Add kyaml command for invoking container filters

kyaml/runfn/runfn.go

@@ -0,0 +1,98 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package runfn
+
+import (
+	"io"
+	"path/filepath"
+
+	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/kio/filters"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// RunFns runs the set of configuration functions in a local directory against
+// the Resources in that directory
+type RunFns struct {
+	// Path is the path to the directory containing functions
+	Path string
+
+	// FunctionPaths Paths allows functions to be specified outside the configuration
+	// directory
+	FunctionPaths []string
+
+	// Output can be set to write the result to Output rather than back to the directory
+	Output io.Writer
+
+	// containerFilterProvider may be override by tests to fake invoking containers
+	containerFilterProvider func(string, string, *yaml.RNode) kio.Filter
+}
+
+// Execute runs the command
+func (r RunFns) Execute() error {
+	// make the path absolute so it works on mac
+	var err error
+	r.Path, err = filepath.Abs(r.Path)
+	if err != nil {
+		return errors.Wrap(err)
+	}
+
+	// default the containerFilterProvider if it hasn't been override.  Split out for testing.
+	(&r).init()
+
+	// identify the configuration functions in the directory
+	buff := &kio.PackageBuffer{}
+	err = kio.Pipeline{
+		Inputs:  []kio.Reader{kio.LocalPackageReader{PackagePath: r.Path}},
+		Filters: []kio.Filter{&filters.IsReconcilerFilter{}},
+		Outputs: []kio.Writer{buff},
+	}.Execute()
+	if err != nil {
+		return err
+	}
+
+	// accept a
+	for i := range r.FunctionPaths {
+		err := kio.Pipeline{
+			Inputs:  []kio.Reader{kio.LocalPackageReader{PackagePath: r.FunctionPaths[i]}},
+			Outputs: []kio.Writer{buff},
+		}.Execute()
+		if err != nil {
+			return err
+		}
+	}
+
+	// reconcile each local API
+	var fltrs []kio.Filter
+	for i := range buff.Nodes {
+		api := buff.Nodes[i]
+		img, path := filters.GetContainerName(api)
+		fltrs = append(fltrs, r.containerFilterProvider(img, path, api))
+	}
+
+	pkgIO := &kio.LocalPackageReadWriter{PackagePath: r.Path}
+	inputs := []kio.Reader{pkgIO}
+	var outputs []kio.Writer
+	if r.Output == nil {
+		// write back to the package
+		outputs = append(outputs, pkgIO)
+	} else {
+		// write to the output instead of the directory
+		outputs = append(outputs, kio.ByteWriter{Writer: r.Output})
+	}
+	return kio.Pipeline{Inputs: inputs, Filters: fltrs, Outputs: outputs}.Execute()
+}
+
+// init initializes the RunFns with a containerFilterProvider.
+func (r *RunFns) init() {
+	// if containerFilterProvider hasn't been set, use the default
+	if r.containerFilterProvider == nil {
+		r.containerFilterProvider = func(image, path string, api *yaml.RNode) kio.Filter {
+			cf := &filters.ContainerFilter{Image: image, Config: api}
+			cf.SetMountPath(filepath.Join(r.Path, path))
+			return cf
+		}
+	}
+}