I created a small java application launching manually a jetty server listening to the address 127.0.0.1 port 8081.
The small server app listens for GET requests to the subaddress /dockerClient/ping, and answers "pong".
I test with SoapUI on http://127.0.0.1:8081/dockerClient/ping, and I get my pong.
I create a docker image, deploy the application on minikube and expose a service with the following configuration:
apiVersion: apps/v1
kind: Deployment
metadata:
name: client
labels:
tier: frontend
spec:
replicas: 1
selector:
matchLabels:
tier: frontend
template:
metadata:
labels:
tier: frontend
spec:
containers:
- name: docker-client
image: docker-client
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8081
---
apiVersion: v1
kind: Service
metadata:
name: client-service
labels:
tier: frontend
spec:
type: NodePort
ports:
- port: 8081
protocol: TCP
name: http
selector:
tier: frontend
Once I deploy and expose, I get the following information:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
client-service NodePort 10.107.64.238 <none> 8081:31703/TCP 19m
I try to use SoapUI to reach the service :
For this, I retrieve the IP of the minikube using :
echo $(minikupe ip)
Then, I try a GET request to http://$(minikube ip):31703/dockerClient/ping, but the request is refused.
I tried on http://$(minikube ip):8081/dockerClient/ping, same.
What do I do wrong? How can I reach the jetty server exposing my ping?
In your service yml, you just tell the port (it can only be used within the cluster), it is not enough to expose your service outside your minikube, you also need to specify the targetPort (should match the container port e.g.8081) and nodePort (it is the port you can ping from localhost e.g. 31081).
---
apiVersion: v1
kind: Service
metadata:
name: client-service
labels:
tier: frontend
spec:
type: NodePort
ports:
- port: 8081 # access within the cluster
targetPort: 8081 # should match to the container port
nodePort: 31081 # expose outside the cluster and range from 30000 to 32767
protocol: TCP
name: http
selector:
tier: frontend
After you added the targetPort and nodePort, you can get the public endpoint by:
minikube service client-service --url
P.S. nodePort is optional, minikube would assign an random port from the range if nodePort has not been specified.
I think the jetty server should listen to the address 0.0.0.0.
Related
I have a running pod that was created with the following pod-definition.yaml:
apiVersion: v1
kind: Pod
metadata:
name: microservice-one-pod-name
labels:
app: microservice-one-app-label
type: front-end
spec:
containers:
- name: microservice-one
image: vismarkjuarez1994/microserviceone
ports:
- containerPort: 2019
I then created a Service using the following service-definition.yaml:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 30008
targetPort: 2019
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
I then ran kubectl describe node minikube to find the Node IP I should be connecting to -- which yielded:
Addresses:
InternalIP: 192.168.49.2
Hostname: minikube
But I get no response when I run the following curl command:
curl 192.168.49.2:30008
The request also times out when I try to access 192.168.49.2:30008 from a browser.
The pod logs show that the container is up and running. Why can't I access my Service?
The problem is that you are trying to access your service at the port parameter which is the internal port at which the service will be exposed, even when using NodePort type.
The parameter you were searching is called nodePort, which can optionally be specified together with port and targetPort. Quoting the documentation:
By default and for convenience, the Kubernetes control plane will
allocate a port from a range (default: 30000-32767)
Since you didn't specify the nodePort, one in the range was automatically picked up. You can check which one by:
kubectl get svc -owide
And then access your service externally at that port.
As an alternative, you can change your service definition to be something like:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 30008
targetPort: 2019
nodePort: 30008
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
But take in mind that you may need to delete your service and create it again in order to change the nodePort allocated.
I think you missed the Port in your service:
apiVersion: v1
kind: Pod
metadata:
name: microservice-one-pod-name
labels:
app: microservice-one-app-label
type: front-end
spec:
containers:
- name: microservice-one
image: vismarkjuarez1994/microserviceone
ports:
- containerPort: 2019
and your service should be like this:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 2019
targetPort: 2019
nodePort: 30008
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
You can access to your app after enabling the Minikube ingress if you want trying Ingress with Minikube.
minikube addons enable ingress
I've got this webserver config:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: webserver
spec:
replicas: 1
template:
metadata:
labels:
app: webserver
spec:
containers:
- name: webserver
image: nginx:alpine
ports:
- containerPort: 80
volumeMounts:
- name: hostvol
mountPath: /usr/share/nginx/html
volumes:
- name: hostvol
hostPath:
path: /home/docker/vol
and this web service config:
apiVersion: v1
kind: Service
metadata:
name: web-service
labels:
run: web-service
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
protocol: TCP
selector:
app: webserver
I was expecting to be able to connect to the webserver via http://192.168.99.100:80 with this config but Chrome gives me a ERR_CONNECTION_REFUSED.
I tried minikube service --url web-service which gives http://192.168.99.100:30276 however this also has a ERR_CONNECTION_REFUSED.
Any further suggestions?
UPDATE
I updated the port / targetPort to 80.
However, I now get:
ERR_CONNECTION_REFUSED for http://192.168.99.100:80/
and
an nginx 403 for http://192.168.99.100:31540/
In your service, you can define a nodePort
apiVersion: v1
kind: Service
metadata:
name: web-service
labels:
run: web-service
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
nodePort: 32700
protocol: TCP
selector:
app: webserver
Now, you will be able to access it on http://:32700
Be careful with port 80. Ideally, you would have an nginx ingress controller running on port 80 and all traffic will be routed through it. Using port 80 as nodePort will mess up your deployment.
In your service, you did not specify a targetPort, so the service is using the port value as targetPort, however your container is listening on 80. Add a targetPort: 80 to the service.
NodePort port range varies from 30000-32767(default). When you expose a service without specifying a port, kubernetes picks up a random port from the above range and provide you.
You can check the port by typing the below command
kubectl get svc
In your case - the application is port forwarded to 31540. Your issues seems to be the niginx configuration. Check for the nginx logs.
Please check permissions of mounted volume /home/docker/vol
To fix this you have to make the mounted directory and its contents publicly readable:
chmod -R o+rX /home/docker/vol
I have a service and deployment kube config files like below.
Now, when i apply these two files, its creating a loadbalancer but its targeting to a random port but not port 80.
I'm a newbie to EKS and tried different kube config files but it still tries to target a random port.
service file:
apiVersion: v1
kind: Service
metadata:
name: runners-test
labels:
app: runners-test
spec:
ports:
- port: 80
targetPort: 80
selector:
app: runners-test
type: LoadBalancer
deployment file:
apiVersion: apps/v1
kind: Deployment
metadata:
name: runners-test
labels:
app: runners-test
spec:
replicas: 1
selector:
matchLabels:
app: runners-test
template:
metadata:
labels:
app: runners-test
spec:
containers:
- name: runners-test
image: mylocaldockerimage
ports:
- containerPort: 80
C02X67GOKL:terraform$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP > PORT(S) AGE
kubernetes ClusterIP 10.100.0.1 443/TCP 8d
runners-test LoadBalancer 10.100.246.180 af3884a05ad7811e99b0e06a70e73221-192467907.us-west-2.elb.amazonaws.com 80:31038/TCP 43m
It's targeting to port a random port 31038, when i connect to my pod and run ps -ef, i can see that a service is running on port 80.
As mentioned in the Kubernetes Service documentation , setting this type will enforce the underlying cloud provider to assign a public IP address to your service and route the traffic on your exposed port ( which is 80 in your case ) to Node Port ( 31038 ) on the kubernetes cluster level.
On cloud providers which support external load balancers, setting the type field to LoadBalancer provisions a load balancer for your Service.
I am trying to learn how to use Kibernetes with Minikube and have the following deployment and service:
---
kind: Service
apiVersion: v1
metadata:
name: exampleservice
spec:
selector:
app: myapp
ports:
- protocol: "TCP"
# Port accessible inside cluster
port: 8081
# Port to forward to inside the pod
targetPort: 8080
# Port accessible outside cluster
nodePort: 30002
type: LoadBalancer
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: myappdeployment
spec:
replicas: 5
template:
metadata:
labels:
app: myapp
spec:
containers:
- name: myapp
image: tutum/hello-world
ports:
- containerPort: 8080
I expect to be able to hit this service from my local machine at
http://192.168.64.2:30002
As per the command: minikube service exampleservice --url but when I try to access this from the browser I get a site cannot be reached error.
Some information that may help debugging:
kubectl get services --all-namespaces:
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default exampleservice LoadBalancer 10.104.248.158 <pending> 8081:30002/TCP 26m
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2h
default user-service-service LoadBalancer 10.110.181.202 <pending> 8080:30001/TCP 42m
kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 2h
kube-system kubernetes-dashboard ClusterIP 10.110.65.24 <none> 80/TCP 2h
I am running minikube on OSX.
This is expected.
Do note that LoadBalancer is for cloud to create external load balancer like ALP/NLP in AWS and something similar in GCP/Azure etc.
Update the service as shown here. here i assume 192.168.64.2 is your minikube ip. if not, update it with minikube ip to make it work.
kind: Service
apiVersion: v1
metadata:
name: exampleservice
spec:
selector:
app: myapp
ports:
- protocol: "TCP"
# Port accessible inside cluster
port: 8081
# Port to forward to inside the pod
targetPort: 80
# Port accessible outside cluster
nodePort: 30002
type: LoadBalancer
externalIPs:
- 192.168.64.2
Now you can access your application at http://192.168.64.2:8081/
If you need to access the application at 30002, you can use it like this
kind: Service
apiVersion: v1
metadata:
name: exampleservice
spec:
selector:
app: myapp
ports:
- protocol: "TCP"
# Port accessible inside cluster
port: 8081
# Port to forward to inside the pod
targetPort: 80
# Port accessible outside cluster
nodePort: 30002
type: NodePort
Your deployment file does not look correct to me.
delete it
kubectl delete deploy/myappdeployment
use this to create again.
apiVersion: apps/v1beta1
kind: Deployment
metadata:
labels:
app: myapp
name: myappdeployment
spec:
replicas: 5
selector:
matchLabels:
app: myapp
strategy: {}
template:
metadata:
labels:
app: myapp
spec:
containers:
- image: tutum/hello-world
name: myapp
ports:
- containerPort: 80
NOTE: Minikube support LoadBalancer services (via minikube tunnel)
you can get the IP and port through which you
can access the service by running
minikube service kubia-http #=> To open a browser with an IP and port
OR
minikube service kubia --url #=> To get the IP and port in the terminal
I have a manifest as the following
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-redis
spec:
selector:
matchLabels:
app: my-redis
replicas: 1
template:
metadata:
labels:
app: my-redis
spec:
containers:
- name: my-redis
image: redis
ports:
- name: redisport1
containerPort: 6379
hostPort: 6379
---
apiVersion: v1
kind: Service
metadata:
name: redis-service
labels:
app: my-redis
spec:
type: NodePort
selector:
name: my-redis
ports:
- name: redisport1
port: 6379
targetPort: 6379
nodePort: 30036
protocol: TCP
This is a sample that reproduces my problem. My intention here is to create a simple cluster that has a pod with a redis container in it, and it should be exposed to my localhost. Still, get services gives me the following output:
redis-service NodePort 10.107.233.66 <none> 6379:30036/TCP 10s
If I swap NodePort with LoadBalancer, I get an external-ip but still port doesn't work.
Can you help me identify why I'm failing to map the 6379 port to my localhost, please?
Thanks,
In order to access your app through node port, you have to use this url
http://{node ip}:{node port}.
If you are using minikube, your minikube ip is the node ip. You can retrieve it using minikube ip command.
You can also use minikube service redis-service --url command to get the url to access your application through node port.
For anybody who's interested in the question, I found the problem. After Ijaz's fix, I also needed to change the selector to match the label in the pod, it was a typo on my end!
pod has "app=my-redis" tag, but Service selector had "name=my-redis". Matching them fixed the access problem.
Dont need the hostPort:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-redis
spec:
selector:
matchLabels:
app: my-redis
replicas: 1
template:
metadata:
labels:
app: my-redis
spec:
containers:
- name: my-redis
image: redis
ports:
- name: redisport1
containerPort: 6379
---
apiVersion: v1
kind: Service
metadata:
name: redis-service
labels:
app: my-redis
spec:
type: NodePort
selector:
name: my-redis
ports:
- name: redisport1
port: 6379
targetPort: 6379
nodePort: 30036
protocol: TCP
now the nodePort 30036 can be used to access the service on any worker node.
If the cluster node is somewhere else and you want to make the port available on you local client , then just do kubectl port forward
kubectl port-forward svc/redis-service 6379:6379
https://kubernetes.io/docs/tasks/access-application-cluster/port-forward-access-application-cluster/
Notes:
On-prem installs of k8s dont support service type of load balancer
ClusterIP is the IP on the pod network
Node IP is the IP of some machine that is running the k8s cluster