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"
Related
We have lunched .Net microservice on container and published it on EKS Cluster.
It's working fine on http.
We follow the link to deploy .Net microservice as deploy as a container.
https://dotnet.microsoft.com/en-us/learn/aspnet/microservice-tutorial/docker-file
We used below deploy.yaml
**---
apiVersion: apps/v1
kind: Deployment
metadata:
name: mymicroservice
spec:
replicas: 1
template:
metadata:
labels:
app: mymicroservice
spec:
containers:
- name: mymicroservice
image: [YOUR DOCKER ID]/mymicroservice:latest
ports:
- containerPort: 80
env:
- name: ASPNETCORE_URLS
value: http://*:80
selector:
matchLabels:
app: mymicroservice
apiVersion: v1
kind: Service
metadata:
name: mymicroservice
spec:
type: LoadBalancer
ports:
port: 80
selector:
app: mymicroservice**
This exposed our microservices behind classic load balancer. It's working fine on Http.
but we facing challenges on HTTPS. How can this be achieved? If we need to use Nginx Ingress Controller how that yaml we can tune according to our deployment.yaml
I'm learning Kubernetes and i developed a simple spring-boot project that expose a simple API /getHomeSpace. When invoked, this API making a request to an external API that is the following: https://api.nasa.gov/planetary/apod. When i start-up my app with docker-compose it works perfectly. But when i set up kubernetes pod and service i receive the following error:
Error during callApod: I/O error on GET request for "https://api.nasa.gov/planetary/apod": No subject alternative DNS name matching api.nasa.gov found.; nested exception is javax.net.ssl.SSLHandshakeException: No subject alternative DNS name matching api.nasa.gov found.
My kubernetes config files:
apiVersion: apps/v1
kind: Deployment
metadata:
name: api-deployment
spec:
replicas: 1
selector:
matchLabels:
component: server
template:
metadata:
labels:
component: server
spec:
containers:
- name: server
image: antonio94c/view_api:11
ports:
- containerPort: 8080
apiVersion: v1
kind: Service
metadata:
name: api-service
spec:
type: ClusterIP
ports:
- port: 8080
targetPort: 8080
#nodePort: 30000
selector:
component: server
What i'm missing??
I tried to read Kubernetes doc and stackoverflow related topics, but i didn't found a solution.
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.
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
I created a service and use nodeport etc but couldn't access the service.
I created a web-service.yaml file with the following content and used kubectl to create the Service:
apiVersion: v1
kind: Service
metadata:
name: web-service
labels:
app: web-service
spec:
type: NodePort
ports:
- port: 80
protocol: TCP
selector:
app: webserver
and the webserver.yaml file with the following Deployment details
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: webserver
spec:
replicas: 3
template:
metadata:
labels:
run: webserver
spec:
containers:
- name: webserver
image: nginx:alpine
ports:
- containerPort: 80
In your deployment, label is run=webserver, but in your service, label is app=webserver. The service uses app=webserver as a Selector, through which it selects three pods that have the label "app" set to "webserver". In this case none of the pods has the label "app" so the deployment is not successfully exposed as a service. The label names and values in the deployment and service should match.