I'm trying to override dnsconfig (searchdomain particularly) of my alpine based pod.
But it seems dnsconfig is available in pod object.
Is there anyway to provide dnsconfig in deployment object or any other workaround to override searchdomain of that particular pod.
You can specify the dnsConfig inside spec.template object.
This is basically a template for your Deployment which will be used to create pods.
Deployment might look like the following:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.17
ports:
- containerPort: 80
dnsPolicy: "None"
dnsConfig:
nameservers:
- 1.2.3.4
searches:
- test.test.com
- test.test.org
Related
So I followed this tutorial that explains how to building containerized microservices in Golang, Dockerize and Deploy to Kubernetes.
https://www.youtube.com/watch?v=H6pF2Swqrko
I got to the point that I can access my app via the minikube ip (mine is 192.168.59.100).
I set up kubernetes, I currently have 3 working pods but I can not open my golang app through kubernetes with the url that the kubectl shows me: "192.168.59.100:31705..."
^
|
here
I have a lead...
when i search "https://192.168.59.100:8443/" error 403 comes up:
Here is my deployment.yml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: web-deployment
labels:
app: web
spec:
replicas: 3
selector:
matchLabels:
app: web
template:
metadata:
labels:
app: web
spec:
containers:
- name: go-web-app
image: go-app-ms:latest
imagePullPolicy: IfNotPresent
ports:
- containerPort: 80
Here is my service.yml:
apiVersion: v1
kind: Service
metadata:
name: web-service
spec:
type: NodePort
selector:
app.kubernetes.io/name: web
ports:
- port: 80
targetPort: 80
Your service's selector tries to match pods with label: app.kubernetes.io/name: web, but pods have app: web label. They do not match. The selector on service must match labels on pods. As you use deployment object, this means the same labels as in spec.template.metadata.labels.
#Szczad has correctly described the problem. I wanted to suggest a way of avoiding that problem in the future. Kustomize is a tool for building Kubernetes manifests. It is built into the kubectl command. One of its features is the ability to apply a set of common labels to your resources, including correctly filling in selectors in services and deployments.
If we simplify your Deployment to this (in deployment.yaml):
apiVersion: apps/v1
kind: Deployment
metadata:
name: web-deployment
spec:
replicas: 3
template:
spec:
containers:
- name: go-web-app
image: go-app-ms:latest
imagePullPolicy: IfNotPresent
ports:
- containerPort: 80
And your Service to this (in service.yaml):
apiVersion: v1
kind: Service
metadata:
name: web-service
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
And we place the following kustomization.yaml in the same directory:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
commonLabels:
app: web
resources:
- deployment.yaml
- service.yaml
Then we can deploy this application by running:
kubectl apply -k .
And this will result in the following manifests:
apiVersion: v1
kind: Service
metadata:
labels:
app: web
name: web-service
spec:
ports:
- port: 80
targetPort: 80
selector:
app: web
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: web
name: web-deployment
spec:
replicas: 3
selector:
matchLabels:
app: web
template:
metadata:
labels:
app: web
spec:
containers:
- image: go-app-ms:latest
imagePullPolicy: IfNotPresent
name: go-web-app
ports:
- containerPort: 80
As you can see here, the app: web label has been applied to the deployment, to the deployment selector, to the pod template, and to the service selector.
Applying the labels through Kustomize like this means that you only need to change the label in one place. It makes it easier to avoid problems caused by label mismatches.
Need some basic help with EKS. Not sure what I am doing wrong.
I have a java springboot application as a docker container in ECR.
I created a simple deployment script
deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: microservice-deployment
labels:
app: java-microservice
spec:
replicas: 2
selector:
matchLabels:
app: java-microservice
template:
metadata:
labels:
app: java-microservice
spec:
containers:
- name: java-microservice-container
image: xxxxxxxxx.dkr.ecr.us-west-2.amazonaws.com/yyyyyyy
ports:
- containerPort: 80
I created a loadbalancer to expose this outside
loadbalancer.yaml
apiVersion: v1
kind: Service
metadata:
name: java-microservice-service
spec:
type: LoadBalancer
selector:
app: java-microservice
ports:
- protocol: TCP
port: 80
targetPort: 80
The pods got created. I see they are running
When I do kubectl get service java-microservice-service, I do see the loadbalancer is running
When I go to browser and try to access the application via http://loadbalancer-address, I cannot reach it.
What am I missing? How do I go about debugging this?
thanks in advance
ok. so i changed the port in my yaml files to 8080 and it seems to be working fine.
I'm running a simple spring microservice project with Minikube. I have two projects: lucky-word-client (on port 8080) and lucky-word-server (on port 8888). lucky-word-client has to communicate with lucky-word-server. I want to inject the static Nodeport of lucky-word-server (http://192.*..100:32002) as an environment variable in my Kuberenetes deployment script of lucky-word-client. How I could do?
This is deployment of lucky-word-server:
apiVersion: apps/v1
kind: Deployment
metadata:
name: lucky-server
spec:
selector:
matchLabels:
app: lucky-server
replicas: 1
template:
metadata:
labels:
app: lucky-server
spec:
containers:
- name: lucky-server
image: lucky-server-img
imagePullPolicy: Never
ports:
- containerPort: 8888
This is the service of lucky-word-server:
kind: Service
apiVersion: v1
metadata:
name: lucky-server
spec:
selector:
app: lucky-server
ports:
- protocol: TCP
targetPort: 8888
port: 80
nodePort: 32002
type: NodePort
This is the deployment of lucky-word-client:
apiVersion: apps/v1
kind: Deployment
metadata:
name: lucky-client
spec:
selector:
matchLabels:
app: lucky-client
replicas: 1
template:
metadata:
labels:
app: lucky-client
spec:
containers:
- name: lucky-client
image: lucky-client-img
imagePullPolicy: Never
ports:
- containerPort: 8080
This is the service of lucky-word-client:
kind: Service
apiVersion: v1
metadata:
name: lucky-client
spec:
selector:
app: lucky-client
ports:
- protocol: TCP
targetPort: 8080
port: 80
type: NodePort
Kubernetes automatically injects services as environment variables. https://kubernetes.io/docs/concepts/services-networking/service/#environment-variables
But you should not use this. This won't work unless all the services are in place when you create the pod. It is inspired by "docker" which also moved on to DNS based service discovery now. So "environment based service discovery" is a thing of the past.
Please rely on DNS service discovery. Minikube ships with kube-dns so you can just use the lucky-server hostname (or one of lucky-server[.default[.svc[.cluster[.local]]]] names). Read the documentation: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/
I'm quite new to kubernetes, and I'm trying to deploy a docker container to kubernetes. I already have a docker container running on AWS. I am trying to deploy the yml file through the following command:
kops create -f deployment.yml --state=s3://mybucket
However whenever I try to deploy my yml file, I get a message saying:
error parsing file "deployment.yml": no kind "Cluster" is registered for version "v1"
My yml file looks like this:
apiVersion: v1
kind: Cluster
metadata:
name: containers
spec:
containers:
- name: container
image: [idnumber].dkr.ecr.eu-west-2.amazonaws.com/myfirstcontainer
ports:
- containerPort: 3000
Grateful for any help!
Thanks
There is no kind: Cluster in kubernetes API v1.
You should use kind: Pod if you want to run only one pod or use deployment, if you want to create controller which manages your pod:
apiVersion: apps/v1beta2 # for versions before 1.8.0 use apps/v1beta1
kind: Deployment
Also, you have some issues with formatting in your deployment.yml file.
The final deployment.yml should be for pod:
apiVersion: v1
kind: Pod
metadata:
name: containers
spec:
containers:
- name: container
image: [idnumber].dkr.ecr.eu-west-2.amazonaws.com/myfirstcontainer
ports:
- containerPort: 3000
or for deployment:
apiVersion: apps/v1beta1 # for versions starting from 1.8.0 use apps/v1beta2
kind: Deployment
metadata:
name: containers
spec:
replicas: 1
selector:
matchLabels:
app: some_app
template:
metadata:
labels:
app: some_app
spec:
containers:
- name: container
image: [idnumber].dkr.ecr.eu-west-2.amazonaws.com/myfirstcontainer
ports:
- containerPort: 3000
I am using Kubernetes to run a Docker service. This is a defective service that requires a restart everyday. For multiple reasons we can't programmatically solve the problem and just restarting the docker everyday will do.
When I migrated to Kubernetes I noticed I can't do "docker restart [mydocker]" but as the docker is a deployment with reCreate strategy I just need to delete the pod to have Kubernetes create a new one.
Can I automate this task of deleting the Pod, or an alternative one to restart it, using a CronTask in Kubernetes?
Thanks for any directions/examples.
Edit: My current deployment yml:
apiVersion: v1
kind: Service
metadata:
name: et-rest
labels:
app: et-rest
spec:
ports:
- port: 9080
targetPort: 9080
nodePort: 30181
selector:
app: et-rest
tier: frontend
type: NodePort
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: et-rest
labels:
app: et-rest
spec:
strategy:
type: Recreate
template:
metadata:
labels:
app: et-rest
tier: frontend
spec:
containers:
- image: et-rest-image:1.0.21
name: et-rest
ports:
- containerPort: 9080
name: et-rest
volumeMounts:
- name: tz-config
mountPath: /etc/localtime
volumes:
- name: tz-config
hostPath:
path: /usr/share/zoneinfo/Europe/Madrid
You can use a scheduled job pod:
A scheduled job pod has build in cron behavior making it possible to restart jobs, combined with the time-out behavior, it leads to your required behavior or restarting your app every X hours.
apiVersion: batch/v2alpha1
kind: ScheduledJob
metadata:
name: app-with-timeout
spec:
schedule: 0 * * * ?
jobTemplate:
spec:
activeDeadlineSeconds: 3600*24
template:
spec:
containers:
- name: yourapp
image: yourimage