Parse K8s multi resource YAML manifest into client-go objects

k8s-multi-yaml-parser.go

package main

import (
        "fmt"
        "io/ioutil"
        "log"
        "net/http"
        "strings"

        appsv1 "k8s.io/api/apps/v1"
        corev1 "k8s.io/api/core/v1"
        "k8s.io/client-go/kubernetes/scheme"
)

//var manifestURL = "https://raw.githubusercontent.com/infracloudio/botkube/develop/deploy-all-in-one.yaml"
var manifestURL = "https://github.com/fission/fission/releases/download/1.12.0/fission-all-1.12.0.yaml"

func main() {
        resp, err := http.Get(manifestURL)
        if err != nil {
                log.Fatal(err)
        }
        defer resp.Body.Close()

        data, err := ioutil.ReadAll(resp.Body)
        if err != nil {
                log.Fatal(err)
        }

        manifests := string(data)
        fmt.Printf("Workloads:\n\n")
        decode := scheme.Codecs.UniversalDeserializer().Decode
        for _, spec := range strings.Split(manifests, "---") {
                if len(spec) == 0 {
                        continue
                }
                obj, _, err := decode([]byte(spec), nil, nil)
                if err != nil {
                        continue
                }
                switch obj.(type) {
                case *corev1.Pod:
                        pods := obj.(*corev1.Pod)
                        fmt.Println("Name:", pods.GetName())
                        fmt.Println("Namespace:", pods.GetNamespace())
                        fmt.Println("Kind:", pods.GetResourceVersion())
                        fmt.Println("---")

                case *appsv1.Deployment:
                        d := obj.(*appsv1.Deployment)
                        fmt.Println("Name:", d.GetName())
                        fmt.Println("Namespace:", d.GetNamespace())
                        fmt.Println("GVK:", d.GroupVersionKind())
                        fmt.Println("---")

                case *appsv1.StatefulSet:
                        ss := obj.(*appsv1.StatefulSet)
                        fmt.Println("Name:", ss.GetName())
                        fmt.Println("Namespace:", ss.GetNamespace())
                        fmt.Println("GVK:", ss.GroupVersionKind())
                        fmt.Println("---")

                case *appsv1.DaemonSet:
                        ds := obj.(*appsv1.DaemonSet)
                        fmt.Println("Name:", ds.GetName())
                        fmt.Println("Namespace:", ds.GetNamespace())
                        fmt.Println("GVK:", ds.GroupVersionKind())
                        fmt.Println("---")
                }
        }
}

This will break if --- is somewhere in a value.

For the ingresses:

import 	kubeyaml "k8s.io/apimachinery/pkg/util/yaml"

func ingressesFromFile(filepath string) ([]v1.Ingress, error) {
	var ingresses []v1.Ingress
	fileReader, err := os.Open(filepath)
	if err != nil {
		return ingresses, err
	}
	decode := kubeyaml.NewYAMLOrJSONDecoder(fileReader, 1024).Decode
	for {
		var ingress v1.Ingress
		err := decode(&ingress)
		if errors.Is(err, io.EOF) {
			return ingresses, nil
		}
		if err != nil {
			return ingresses, err
		}
		if ingress.Name != "" {
			ingresses = append(ingresses, ingress)
		}
	}
}