Exec function implementation

kyaml/fn/runtime/exec/exec.go

@@ -0,0 +1,34 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package exec
+
+import (
+	"io"
+	"os/exec"
+
+	"sigs.k8s.io/kustomize/kyaml/fn/runtime/runtimeutil"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+type Filter struct {
+	// Path is the path to the executable to run
+	Path string `yaml:"path,omitempty"`
+
+	// Args are the arguments to the executable
+	Args []string `yaml:"args,omitempty"`
+
+	runtimeutil.FunctionFilter
+}
+
+func (c *Filter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
+	c.FunctionFilter.Run = c.Run
+	return c.FunctionFilter.Filter(nodes)
+}
+
+func (c *Filter) Run(reader io.Reader, writer io.Writer) error {
+	cmd := exec.Command(c.Path, c.Args...)
+	cmd.Stdin = reader
+	cmd.Stdout = writer
+	return cmd.Run()
+}