Double quote variables

This is to to prevent globs and multiple shell words being interpreted
where one is expected.

hack/build-and-push.sh

@@ -94,14 +94,14 @@ find task/*/*/ -maxdepth 0 -type d | awk -F '/' '{ print $0, $2, $3 }' | \
 while read -r task_dir task_name task_version
 do
     prepared_task_file="${WORKDIR}/$task_name-${task_version}.yaml"
-    if [ -f $task_dir/$task_name.yaml ]; then
-        cp $task_dir/$task_name.yaml $prepared_task_file
-        task_file_sha=$(git log -n 1 --pretty=format:%H -- $task_dir/$task_name.yaml)
-    elif [ -f $task_dir/kustomization.yaml ]; then
-        oc kustomize $task_dir > $prepared_task_file
-        task_file_sha=$(sha256sum $prepared_task_file | awk '{print $1}')
+    if [ -f "$task_dir/$task_name.yaml" ]; then
+        cp "$task_dir/$task_name.yaml" "$prepared_task_file"
+        task_file_sha=$(git log -n 1 --pretty=format:%H -- "$task_dir/$task_name.yaml")
+    elif [ -f "$task_dir/kustomization.yaml" ]; then
+        oc kustomize "$task_dir" > "$prepared_task_file"
+        task_file_sha=$(sha256sum "$prepared_task_file" | awk '{print $1}')
     else
-        echo Unknown task in $task_dir
+        echo Unknown task in "$task_dir"
         continue
     fi
     repository=${TEST_REPO_NAME:-task-${task_name}}