chore(ci): add shellcheck (#7)

Reviewed-on: https://gitea.com/gitea/helm-actions/pulls/7
Reviewed-by: justusbunsi <justusbunsi@noreply.gitea.com>
Co-authored-by: Markus Pesch <markus.pesch@cryptic.systems>
Co-committed-by: Markus Pesch <markus.pesch@cryptic.systems>

.editorconfig

@@ -9,4 +9,7 @@ indent_size = 2
 end_of_line = lf
 charset = utf-8
 trim_trailing_whitespace = false
-insert_final_newline = false
+insert_final_newline = false
+
+[Makefile]
+indent_style = tab

.gitea/workflows/shellcheck.yml

@@ -0,0 +1,14 @@
+name: Lint Shell files
+
+on:
+  pull_request:
+    branches: ["*"]
+    types: ["opened", "reopened", "synchronize"]
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4.2.2
+      - run: apt update --yes && apt install --yes shellcheck
+      - run: find . -type f -name "*.sh" -exec shellcheck -a {} \;

Makefile

@@ -16,4 +16,7 @@ unittests-helm:
 .PHONY: helm
 update-helm-dependencies:
 	helm dependency update
-  
+
+.PHONY: yamllint
+yamllint:
+	yamllint -c .yamllint .

scripts/token.sh

@@ -8,9 +8,14 @@ check_token() {
   set +e
 
   echo "Checking for existing token..."
-  token="$(kubectl get secret "$SECRET_NAME" -o jsonpath="{.data['token']}" 2> /dev/null)"
-  [ $? -ne 0 ] && return 1
-  [ -z "$token" ] && return 2
+  if ! token=$(kubectl get secret "${SECRET_NAME}" -o jsonpath="{.data['token']}" 2> /dev/null); then
+    return 1
+  fi
+
+  if [ -z "${token}" ]; then
+    return 2
+  fi
+
   return 0
 }