ci: Add shellcheck

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

.gitlab-ci.yml

@@ -110,6 +110,8 @@ review:
       codespell --ignore-words-list=keypair,sorce,ned,nd,ue || ERROR=1;
       ./.gitlab-ci/clang-format-check.sh || ERROR=1;
       ./.gitlab-ci/git-check-signoff-trailer.sh ${CI_MERGE_REQUEST_DIFF_BASE_SHA} || ERROR=1;
+      ./.gitlab-ci/git-check-signoff-trailer.sh ${CI_MERGE_REQUEST_DIFF_BASE_SHA} || ERROR=1;
+      ./.gitlab-ci/shellcheck.sh || ERROR=1;
       exit $ERROR
   # the format is not always matching our intentions
   allow_failure: true

.gitlab-ci/shellcheck.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+# Simplified and de-github-ed version of
+# https://github.com/ludeeus/action-shellcheck/blob/master/action.yaml
+
+statuscode=0
+
+declare -a filepaths
+shebangregex="^#! */[^ ]*/(env *)?[abk]*sh"
+set -f # temporarily disable globbing so that globs in inputs aren't expanded
+
+while IFS= read -r -d '' file; do
+  filepaths+=("$file")
+done < <(find . \
+    -type f \
+    '(' \
+    -name '*.bash' \
+    -o -name '.bashrc' \
+    -o -name 'bashrc' \
+    -o -name '.bash_aliases' \
+    -o -name '.bash_completion' \
+    -o -name '.bash_login' \
+    -o -name '.bash_logout' \
+    -o -name '.bash_profile' \
+    -o -name 'bash_profile' \
+    -o -name '*.ksh' \
+    -o -name 'suid_profile' \
+    -o -name '*.zsh' \
+    -o -name '.zlogin' \
+    -o -name 'zlogin' \
+    -o -name '.zlogout' \
+    -o -name 'zlogout' \
+    -o -name '.zprofile' \
+    -o -name 'zprofile' \
+    -o -name '.zsenv' \
+    -o -name 'zsenv' \
+    -o -name '.zshrc' \
+    -o -name 'zshrc' \
+    -o -name '*.sh' \
+    -o -path '*/.profile' \
+    -o -path '*/profile' \
+    -o -name '*.shlib' \
+    ')' \
+    -print0)
+
+while IFS= read -r -d '' file; do
+    head -n1 "$file" | grep -Eqs "$shebangregex" || continue
+    filepaths+=("$file")
+done < <(find . \
+    -type f ! -name '*.*' -perm /111 \
+    -print0)
+
+shellcheck "${filepaths[@]}" || statuscode=$?
+
+set +f # re-enable globbing
+
+exit "$statuscode"