Kubernetes deploy arbitrary runtime object

main.go

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"strings"

	"github.com/pkg/errors"
	"github.com/spf13/cobra"

	"k8s.io/client-go/kubernetes/scheme"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
)

func main() error {
  config, err := ctrl.GetConfig()
  if err != nil {
    return errors.Wrap(err, "failed to get kubeconfig")
  }

  client, err := client.New(config, client.Options{})
  if err != nil {
    return errors.Wrap(err, "failed to create kubeclient")
  }

  // Assume `file` contains the output of Kustomization (i.e., multiple k8s resources in some desired order)
  allResources, err := ioutil.ReadFile(file)
  if err != nil {
    return errors.Wrap(err, "failed to read resources file")
  }

  resources := strings.Split(string(allResources), "---")

  errs := make([]error, 0)
  // resourceErrors := map[string]error{}
  for _, resource := range resources {
    // scheme should contain all of the types you want to use in your client.
    // this scheme is the default Kubernetes scheme with most core types.
    // to add custom types, do something like `customTypev1alpha1.AddToScheme(scheme)
    decode := scheme.Codecs.UniversalDeserializer().Decode
    obj, _, err := decode([]byte(resource), nil, nil)
	// TODO(ace): can switch here like this for type specific behavior: 
	// switch o := obj.(type) {
	// case *v1.Pod:
	// 	// o is a pod
	// case *v1beta1.Role:
	// 	// o is the actual role Object with all fields etc
	// case *v1beta1.RoleBinding:
	// case *v1beta1.ClusterRole:
	// case *v1beta1.ClusterRoleBinding:
	// case *v1.ServiceAccount:
	// default:
	// 	//o is unknown f
    if err != nil {
      errs = append(errs, err)
      // return err
    }
    _, err = controllerutil.CreateOrUpdate(context.Background(), client, obj, controllerutil.MutateFn(func() error { return nil })) // this func can mutate an object and return errors, etc
    if err != nil {
      errs = append(errs, err)
      // return errors.Wrap(err, "failed reconcile")
    }
  }
  if len(errs) == 1 {
    return errs[0]
  }
  if len(errs) > 1 {
  for _, err := range errs {
    fmt.Printf("ERROR: %s\n\n", errors.WithStack(err))
  }
  return errors.New("multiple errors deploying kubernetes objects")
 }