Table of Contents |
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Converting from Docker-Compose
The first step will be to install kompose and convert our docker-compose.yml to kubernetes yaml files.
Install kompose
> brew install kompose
Startup without Converting
For simple docker-compose files, we can skip the steps pf converting and start up directly using kompose up.Start up directly
> kompose up
Exporting
For more complicated docker-compose files, we will need to export and then modify the converted files.Export docker-compose
> kompose convert
Code Block |
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$ kompose convert WARN Volume mount on the host "/Users/john.mehan/projects/cloud/deployment/is-config/IND" isn't supported - ignoring path on the host INFO Kubernetes file "cloudservice-service.yaml" created INFO Kubernetes file "isservice-service.yaml" created INFO Kubernetes file "postgres-service.yaml" created INFO Kubernetes file "redis-service.yaml" created INFO Kubernetes file "cloudservice-deployment.yaml" created INFO Kubernetes file "isservice-deployment.yaml" created INFO Kubernetes file "isservice-claim0-persistentvolumeclaim.yaml" created INFO Kubernetes file "postgres-deployment.yaml" created INFO Kubernetes file "db-volume-persistentvolumeclaim.yaml" created INFO Kubernetes file "redis-deployment.yaml" created |
Create
...
Kubernetes pods in Cluster
We are using minkube for our cluster. Lets start by making sure it is running:
Might have to have minikube up and running for this to work
> minikube start
Code Block |
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$ minikube start |
Using the yaml files created by kompose export, lets create our pods:
Code Block |
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$ kubectl create -f cloudservice-service.yaml,isservice-service.yaml,postgres-service.yaml,redis-service.yaml,cloudservice-deployment.yaml,isservice-deployment.yaml,isservice-claim0-persistentvolumeclaim.yaml,postgres-deployment.yaml,db-volume-persistentvolumeclaim.yaml,redis-deployment.yaml service/cloudservice created service/isservice created service/postgres created service/redis created deployment.extensions/cloudservice created deployment.extensions/isservice created persistentvolumeclaim/isservice-claim0 created deployment.extensions/postgres created persistentvolumeclaim/db-volume created deployment.extensions/redis created |
Pulling image from Docker Registry
Kubernetes will pull docker images from docker hub by default. For our own custom images, we will pull them from our local docker registry.
For this to work we need to
- create a secret in the cluster that holds our authorization token
- update our deployment yaml files to include this secret
- setup an ssh tunnel between our localhost running docker registry and our cluster (minikube)
Create a Secret in the cluster that holds your authorization token
> kubectl create secret docker-registry regcred --docker-server=<your-registry-server> --docker-username=<your-name> --docker-password=<your-pword> --docker-email=<your-email>
Code Block |
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$ kubectl create secret docker-registry regcred --docker-server=http://localhost:5000/ --docker-username=username --docker-password=password --docker-email=john.mehan@irdeto.com secret/regcred created |
Revise deployment.yaml files
Add imagePullSecrets section to your deployment yaml files:
imagePullSecrets:
- name: regcred
example:
Code Block |
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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
...
spec:
replicas: 1
strategy:
type: Recreate
template:
metadata:
creationTimestamp: null
labels:
io.kompose.service: isservice
spec:
containers:
- image: localhost:5000/safa_is:0.1
name: isservice
ports:
- containerPort: 8080
resources: {}
tty: true
volumeMounts:
- mountPath: /home/irdeto/CONF/ISF/IND
name: is-volume
restartPolicy: Always
volumes:
- name: is-volume
persistentVolumeClaim:
claimName: is-volume
imagePullSecrets:
- name: regcred
status: {} |
Setup SSH Tunnel
We will setup an SSH Tunnel in order to allow kubernetes to pull images from our local docker registry.
Code Block |
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$ ssh -i ~/.minikube/machines/minikube/id_rsa docker@$(minikube ip) -R 5000:localhost:5000 |
References
Reference | URL |
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Translate docker compose to Kubernetes | https://kubernetes.io/docs/tasks/configure-pod-container/translate-compose-kubernetes/ |
Kotacoda Kubernetes Playground | https://www.katacoda.com/courses/kubernetes/playground |
Pull an image from a Private Registry | https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/ |