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Kubernetes: Difference between revisions
→Services
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kubectl run busybox-shell --rm -i --tty --image odise/busybox-curl -- sh | kubectl run busybox-shell --rm -i --tty --image odise/busybox-curl -- sh | ||
</syntaxhighlight> | </syntaxhighlight> | ||
==Deployments== | |||
In most cases, you will use deployments to provision pods.<br> | |||
Deployments internally use replicasets to create multiple identical pods.<br> | |||
This is great for things such as webservers or standalone services which are not stateful. | |||
In most cases, you can stick a service in front which will round-robin requests to different pods in your deployment. | |||
{{hidden | Example Deployment | | |||
<syntaxhighlight lang="yaml"> | |||
apiVersion: apps/v1 | |||
kind: Deployment | |||
metadata: | |||
name: nextcloud-app | |||
labels: | |||
app: nextcloud | |||
spec: | |||
replicas: 1 | |||
selector: | |||
matchLabels: | |||
pod-label: nextcloud-app-pod | |||
template: | |||
metadata: | |||
labels: | |||
pod-label: nextcloud-app-pod | |||
spec: | |||
containers: | |||
- name: nextcloud | |||
image: public.ecr.aws/docker/library/nextcloud:stable | |||
ports: | |||
- containerPort: 80 | |||
env: | |||
- name: MYSQL_HOST | |||
value: nextcloud-db-service | |||
- name: MYSQL_DATABASE | |||
value: nextcloud | |||
- name: MYSQL_USER | |||
valueFrom: | |||
secretKeyRef: | |||
name: nextcloud-db-credentials | |||
key: username | |||
- name: MYSQL_PASSWORD | |||
valueFrom: | |||
secretKeyRef: | |||
name: nextcloud-db-credentials | |||
key: password | |||
volumeMounts: | |||
- name: nextcloud-app-storage | |||
mountPath: /var/www/html | |||
volumes: | |||
- name: nextcloud-app-storage | |||
persistentVolumeClaim: | |||
claimName: nextcloud-app-pvc | |||
</syntaxhighlight> | |||
}} | |||
==StatefulSets== | |||
[https://kubernetes.io/docs/tutorials/stateful-application/basic-stateful-set/ StatefulSets basics] | |||
Stateful sets are useful when you need a fixed number of pods with stable identities.<br> | |||
Pods created by stateful sets have a unique number suffix which allows you to query a specific pod.<br> | |||
Typically, you will want to use a headless service (i.e. without ClusterIP) to give local dns records to each service. | |||
In most cases, you will want to look for a helm chart instead of creating your own stateful sets. | |||
==Services== | ==Services== | ||