feat: allow arguments to be passed to templates

templates/_utils.tpl

@@ -3,32 +3,22 @@
 {{- /*
 Merge one or more YAML templates and output the result.
 This takes an list of values:
-- the first item is the top context
-- the rest items are template names of the templates, the former one will override the latter.
+- the top context
+- [optional] zero or more template args
+- [optional] the template name of the overrides (destination)
+- the template name of the base (source)
 */ -}}
 {{- define "common.utils.merge" -}}
 {{- $top := first . -}}
-{{- $dest := dict -}}
-{{- range (rest .) -}}
-  {{- $src := fromYaml (include . $top) | default (dict) -}}
-  {{- $dest = merge $dest $src -}}
+{{- $tplName := last . -}}
+{{- $args := initial . -}}
+{{- if typeIs "string" (last $args) -}}
+  {{- $overridesName := last $args -}}
+  {{- $args = initial $args -}}
+  {{- $tpl := fromYaml (include $tplName $args) | default (dict) -}}
+  {{- $overrides := fromYaml (include $overridesName $args) | default (dict) -}}
+  {{- toYaml (merge $overrides $tpl) -}}
+{{- else -}}
+  {{- include $tplName $args -}}
 {{- end -}}
-{{- toYaml $dest -}}
-{{- end -}}
-
-{{- /*
-Flatten list of arguments before rendering the given template.
-This takes an list of values:
-- the first item is the template name to be rendered
-- the second item is either an list of arguments or a single argument
-- the rest items are the appended arguments
-*/ -}}
-{{- define "common.utils.flattenCall" -}}
-{{- $tpl := first . -}}
-{{- $args := index . 1 -}}
-{{- if not (typeIs "[]interface {}" $args) -}}
-  {{- $args = list $args -}}
-{{- end -}}
-{{- $args = concat $args (slice . 2) -}}
-{{- include $tpl $args -}}
 {{- end -}}