Method initFunMap

pkg/engine/engine.go:198–256

initFunMap creates the Engine's FuncMap and adds context-specific functions.

(t *template.Template)

// initFunMap creates the Engine's FuncMap and adds context-specific functions.
func (e Engine) initFunMap(t *template.Template) {
	funcMap := funcMap()
	includedNames := make(map[string]int)

	// Add the template-rendering functions here so we can close over t.
	funcMap["include"] = includeFun(t, includedNames)
	funcMap["tpl"] = tplFun(t, includedNames, e.Strict)

	// Add the `required` function here so we can use lintMode
	funcMap["required"] = func(warn string, val any) (any, error) {
		if val == nil {
			if e.LintMode {
				// Don't fail on missing required values when linting
				slog.Warn("missing required value", "message", warn)
				return "", nil
			}
			return val, errors.New(warnWrap(warn))
		} else if _, ok := val.(string); ok {
			if val == "" {
				if e.LintMode {
					// Don't fail on missing required values when linting
					slog.Warn("missing required values", "message", warn)
					return "", nil
				}
				return val, errors.New(warnWrap(warn))
			}
		}
		return val, nil
	}

	// Override sprig fail function for linting and wrapping message
	funcMap["fail"] = func(msg string) (string, error) {
		if e.LintMode {
			// Don't fail when linting
			slog.Info("funcMap fail", "message", msg)
			return "", nil
		}
		return "", errors.New(warnWrap(msg))
	}

	// If we are not linting and have a cluster connection, provide a Kubernetes-backed
	// implementation.
	if !e.LintMode && e.clientProvider != nil {
		funcMap["lookup"] = newLookupFunction(*e.clientProvider)
	}

	// When DNS lookups are not enabled override the sprig function and return
	// an empty string.
	if !e.EnableDNS {
		funcMap["getHostByName"] = func(_ string) string {
			return ""
		}
	}

	// Set custom template funcs
	maps.Copy(funcMap, e.CustomTemplateFuncs)

	t.Funcs(funcMap)