How to do controlled rollout using Kubernetes deployment - kubernetes

Question

We have 1000 store nodes and need to deploy an application image on every kubernetes node by rolling out in the below order and would like to specify the deployment node details during the deployment. Is there a way to specify node details in the command line when we execute kubectl create or apply deployment commands?
This application image would be configured to store/node specific details during container/POD creation.
1 node on day 1,
10 node on day 2,
100 node on day 3 etc.

Answer 1

Answering on the question from the title:
How to do controlled rollout using Kubernetes deployment
You can create a Deployment that will have specific fields in its manifest that will configure the way Kubernetes handles it.
With the fields like: podAntiAffinity, requiredDuringSchedulingIgnoredDuringExecution you can ensure that Kubernetes will distribute the Pods equally across the cluster Nodes. You can read more about it by following below documentation:
Kubernetes.io: Docs: Concepts: Scheduling eviction: Assign Pod to Node
Having in mind following rollout schedule:
DAY
REPLICAS_COUNT
1
1
2
10
3
100
4
1000
You could use CI/CD tools (like for example Jenkins) to rollout (change) the amount of replicas of your Deployment across a specific schedule.
You could create a Jenkins pipeline with a deploy stage where you could put your own command with it's scheduler (or delay).
The example of such Deployment that could be used with Jenkins is following:
cat << EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
selector:
matchLabels:
app: nginx
replicas: ${REPLICAS_COUNT}
template:
metadata:
labels:
app: nginx
spec:
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values:
- nginx
topologyKey: "kubernetes.io/hostname"
containers:
- name: nginx
image: nginx
EOF
This Deployment will assign Pods to the Nodes that aren't already having an already running replica of this Deployment (i.e. 1 Pod = 1 Node). If the amount of Pods exceeds the amount of Nodes they will remain in Pending state.
Additional resources:
Jenkins.io: Doc: Pipeline: Tour: Environment
Kubernetes.io: Docs: Concepts: Workloads: Controllers: Deployment