Issue with rancher opening external port
Installed rancher 2.6 ,
deployed a springboot app with 8080 port open docker image
Set internal port as 8080, external(nodeport) as 31000 and port on image container as 8080
Trying to access :31000 , getting 404 please help
i'm stuck here!!! Need help
I tried changing the node port, disabling the firewall and restarting machine
The Fact you are getting a 404 is that something is answering your request.
I would do the following to try to troubleshoot.
Use port-forward to check your app is running on the cluster fine:
kubectl port-forward svc/movies-db-np 8080
Check it on http://localhost:8080
Verify the service has the correct selector for your pod/deployment e.g:
apiVersion: v1
kind: Service
metadata:
name: myapp
spec:
type: NodePort
ports:
- name: http
port: 8080
protocol: TCP
targetPort: 8080
nodePort: 31000
selector:
app: myapp
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: myapp
name: myapp
spec:
replicas: 1
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
spec:
containers:
- image: my.docker/myapp:1.0.0
name: myapp
ports:
- containerPort: 8080
name: http
protocol: TCP
...
Note here, the service will match pods with label app=myapp.
Related
I can't for the life of me get this to connect.
It is a golang application using Kubernetes.
The docker file runs just fine, the pod launches but the connection times out.
apiVersion: v1
kind: Service
metadata:
name: ark-service
namespace: ark
spec:
type: NodePort
ports:
- port: 80
targetPort: 8080
nodePort: 30008
selector:
app: ark-api
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: ark-backend
namespace: ark
spec:
replicas: 1
selector:
matchLabels:
app: ark-api
template:
metadata:
labels:
app: ark-api
spec:
imagePullSecrets:
- name: regcred
containers:
- name: ark-api-container
image: xxx
imagePullPolicy: Always
resources:
limits:
memory: "128Mi"
cpu: "500m"
ports:
- name: web
containerPort: 8080
I am able to boot the docker container just fine and it runs.
Turns out the container gets terminated and I have no idea why.
You could check wheather the port 8080 is listening inside the container
kubectl exec -it <pod_namen> -n <namespace> -- netstat -ntpl
if there is no netstat command in the container, you could try to build a base image with it.
Check whether the port 30080 is listening on the node. Run the following command on the node
netstat -ntpl | grep 30080
Also you could try not to specify the node port in the service yaml, let the kubernetes to choose the nodeport for you. That could avoid to specify the port which is already using in your node.
apiVersion: v1
kind: Service
metadata:
name: ark-service
namespace: ark
spec:
type: ClusterIP
selector:
component: ark-api
ports:
- port: 80
targetPort: 8080
Try using clusterIP instead of nodeport, if you are using any kind of Ingress then you have to create rules in your ingress config so It can expose your service to the outside web via your load balancer.
I deleted the service and used port forwarding and was able to boot everything. I'll have to circle back to the service to try and figure it out.
Background
I am using Docker for Windows v20.10.6 (with Kubernetes enabled).
I have created two simple, out-of-the-box .NET 5.0 applications:
1. Web API (reaching through HTTP, listening on port 7070)
2. Web App (MVC) that shows a parsed table from the Web API (listening on port 80)
A. ✔️ Created a connection between the applications using Docker Swarm Mode
Created a swarm using docker swarm init
Created an 'overlay' driver network named personal-overlay.
Created the Web API service using docker service create –-network personal-overlay --name api webapi
Created the Web App service using docker service create --name web –-network personal-overlay -p 30080:80 webapp
B. ✔️ Created a generic NGINX deployment and service
deployment:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
tier: frontend
spec:
selector:
matchLabels:
app: myapp
replicas: 1
template:
metadata:
name: nginx
labels:
app: myapp
spec:
containers:
- name: nginx
image: nginx
service:
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
type: NodePort
ports:
- targetPort: 80
port: 80
nodePort: 30080
selector:
app: myapp
I could access the NGINX through http://localhost:30080 without an issue (using the web browser).
❌ The issue I'm currently facing
Tagged the images test/api and test/web
Created the same files using those Visual Studio images:
deployment:
apiVersion: apps/v1
kind: Deployment
metadata:
name: test-deployment
labels:
tier: frontend
spec:
selector:
matchLabels:
app: myapp
replicas: 1
template:
metadata:
name: test-pod
labels:
app: myapp
spec:
containers:
- name: api
image: test/api
imagePullPolicy: Never
- name: web
image: test/web
imagePullPolicy: Never
service:
apiVersion: v1
kind: Service
metadata:
name: test-service
spec:
type: NodePort
ports:
- targetPort: 80
port: 80
nodePort: 30080
selector:
app: myapp
Yet, I can not access http://localhost:30080.
EDIT [1]:
I am trying to access it through the web browser, and I get an HTTP ERROR 500: "Failed to load resource: the server responded with a status of 500 (Internal Server Error)."
Whenever I am using curl -I http://localhost:30080 I get the following response:
HTTP/1.1 500 Internal Server Error
Date: Thu, 13 May 2021 08:20:25 GMT
Server: Kestrel
Content-Length: 0
EDIT [2]:
I even tried to scale it down into just this one pod (the web application).
pod:
apiVersion: v1
kind: Pod
metadata:
name: consumer-pod
labels:
name: consumer-pod
app: api-and-consumer
spec:
containers:
- name: consumer
image: test/web
imagePullPolicy: Never
ports:
- containerPort: 80
service:
apiVersion: v1
kind: Service
metadata:
name: consumer-external-svc
labels:
name: consumer-external-svc
app: api-and-consumer
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
nodePort: 30080
selector:
name: consumer-pod
app: api-and-consumer
Yet it does not work (with nor without the ports section at the pod YAML file).
These are the logs I get using the kubectl logs web-pod-<fullname> command (which says it is actually listening on port 80):
←[40m←[1m←[33mwarn←[39m←[22m←[49m: Microsoft.AspNetCore.DataProtection.Repositories.FileSystemXmlRepository[60]
Storing keys in a directory '/root/.aspnet/DataProtection-Keys' that may not be persisted outside of the container. Protected data will be unavailable when container is destroyed.
←[40m←[1m←[33mwarn←[39m←[22m←[49m: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[35]
No XML encryptor configured. Key {70ddc140-9846-4052-b869-8bcc5250d39e} may be persisted to storage in unencrypted form.
←[40m←[32minfo←[39m←[22m←[49m: Microsoft.Hosting.Lifetime[0]
Now listening on: http://[::]:80
←[40m←[32minfo←[39m←[22m←[49m: Microsoft.Hosting.Lifetime[0]
Application started. Press Ctrl+C to shut down.
←[40m←[32minfo←[39m←[22m←[49m: Microsoft.Hosting.Lifetime[0]
Hosting environment: Production
←[40m←[32minfo←[39m←[22m←[49m: Microsoft.Hosting.Lifetime[0]
Content root path: /app
I should also mention that using kubectl cluster-info dump I get the following line (for the service though, not the pod itself):
time="2021-05-13T10:56:35Z" level=error msg="Port 30080 for service web-external-svc is already opened by another service"
I am trying to deploy simple spring boot REST service on minikube (Windows-10). Below are my configuration
Docker file
FROM openjdk:8-jdk-alpine
ENTRYPOINT ["/usr/bin/java", "-jar", "/usr/share/myservice/minikube-spring-boot-demo-0.0.1-SNAPSHOT.jar"]
ADD target/minikube-spring-boot-demo-0.0.1-SNAPSHOT.jar /usr/share/myservice/lib
ARG JAR_FILE
ADD target/${JAR_FILE} /usr/share/myservice/minikube-spring-boot-demo-0.0.1-SNAPSHOT.jar
EXPOSE 8080
docker image is running fine and i am able to run the app.
docker run -p 8080:8080 minikube-spring-boot-demo:0.0.1-SNAPSHO
Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: minikube-spring-boot-demo
spec:
selector:
matchLabels:
app: minikube-spring-boot-demo
tier: backend
replicas: 3
template:
metadata:
labels:
app: minikube-spring-boot-demo
tier: backend
spec:
containers:
- name: demo-backend
image: nirajsonawane/minikube-spring-boot-demo:0.0.1-SNAPSHOT
imagePullPolicy: Always
ports:
- containerPort: 8080
Service
apiVersion: v1
kind: Service
metadata:
name: minikube-spring-boot-demo-service
spec:
selector:
app: minikube-spring-boot-demo
tier: backend
ports:
- port: 8080
targetPort: 8080
nodePort: 30008
type: NodePort
kubectl get all status
kubectl cluster-info
minikube logs
Service Details
i am not able to access the rest endpoint using service-ip:Nodeport/Uri
http://127.0.0.1:30008/hello
http://172.17.0.2:30008/hello
Anything i am missing here? any inputs will be useful.
output of netstat -a
minikube is running in a virtual machine. Services can't be accessed through either localhost or 127.0.0.1 out of the machine.
Try to run minikube service minikube-spring-boot-demo-service. It will show service details and open the service in the browser.
You can get you cluster ip using below command
kubectl get nodes -o wide
then run below to get nodeport
kubectl get svc -o wide -n <namespace>
get the port of your NodePort Svc
then your application will be running on http://:port(svc Nodeport )
In your case it might be running on
http://127.0.0.1:30008/hello
I'm following the spring and kubernetes integration tutorial:
https://spring.io/guides/gs/spring-boot-kubernetes/
In my current scenario, I have 1 master and 2 workers servers.
When I deploy the file below using the command kubectl apply -f deployment.yaml, I can make a request from within the master server using kubectl port-forward svc/demo 8080:8080 and curl localhost:8080/actuator/health.
What I want to do is an external request (a public computer - my computer) to access the service that I created (kubernetes_master_ip:8080/actuator), but when I try this, I get "connection refused".
What is missing?
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: demo
name: demo
spec:
replicas: 1
selector:
matchLabels:
app: demo
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: demo
spec:
containers:
- image: springguides/demo
name: demo
resources: {}
status: {}
---
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: demo
name: demo
spec:
ports:
- name: 8080-8080
port: 8080
protocol: TCP
targetPort: 8080
selector:
app: demo
type: ClusterIP
status:
loadBalancer: {}
You need to change the type of service to expose the application. There are two ways:
- LoadBalancer type: (Only on cloud providers)
- NodePort type: Can be done on-premise or minikube.
Change your service yaml to below:
apiVersion: v1
kind: Service
metadata:
labels:
app: demo
name: demo
spec:
ports:
- name: 8080-8080
port: 8080
nodePort: 31234
protocol: TCP
targetPort: 8080
selector:
app: demo
type: NodePort
Once the service is executed. check the application Node IP on which container is created.
kubectl get pods -o wide
then try to access the application at:
http://node_ip:31234/actuator
you can change your service type to load balancer. Which will expose your service via IP address to the external internet. Service type load balancer will only work with Cloud providers.
For more details you can visit : https://kubernetes.io/docs/concepts/services-networking/
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: demo
name: demo
spec:
ports:
- name: 8080-8080
port: 8080
protocol: TCP
targetPort: 8080
selector:
app: demo
type: LoadBalancer
save as yaml and execute it. it will provide the IP address.
You can access service via IP
Kubectl get svc
After deploying a golang server container and gke load balancer I can successfully connect to the external ip of the load balancer, but no data reaches the server container.
It works as expected when I run the server container locally and point the client at localhost. I changed it to serve http requests and it worked fine with the same kubernetes manifests. However, if I try to serve both tcp and http (on different ports) then neither work on gke but again works fine locally. So I suspect it probably has something to do with either how I configured the load balancer or how I'm listening for tcp connections in the server breaks something when running on gke but not locally.
K8s Service Manifest
apiVersion: v1
kind: Service
metadata:
name: steel-server-service
spec:
type: LoadBalancer
selector:
app: steel-server
ports:
- protocol: TCP
name: tcp
port: 12345
targetPort: 12345
K8s Deployment Manifest
apiVersion: apps/v1
kind: Deployment
metadata:
name: steel-server-deployment
labels:
app: steel-server
spec:
replicas: 1
selector:
matchLabels:
app: steel-server
template:
metadata:
labels:
app: steel-server
spec:
containers:
- name: steel-server
image: gcr.io/<my-project-id>/steel-server:latest
ports:
- containerPort: 12345
name: tcp
Relevent Go TCP Server Code
server, err := net.Listen("tcp", ":12345")
if err != nil {
log.Fatalln("Couldn't start up tcp server: ", err)
}
Can you try first with kubectl get svc so you get to know which ports are open with load balancer as you got external ip from GCP as type:loadbalancer.
apiVersion: v1
kind: Service
metadata:
name: steel-server-service
spec:
type: LoadBalancer
selector:
app: steel-server
ports:
- protocol: TCP
name: tcp
port: 80
targetPort: 12345
Try with this service config i change port to 80 while target port of same as container port.