Trying to figure out how to use client-go for oc and kubectl...

oc-dummy-go.go

package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	// "time"

	// "k8s.io/client-go/rest"
	// "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
)

func main() {
	var kubeconfig *string
	if home := os.Getenv("HOME"); home != "" {
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	} else {
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	}
	flag.Parse()

	// use the current context in kubeconfig
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil {
		panic(err.Error())
	}

	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}

	// pods, err := clientset.CoreV1().Pods("").List(metav1.ListOptions{})
	// if err != nil {
		// panic(err.Error())
	// }
	// fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))

	namespace := "memcached-operator-external"

	deployments, err := clientset.AppsV1().Deployments(namespace).List(metav1.ListOptions{})
	if err != nil {
		panic(err.Error())
	}

	fmt.Printf("There are %d deployments in the namespace %s\n", len(deployments.Items), namespace)

	// The _ is silently assigned to the index (range returns index,item)
	for _, deployment := range deployments.Items {
		// This is kinda cool...
		// fmt.Printf("Deployment OwnerReference%v \n", deployment.GetOwnerReferences())

		// Print name and namespace
		fmt.Printf("Deployment Namespace/Name: %v/%v \n", deployment.GetObjectMeta().GetNamespace(), deployment.GetObjectMeta().GetName())



		// Why does this return a giant number: 824637082989
		// Should be 1...
		// EDIT FOR THOSE WHO COME AFTER:  deployment.Spec.Replicas is a POINTER
		// See the off-hand comment in the docs here:
		// https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#deploymentspec-v1-app
		fmt.Printf("Deployment spec.replicas: %d \n", deployment.Spec.Replicas)
		// So, this line should be:
		// fmt.Printf("Deployment spec.replicas: %d \n", *(deployment.Spec.Replicas))
		
		// Why does this return 824633986528, should be 600...
		// EDIT: Same as above - this is a pointer (not documented in the docs linked above...)
		fmt.Printf("Deployment spec.progressDeadlineSeconds: %d \n", deployment.Spec.ProgressDeadlineSeconds)
		// Should be ... *(deployment.Spec.ProgressDeadlineSeconds))
		
		
		// These two return correct values...
		fmt.Printf("Deployment Status.Replicas: %d \n", deployment.Status.Replicas)
		fmt.Printf("Deployment Status.AvailableReplicas: %d \n", deployment.Status.AvailableReplicas)

		// fmt.Printf("Deployment spec: %v \n", deployment.Spec)


	}

	
	// DeploymentLists are made up of deployemnt objects
	// Deployment objects are made up of, among other things, deploymentSpec objects
	// DeploymentSpec objects have actual values, maybe.  I get weird values from them sometimes.
	// Sheesh

}

oc_cli_output.txt

# Output of the command: $ oc get deployment memcached-cluster-1 -o yaml
#
#
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2019-07-30T14:58:13Z"
  generation: 1
  name: memcached-cluster-1
  namespace: memcached-operator-external
  ownerReferences:
  - apiVersion: cache.example.com/v1alpha1
    blockOwnerDeletion: true
    controller: true
    kind: Memcached
    name: memcached-cluster-1
    uid: 7428005f-b2da-11e9-8deb-5254008c19b7
  resourceVersion: "432448"
  selfLink: /apis/extensions/v1beta1/namespaces/memcached-operator-external/deployments/memcached-cluster-1
  uid: 7429b444-b2da-11e9-8deb-5254008c19b7
spec:
  progressDeadlineSeconds: 600
  replicas: 3
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: memcached
      memcached_cr: memcached-cluster-1
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: memcached
        memcached_cr: memcached-cluster-1
    spec:
      containers:
      - command:
        - memcached
        - -m=64
        - -o
        - modern
        - -v
        image: memcached:1.4.36-alpine
        imagePullPolicy: IfNotPresent
        name: memcached
        ports:
        - containerPort: 11211
          name: memcached
          protocol: TCP
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 3
  conditions:
  - lastTransitionTime: "2019-07-30T14:58:13Z"
    lastUpdateTime: "2019-07-30T14:58:18Z"
    message: ReplicaSet "memcached-cluster-1-68444bb64f" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  - lastTransitionTime: "2019-08-12T17:45:15Z"
    lastUpdateTime: "2019-08-12T17:45:15Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  observedGeneration: 1
  readyReplicas: 3
  replicas: 3
  updatedReplicas: 3

output.txt

$ go run oc-dummy-go.go 
There are 1 deployments in the namespace memcached-operator-external
Deployment Namespace/Name: memcached-operator-external/memcached-cluster-1 
Deployment spec.replicas: 824633989260 
Deployment spec.progressDeadlineSeconds: 824633989600 
Deployment Status.Replicas: 3 
Deployment Status.AvailableReplicas: 3 

# Why are the values from "deployment.Spec.ProgressDeadlineSeconds" and "deployment.Spec.Replicas",
# line 67 and 73 of oc-dummy-go.go, returning huge numbers?  Results *should* be 600, and 3, respectively.
# See lines 24 and 25 of oc_cli_output.txt...

# EDIT FOR THOSE WHO COME AFTER:  the items on 67 and 73 are pointers, and I didn't realize it.  They need to be referred to as such, with the `*(thing)` notation...