Warning: Rejected - All hosts are taken by other resources - kubernetes

I'm trying to setup Nginx-ingress controller to manage two paths on the same hostname in bare metal based cluster.
In the app1 namespace i have below nginx resource:-
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app1-ingress
namespace: app1
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app1
pathType: Prefix
backend:
service:
name: app1-service
port:
number: 80
And in the app2 namespace i have below nginx resource:-
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app2-ingress
namespace: app2
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app2
pathType: Prefix
backend:
service:
name: app2-service
port:
number: 80
My app1-service applied first and it is running fine, now when i applied the second app2-service it shows below warning and not able to access it on browser.
Annotations: <none>
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning Rejected 54s nginx-ingress-controller All hosts are taken by other resources
Warning Rejected 54s nginx-ingress-controller All hosts are taken by other resources
Warning Rejected 54s nginx-ingress-controller All hosts are taken by other resources
How do i configure my nginx ingress resource to connect multiple service paths on the same hostname?

Default Nginx Ingress controller doesn't support having different Ingress resources with the same hostname. You can have one Ingress resource that contains multiple paths, but in this case all apps should live in one namespace. Like this:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app1-ingress
namespace: app1
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app1
pathType: Prefix
backend:
service:
name: app1-service
port:
number: 80
- path: /app2
pathType: Prefix
backend:
service:
name: app2-service
port:
number: 80
Splitting ingresses between namespaces is currently not supported by standard Nginx Ingress controller.
You may however take a look at an alternative implementation of Nginx Ingress by Nginx Inc. They have support for Mergeable Ingresses.

Related

How to manage two paths on the same hostname?

I'm using Kubernetes v1.23.16 cluster (One master and three workers) bare metal based.
I have created couple of services in a separate namespace. The same as follows.
$ kubectl get services --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11d
app1 app1-service ClusterIP 10.103.151.235 <none> 80/TCP 19h
app2 app2-service ClusterIP 10.105.88.151 <none> 80/TCP 11d
kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 11d
Now I'm having below nginx resource yml to access the service outside. For example i would like access as given below.
http://web.example.com/app1
http://web.example.com/app2
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
name: app-ingress
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app1
pathType: Prefix
backend:
service:
name: app1-service
port:
number: 80
- path: /app2
pathType: Prefix
backend:
service:
name: app2-service
port:
number: 80
When i apply the nginx resource yml file it says service not found error.
$ kubectl describe ingress app-ingress
Name: app-ingress
Labels: <none>
Namespace: default
Address:
Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
Host Path Backends
---- ---- --------
web.example.com
/app1 app1-service:80 (<error: endpoints "app1-service" not found>)
/app2 app2-service:80 (<error: endpoints "app2-service" not found>)
Annotations: nginx.ingress.kubernetes.io/rewrite-target: /$2
Since my applications services are running in different namespace separately and my nginx resource yml is running in default namespace. So now how do i configure nginx resource file to access both of my service?
An Ingress resource can only refer to Services in the same namespace as the Ingress. To manage two paths on the same hostname that lead to backends in different namespaces, you will need two separate Ingress resources.
In the app1 namespace:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app-ingress
namespace: app1
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app1
pathType: Prefix
backend:
service:
name: app1-service
port:
number: 80
And in the app2 namespace:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app-ingress
namespace: app2
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app2
pathType: Prefix
backend:
service:
name: app2-service
port:
number: 80
With these resources in place, requests for http://web.example.com/app1 will go to app1-service, and requests for http://web.example.com/app2 will go to app2-service.
NB: I've removed your nginx.ingress.kubernetes.io/rewrite-target annotation because you're not doing any regex-based path rewriting in this example.
I've put a deployable example online here.
Just remove your rewrite path in single ingress you can achieve it.
If you are creating the multiple make sure to change the name as Larsks suggested else it will overwrite the existing one.
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: app-ingress
spec:
ingressClassName: nginx
rules:
- host: web.example.com
http:
paths:
- path: /app1
pathType: Prefix
backend:
service:
name: app1-service
port:
number: 80
- path: /app2
pathType: Prefix
backend:
service:
name: app2-service
port:
number: 80

Only allow requests to certain paths using k8s ingress

I've set up an ingress to route traffic to my http server, however I would like to leave some routes inaccessible from outside of the cluster.
Example routes:
/status -> end point to determine service status
/users/names -> returns users
/users/ages -> returns ages
current ingress:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
namespace: my-namespace
name: my-app-ingress
annotations:
kubernetes.io/ingress.class: nginx
spec:
rules:
- host: localhost
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: my-service
port:
number: 8080
this works currently but leaves all routes accessible. What I want to do is only have routes that fall under the /users path open, so that would be both /users/names and /users/ages. That would leave /status inaccessible from outside of the cluster. Is this achievable from changing the ingress configuration? Any help would be appreciated.
Just specify the path that you want to expose via the ingress like this:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
namespace: my-namespace
name: my-app-ingress
annotations:
kubernetes.io/ingress.class: nginx
spec:
rules:
- host: localhost
http:
paths:
- pathType: Prefix
path: /users # <- add the path here
backend:
service:
name: my-service
port:
number: 8080

Creating ingress resource

How do I create an ingress(ping) to expose a single service(hello) given a path (/hello )and a port (6789) in a given namespace (dev)?
the following is right? Also how to verify the same?
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ping
namespace: dev
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- http:
paths:
- path: /hello
pathType: Prefix
backend:
service:
name: hello
port:
number: 6789
You might need to add the host into the ingress YAML if you are looking forward to use the domain for resolution like
hello-world.info forward the traffic to hello service.
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: example-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
rules:
- host: hello-world.info
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 8080
to verify the changes you can use the Curl to check and test the endpoint also.
Once your YAML file is applied and ingress is created on cluster you can hit the endpoint and verify.
i would recommend checking out the part test your ingress :
https://kubernetes.io/docs/tasks/access-application-cluster/ingress-minikube/#test-your-ingress

Is it possible to use same hostname with multiple Ingress resources running in different namespaces?

I want to use the same hostname let's say example.com with multiple Ingress resources running in different namespaces i.e monitoring and myapp. I'm using Kubernetes nginx-ingress controller.
haproxy-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: haproxy-ingress
namespace: myapp
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
tls:
- hosts:
# fill in host here
- example.com
rules:
- host: example.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: haproxy
port:
number: 80
grafana-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: grafana-ingress
namespace: monitoring
annotations:
nginx.ingress.kubernetes.io/use-regex: "true"
spec:
tls:
- hosts:
- example.com
rules:
- host: example.com
http:
paths:
# only match /grafana and paths under /grafana/
- path: /grafana(/|$)(.*)
pathType: Prefix
backend:
service:
name: grafana
port:
number: 3000
When I'm doing curl example.com then it is redirecting me to the deployment running in namespace one(as expected) but when I'm doing curl example.com/grafana then still it is redirecting me to namespace one deployment.
Please help.
Yes it is possible.
There can be two issues in your case.
One is you don't need the regex path for grafana ingress. Simple /grafana path will be fine with path type Prefix as with path type Prefix any /grafana/... will be redirected associated service. So the manifest file will be:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: grafana-ingress
namespace: monitoring
spec:
tls:
- hosts:
- example.com
rules:
- host: example.com
http:
paths:
- path: /grafana
pathType: Prefix
backend:
service:
name: grafana
port:
number: 3000
And the second issue can be the related service or deployment might not be the under same namespace monitoring. Please make sure the deployment/service/secret or other resources needed for grafana remains under the same namespace monitoring.

ingress can not get the default http backend

The ingress I config to run with the controller ingress-nginx.
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: app-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
tls:
- hosts:
- XXX.XX.com
secretName: app-tls
rules:
- host: XXX.XX.com
http:
paths:
- path: /my-api(/|$)(.*)
backend:
serviceName: app
servicePort: 80
---
apiVersion: v1
kind: Service
metadata:
name: my-api
spec:
selector:
app: my-api
ports:
- name: app
port: 3000
targetPort: 3000
I can run the api locally curl localIP:3000/testapi, but it can not run remotely.
# kubectl describe ingress app-ingress
Name: app-ingress
Namespace: default
Address: XX.XX.XX.XX
Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
TLS:
app-tls terminates www.daichenchen.cn
Rules:
Host Path Backends
---- ---- --------
XXX.XX.com
/my-api(/|$)(.*) app:80 (<error: endpoints "app" not found>)
I already succeed install the ingress-nginx and all the pod work without error.
Your defined serviceName in Ingress rules and Service should be same.
Like this :
...
rules:
- host: XXX.XX.com
http:
paths:
- path: /my-api(/|$)(.*)
backend:
serviceName: app
servicePort: 80
apiVersion: v1
kind: Service
metadata:
name: app
spec:
selector:
app: my-api
ports:
- name: app
port: 3000
targetPort: 3000
If Ingress and the Service is in different namespace, you can also add the service name to the ingress rule. In this case you need to use dns name for service <service-name>.<namespace>.
For example:
rules:
- host: example.com
http:
paths:
- path: /my-api
backend:
serviceName: test-service.test-namespace
servicePort: 80
apiVersion: v1
kind: Service
metadata:
name: test-service
namespace: test-namespace
The way ingress controller finds out Endpoints of a service is it searches for a kubernetes service with the serviceName provided in the ingress resource in the namespace where you have created the ingress resource. If there is no kubernetes service with serviceName found you get endpoints not found.
The Endpoints of the service contains the IPs of pods behind the kubernetes service.
So in your case either the kubernetes service does not exist or it's in a different namespace than where ingress resource is created.
Some variant of nginx ingress controller does not support default backend and for this it's expected to have the error: endpoints "default-http-backend" not found
Another variant of nginx ingress controller supports default backend.
Double check which variant of nginx ingress controller you installed