How does k8s cluster behave when accessed from its pod using kubectl? - jenkins

Question

I am working on a project with jenkins where I am already running the jenkins pod and want to run kubectl commands directly from the pod to connect with my host machine in order to do that I followed this SO question about k8s cluster remote access am on windows and have kubectl v1.23.3 installed on a jenkins pod I runned from my host machine k8s.
I managed to verify that running kubectl works properly on the jenkins pod (container):
kubectl create deployment nginx --image=nginx
kubectl create service nodeport nginx --tcp=80:80
when I ran kubectl get all from the jenkins container I get this output:
root#jenkins-64756886f7-2v92n:~/test# kubectl create deployment nginx --image=nginx
kubectl create service nodeport nginx --tcp=80:80
deployment.apps/nginx created
service/nginx created
root#jenkins-64756886f7-2v92n:~/test# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/jenkins-64756886f7-2v92n 1/1 Running 0 37m
pod/nginx-6799fc88d8-kxprv 1/1 Running 0 8s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/jenkins-service NodePort 10.110.105.78 <none> 8080:30090/TCP 39m
service/nginx NodePort 10.107.115.5 <none> 80:32355/TCP 8s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/jenkins 1/1 1 1 39m
deployment.apps/nginx 1/1 1 1 8s
NAME DESIRED CURRENT READY AGE
replicaset.apps/jenkins-64756886f7 1 1 1 37m
replicaset.apps/nginx-6799fc88d8 1 1 1 8s
root#jenkins-64756886f7-2v92n:~/test#
Initially I had Jenkins deployment attached to a namespace called devops-cicd
Tested the deployment on my browser and worked fine
and this is the output from my host machine:
PS C:\Users\affes> kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d9h
and when I specify the namespace I get the same result as from Jenkins container:
PS C:\Users\affes> kubectl get all -n devops-cicd
NAME READY STATUS RESTARTS AGE
pod/jenkins-64756886f7-2v92n 1/1 Running 0 38m
pod/nginx-6799fc88d8-kxprv 1/1 Running 0 93s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/jenkins-service NodePort 10.110.105.78 <none> 8080:30090/TCP 41m
service/nginx NodePort 10.107.115.5 <none> 80:32355/TCP 93s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/jenkins 1/1 1 1 41m
deployment.apps/nginx 1/1 1 1 93s
NAME DESIRED CURRENT READY AGE
replicaset.apps/jenkins-64756886f7 1 1 1 38m
replicaset.apps/nginx-6799fc88d8 1 1 1 93s
I don't know what's causing the resources created on that namespace directly without even specifying the namespace, and is there a possible way to configure something that will allow me to deploy on default namespace instead?
This is my deployment manifest:
apiVersion: apps/v1
kind: Deployment
metadata:
name: jenkins
namespace: devops-cicd
spec:
selector:
matchLabels:
app: jenkins
workload: cicd
replicas: 1
template:
metadata:
namespace: devops-cicd
labels:
app: jenkins
workload: cicd
spec:
containers:
- name: jenkins
image: jenkins/jenkins:lts
volumeMounts:
- name: dockersock
mountPath: "/var/run/docker.sock"
- name: docker
mountPath: "/usr/bin/docker"
securityContext:
privileged: true
runAsUser: 0 # Root
restartPolicy: Always
volumes:
- name: dockersock
hostPath:
path: /var/run/docker.sock
- name: docker
hostPath:
path: /usr/bin/docker
---
apiVersion: v1
kind: Service
metadata:
namespace: devops-cicd
name: jenkins-service
spec:
selector:
app: jenkins
workload: cicd
ports:
- name: http
port: 8080
nodePort: 30090
type: NodePort

Answer 1

You may have a different namespace configured by default in the kubectl in the Jenkins pod. You can check it with the following command.
kubectl config view | grep namespace
To change the default namespace to `default, you can run the following command.
kubectl config set-context --current --namespace=default
Please find more details here.