FORMAT_FILE_NAME**                      | `.clang-format`                 | Configuration filename for [clang-format](https://clang.llvm.org/docs/ClangFormatStyleOptions.html).                                                                                                                 |

TEMPLATES/.shellcheckrc

@@ -1 +1,5 @@
+# Look for 'source'd files relative to the checked script
 source-path=SCRIPTDIR
+
+# Allow opening any 'source'd file, even if not specified as input
+external-sources=true

lib/functions/linterCommands.sh

@@ -13,8 +13,12 @@
 # shellcheck disable=SC2034 # Variable is referenced in other scripts
 LINTER_COMMANDS_ARRAY_ANSIBLE=(ansible-lint -c "${ANSIBLE_LINTER_RULES}" "&& echo \"Linted: {}\"")
 LINTER_COMMANDS_ARRAY_ARM=(pwsh -NoProfile -NoLogo -Command "\"Import-Module ${ARM_TTK_PSD1} ; \\\${config} = \\\$(Import-PowerShellDataFile -Path ${ARM_LINTER_RULES}) ; Test-AzTemplate @config -TemplatePath '{}'; if (\\\${Error}.Count) { exit 1 }\"")
-LINTER_COMMANDS_ARRAY_BASH=(shellcheck --color --external-sources)
+LINTER_COMMANDS_ARRAY_BASH=(shellcheck --color --rcfile "${BASH_LINTER_RULES}")
+# This check and the BASH_SEVERITY variable are needed until Shellcheck supports
+# setting severity using its config file.
+# Ref: https://github.com/koalaman/shellcheck/issues/2178
 if [ -n "${BASH_SEVERITY}" ]; then
+  export BASH_SEVERITY
   LINTER_COMMANDS_ARRAY_BASH+=(--severity="${BASH_SEVERITY}")
 fi
 LINTER_COMMANDS_ARRAY_BASH_EXEC=(bash-exec '{}')
@@ -44,6 +48,7 @@ LINTER_COMMANDS_ARRAY_EDITORCONFIG=(editorconfig-checker -config "${EDITORCONFIG
 LINTER_COMMANDS_ARRAY_ENV=(dotenv-linter)
 LINTER_COMMANDS_ARRAY_GITHUB_ACTIONS=(actionlint -config-file "${GITHUB_ACTIONS_LINTER_RULES}")
 if [ "${GITHUB_ACTIONS_COMMAND_ARGS}" != "null" ] && [ -n "${GITHUB_ACTIONS_COMMAND_ARGS}" ]; then
+  export GITHUB_ACTIONS_COMMAND_ARGS
   LINTER_COMMANDS_ARRAY_GITHUB_ACTIONS+=("${GITHUB_ACTIONS_COMMAND_ARGS}")
 fi
 LINTER_COMMANDS_ARRAY_GITLEAKS=(gitleaks detect --no-banner --no-git --redact --config "${GITLEAKS_LINTER_RULES}" --verbose --source)
@@ -66,6 +71,7 @@ LINTER_COMMANDS_ARRAY_JSX=(eslint --no-eslintrc -c "${JSX_LINTER_RULES}")
 LINTER_COMMANDS_ARRAY_KOTLIN=(ktlint "{/}")
 LINTER_COMMANDS_ARRAY_KUBERNETES_KUBECONFORM=(kubeconform -strict)
 if [ "${KUBERNETES_KUBECONFORM_OPTIONS}" != "null" ] && [ -n "${KUBERNETES_KUBECONFORM_OPTIONS}" ]; then
+  export KUBERNETES_KUBECONFORM_OPTIONS
   LINTER_COMMANDS_ARRAY_KUBERNETES_KUBECONFORM+=("${KUBERNETES_KUBECONFORM_OPTIONS}")
 fi
 LINTER_COMMANDS_ARRAY_LATEX=(chktex -q -l "${LATEX_LINTER_RULES}")
@@ -85,6 +91,7 @@ LINTER_COMMANDS_ARRAY_NATURAL_LANGUAGE=(textlint -c "${NATURAL_LANGUAGE_LINTER_R
 LINTER_COMMANDS_ARRAY_OPENAPI=(spectral lint -r "${OPENAPI_LINTER_RULES}" -D)
 LINTER_COMMANDS_ARRAY_PERL=(perlcritic)
 if [ "${PERL_PERLCRITIC_OPTIONS}" != "null" ] && [ -n "${PERL_PERLCRITIC_OPTIONS}" ]; then
+  export PERL_PERLCRITIC_OPTIONS
   LINTER_COMMANDS_ARRAY_PERL+=("${PERL_PERLCRITIC_OPTIONS}")
 fi
 LINTER_COMMANDS_ARRAY_PHP_BUILTIN=(php -l -c "${PHP_BUILTIN_LINTER_RULES}")

lib/linter.sh

@@ -149,6 +149,7 @@ debug "TFLINT_LOG: ${TFLINT_LOG}"
 ANSIBLE_FILE_NAME="${ANSIBLE_CONFIG_FILE:-.ansible-lint.yml}"
 # shellcheck disable=SC2034  # Variable is referenced indirectly
 ARM_FILE_NAME=".arm-ttk.psd1"
+BASH_FILE_NAME="${BASH_FILE_NAME:-".shellcheckrc"}"
 BASH_SEVERITY="${BASH_SEVERITY:-""}"
 CHECKOV_FILE_NAME="${CHECKOV_FILE_NAME:-".checkov.yaml"}"
 # shellcheck disable=SC2034  # Variable is referenced indirectly

test/inspec/super-linter/controls/super_linter.rb

@@ -501,6 +501,7 @@ control "super-linter-validate-files" do
     "/action/lib/.automation/.ruby-lint.yml",
     "/action/lib/.automation/.ruff.toml",
     "/action/lib/.automation/.scalafmt.conf",
+    "/action/lib/.automation/.shellcheckrc",
     "/action/lib/.automation/.snakefmt.toml",
     "/action/lib/.automation/.sql-config.json",
     "/action/lib/.automation/.sqlfluff",