Kubernetes nginx ingress controller as loadbalancer gets random ports - nginx

I'm trying to expose kubernetes dashboard publicly via an ingress on a single master bare-metal cluster. The issue is that the LoadBalancer (nginx ingress controller) service I'm using is not opening the 80/443 ports which I would expect it to open/use. Instead it takes some random ports from the 30-32k range. I know I can set this range with --service-node-port-range but I'm quite certain I didn't have to do this a year ago on another server. Am I missing something here?
Currently this is my stack/setup (clean install of Ubuntu 16.04):
Nginx Ingress Controller (installed via helm)
MetalLB
Kubernetes Dashboard
Kubernetes Dashboard Ingress to deploy it publicly on <domain>
Cert-Manager (installed via helm)
k8s-dashboard-ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
# add an annotation indicating the issuer to use.
cert-manager.io/cluster-issuer: letsencrypt-staging
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/ssl-redirect: "true"
nginx.ingress.kubernetes.io/secure-backends: "true"
nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
name: kubernetes-dashboard-ingress
namespace: kubernetes-dashboard
spec:
rules:
- host: <domain>
http:
paths:
- backend:
serviceName: kubernetes-dashboard
servicePort: 443
path: /
tls:
- hosts:
- <domain>
secretName: kubernetes-dashboard-staging-cert
This is what my kubectl get svc -A looks like:
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
cert-manager cert-manager ClusterIP 10.101.142.87 <none> 9402/TCP 23h
cert-manager cert-manager-webhook ClusterIP 10.104.104.232 <none> 443/TCP 23h
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 6d6h
ingress-nginx nginx-ingress-controller LoadBalancer 10.100.64.210 10.65.106.240 80:31122/TCP,443:32697/TCP 16m
ingress-nginx nginx-ingress-default-backend ClusterIP 10.111.73.136 <none> 80/TCP 16m
kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 6d6h
kubernetes-dashboard cm-acme-http-solver-kw8zn NodePort 10.107.15.18 <none> 8089:30074/TCP 140m
kubernetes-dashboard dashboard-metrics-scraper ClusterIP 10.96.228.215 <none> 8000/TCP 5d18h
kubernetes-dashboard kubernetes-dashboard ClusterIP 10.99.250.49 <none> 443/TCP 4d6h
Here are some more examples of what's happening:
curl -D- http://<public_ip>:31122 -H 'Host: <domain>'
returns 308, as the protocol is http not https. This is expected
curl -D- http://<public_ip> -H 'Host: <domain>'
curl: (7) Failed to connect to <public_ip> port 80: Connection refused
port 80 is closed
curl -D- --insecure https://10.65.106.240 -H "Host: <domain>"
reaching the dashboard through an internal IP obviously works and I get the correct k8s-dashboard html.
--insecure is due to the let's encrypt not working yet as the acme challenge on port 80 is unreachable.
So to recap, how do I get 2. working? E.g. reaching the service through 80/443?
EDIT: Nginx Ingress Controller .yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2020-02-12T20:20:45Z"
labels:
app: nginx-ingress
chart: nginx-ingress-1.30.1
component: controller
heritage: Helm
release: nginx-ingress
name: nginx-ingress-controller
namespace: ingress-nginx
resourceVersion: "1785264"
selfLink: /api/v1/namespaces/ingress-nginx/services/nginx-ingress-controller
uid: b3ce0ff2-ad3e-46f7-bb02-4dc45c1e3a62
spec:
clusterIP: 10.100.64.210
externalTrafficPolicy: Cluster
ports:
- name: http
nodePort: 31122
port: 80
protocol: TCP
targetPort: http
- name: https
nodePort: 32697
port: 443
protocol: TCP
targetPort: https
selector:
app: nginx-ingress
component: controller
release: nginx-ingress
sessionAffinity: None
type: LoadBalancer
status:
loadBalancer:
ingress:
- ip: 10.65.106.240
EDIT 2: metallb configmap yaml
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 10.65.106.240-10.65.106.250

So, to solve the 2nd question, as I suggested, you can use hostNetwork: true parameter to map container port to the host it is running on. Note that this is not a recommended practice, and you should always avoid to do this, unless you have a reason.
Example:
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: nginx
spec:
hostNetwork: true
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
hostPort: 80 # this parameter is optional, but recommended when using host network
name: nginx
When I deploy this yaml, I can check where the pod is running and curl that host's port 80.
root#v1-16-master:~# kubectl get po -owide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx 1/1 Running 0 105s 10.132.0.50 v1-16-worker-2 <none> <none>
Note: now I know the pod is running on worker node 2. I just need its IP address.
root#v1-16-master:~# kubectl get no -owide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
v1-16-master Ready master 52d v1.16.4 10.132.0.48 xxxx Ubuntu 16.04.6 LTS 4.15.0-1052-gcp docker://19.3.5
v1-16-worker-1 Ready <none> 52d v1.16.4 10.132.0.49 xxxx Ubuntu 16.04.6 LTS 4.15.0-1052-gcp docker://19.3.5
v1-16-worker-2 Ready <none> 52d v1.16.4 10.132.0.50 xxxx Ubuntu 16.04.6 LTS 4.15.0-1052-gcp docker://19.3.5
v1-16-worker-3 Ready <none> 20d v1.16.4 10.132.0.51 xxxx Ubuntu 16.04.6 LTS 4.15.0-1052-gcp docker://19.3.5
root#v1-16-master:~# curl 10.132.0.50 2>/dev/null | grep title
<title>Welcome to nginx!</title>
root#v1-16-master:~# kubectl delete po nginx
pod "nginx" deleted
root#v1-16-master:~# curl 10.132.0.50
curl: (7) Failed to connect to 10.132.0.50 port 80: Connection refused
And of course it also works if I go to the public IP on my browser.

update:
i didn't see the edit part of the question when I was writing this answer. it doesn't make sense given the additional info provided. please disregard.
original:
apparently the cluster you are using now has its ingress controller setup over a node-port type service instead of a load-balancer. in order to get desired behavior you need to change configuration of ingress-controller. refer to nginx ingress controller documentation for metalLB cases how to do this.

Related

How to access simple nginx deployment on kubernetes?

I want to deploy a simple nginx app on my own kubernetes cluster.
I used the basic nginx deployment. On the machine with the ip 192.168.188.10. It is part of cluster of 3 raspberries.
NAME STATUS ROLES AGE VERSION
master-pi4 Ready master 2d20h v1.18.2
node1-pi4 Ready <none> 2d19h v1.18.2
node2-pi3 Ready <none> 2d19h v1.18.2
$ kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
$ kubectl create service nodeport nginx --tcp=80:80
service/nginx created
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
my-nginx-8fb6d868-6957j 1/1 Running 0 10m
my-nginx-8fb6d868-8c59b 1/1 Running 0 10m
nginx-f89759699-n6f79 1/1 Running 0 4m20s
$ kubectl describe service nginx
Name: nginx
Namespace: default
Labels: app=nginx
Annotations: <none>
Selector: app=nginx
Type: NodePort
IP: 10.98.41.205
Port: 80-80 80/TCP
TargetPort: 80/TCP
NodePort: 80-80 31400/TCP
Endpoints: <none>
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
But I always get a time out
$ curl http://192.168.188.10:31400/
curl: (7) Failed to connect to 192.168.188.10 port 31400: Connection timed out
Why is the web server nginx not reachable? I tried to run it from the same machine I deployed it to? How can I make it accessible from an other machine from the network on port 31400?
As mentioned by #suren, you are creating a stand-alone service without any link with your deployment.
You can solve using the command from suren answer, or creating a new deployment using the follow yaml spec:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- name: http
containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx-svc
spec:
type: NodePort
selector:
app: nginx
ports:
- protocol: TCP
port: 80
targetPort: 80
After, type kubectl get svc to get the nodeport to access your service.
nginx-svc NodePort 10.100.136.135 <none> 80:31816/TCP 34s
To access use http://<YOUR_NODE_IP>:31816
so is 192.168.188.10 your host ip / your vm ip ?
you have to check it first if any service using that port or maybe you haven't add it into your security group if you using cloud platform.
just to make sure you can create a pod and access it using fqdn like my-svc.my-namespace.svc.cluster-domain.example

Kubernetes, access IP outside the cluster

I have a corporate network(10.22..) which hosts a Kubernetes cluster(10.225.0.1). How can I access some VM in the same network but outside the cluster from within the pod in the cluster?
For example, I have a VM with IP 10.22.0.1:30000, which I need to access from a Pod in Kubernetes cluster. I tried to create a Service like this
apiVersion: v1
kind: Service
metadata:
name: vm-ip
spec:
selector:
app: vm-ip
ports:
- name: vm
protocol: TCP
port: 30000
targetPort: 30000
externalIPs:
- 10.22.0.1
But when I do "curl http://vm-ip:30000" from a Pod(kubectl exec -it), it returns "connection refused" error. But it works with "google.com". What are the ways of accessing the external IPs?
You can create an endpoint for that.
Let's go through an example:
In this example, I have a http server on my network with IP 10.128.15.209 and I want it to be accessible from my pods inside my Kubernetes Cluster.
First thing is to create an endpoint. This is going to let me create a service pointing to this endpoint that will redirect the traffic to my external http server.
My endpoint manifest is looking like this:
apiVersion: v1
kind: Endpoints
metadata:
name: http-server
subsets:
- addresses:
- ip: 10.128.15.209
ports:
- port: 80
$ kubectl apply -f http-server-endpoint.yaml
endpoints/http-server configured
Let's create our service:
apiVersion: v1
kind: Service
metadata:
name: http-server
spec:
ports:
- port: 80
targetPort: 80
$ kubectl apply -f http-server-service.yaml
service/http-server created
Checking if our service exists and save it's clusterIP for letter usage:
user#minikube-server:~$$ kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
http-server ClusterIP 10.96.228.220 <none> 80/TCP 30m
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 10d
Now it's time to verify if we can access our service from a pod:
$ kubectl run ubuntu -it --rm=true --restart=Never --image=ubuntu bash
This command will create and open a bash session inside a ubuntu pod.
In my case I'll install curl to be able to check if I can access my http server. You may need install mysql:
root#ubuntu:/# apt update; apt install -y curl
Checking connectivity with my service using clusterIP:
root#ubuntu:/# curl 10.128.15.209:80
Hello World!
And finally using the service name (DNS):
root#ubuntu:/# curl http-server
Hello World!
So, in your specific case you have to create this:
apiVersion: v1
kind: Endpoints
metadata:
name: vm-server
subsets:
- addresses:
- ip: 10.22.0.1
ports:
- port: 30000
---
apiVersion: v1
kind: Service
metadata:
name: vm-server
spec:
ports:
- port: 30000
targetPort: 30000

minikube service --url when service exposes multiple ports

My my-app service exposes multiple ports:
/Mugen$ kubectl get endpoints
NAME ENDPOINTS AGE
my-app 172.17.0.7:80,172.17.0.7:8003,172.17.0.7:8001 + 3 more... 7m
kubernetes 192.168.99.100:8443 10h
mysql-server 172.17.0.5:3306 10h
When executing minikube service my-app -n default --url, I'm getting each port forwarded by minikube, however I can't tell which is which without querying them. Is there a simple way to print the mapping or to set the port forwarding myself?
/Mugen$ minikube service my-app -n default --url
http://192.168.99.100:30426
http://192.168.99.100:30467
http://192.168.99.100:31922
http://192.168.99.100:32008
http://192.168.99.100:30895
http://192.168.99.100:31602
You can easily check the port and TargetPort mapping in kubernetes service using:
kubectl descrive svc my-app
Name: my-app
Namespace: default
Labels: <none>
Annotations: <none>
Selector: app=MyApp
Type: NodePort
IP: 10.152.183.56
Port: http 80/TCP
TargetPort: 9376/TCP
NodePort: http 30696/TCP
Endpoints: <none>
Port: https 443/TCP
TargetPort: 9377/TCP
NodePort: https 32715/TCP
Endpoints: <none>
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
This way you can find port, targetport and endpoints mapping.

Kubernetes services cannot reach each other anymore

I’m running Kubernetes on GKE, this was working before but about 2 days ago something changed. I don’t think I changed anything to my configuration. My services do not seem to work anymore. None of my services can talk to each other. When SSHing into a running pod I cannot ping them via their service name but also not via their internal IP addresses. The external IP of the load balancer is not approachable. Here is an example of how I define the deployment:
apiVersion: apps/v1beta1
kind: Deployment
metadata:
labels:
ksonnet.io/component: app-name
name: app-name
spec:
replicas: 1
template:
metadata:
labels:
app: app-name
And here the service:
apiVersion: v1
kind: Service
metadata:
labels:
ksonnet.io/component: app-name
name: app-name
spec:
loadBalancerIP: x.x.x.x
ports:
- port: 4999
targetPort: 5000
selector:
app: app-name
type: LoadBalancer
I am fairly new to Kubernetes and networking and I have no clue where to look or how to debug this issue.
EDIT:
Here are the relevant kubectl get services -n test
dashboard ClusterIP 10.47.242.176 <none> 5000/TCP 1h
app-name LoadBalancer 10.47.246.63 x.xxx.xx.xx 4999:31439/TCP 1h
Then here is the kubectl describe service app-name -n test
Name: app-name
Namespace: test
Labels: app.kubernetes.io/deploy-manager=ksonnet
ksonnet.io/component=app-name
Annotations: ksonnet.io/managed: {pristine...}
Selector: app=app-name
Type: LoadBalancer
IP: 10.47.246.63
IP: xx.xxx.xx.x
LoadBalancer Ingress: xx.xxx.xx.x
Port: <unset> 4999/TCP
TargetPort: 5000/TCP
NodePort: <unset> 31439/TCP
Endpoints: 10.44.1.141:5000
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
EDIT 2: I tried the curl command on the default port and it timed out:
curl: (7) Failed to connect to app-name port 80: Connection timed out
When trying it on the full endpoint it got a connection refused:
curl: (7) Failed to connect to app-name port 4999: Connection refused
When looking at the deployment I get the following pod template:
Pod Template:
Labels: app=app-name
Containers:
model-manager:
Image: gcr.io/ns-delay/app-name:0.1
Port: 5000/TCP
Host Port: 0/TCP
As i see your selector in service is not matching the labels in Deployment , change to
metadata:
labels:
app: app-name
in your Deployment and it should work then.

Fail to expose my pod to the internet

I have tried some example to run a specific image on my kubernetes cluster, I did this command:
kubectl run my-nginx --image=nginx --replicas=2 --port=80
then:
kubectl expose rc my-nginx --port=80 --type=LoadBalancer
and when I go:
kubectl get service
I get:
NAME LABELS SELECTOR IP(S) PORT(S)
kubernetes component=apiserver,provider=kubernetes <none> 10.0.0.1 443/TCP
my-nginx run=my-nginx run=my-nginx 10.0.100.19 80/TCP
now, I have a cluster that I created with my kubernetes, and onw I want to put something in my browser and see the landing page of nginx...
I tried to put my master machine ip with port 80 in the end and it didnt work, what should I do?
thanks!!
describe svc:
Name: my-nginx
Namespace: default
Labels: run=my-nginx
Selector: run=my-nginx
Type: LoadBalancer
IP: x.x.xxx.xx
LoadBalancer Ingress: dasfasdgfgaasok23o4j34ij4ofa69da-1772099277.us-west-2.elb.amazonaws.com
Port: <unnamed> 80/TCP
NodePort: <unnamed> 31331/TCP
Endpoints: x.x.xxx.x:80,xx.xxx.x.x:80
Session Affinity: None
No events.

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