CODEWITHSUNDEEP
kubernetesyamlkubernetes-helm
Arkon
Arkon

Reputation: 2954

Helm chart restart pods when configmap changes

I am trying to restart the pods when there is a confimap or secret change. I have tried the same piece of code as described in: https://github.com/helm/helm/blob/master/docs/charts_tips_and_tricks.md#automatically-roll-deployments-when-configmaps-or-secrets-change However, after updating the configmap, my pod does not get restarted. Would you have any idea what could has been done wrong here?

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: {{ template "app.fullname" . }}
  labels:
    app: {{ template "app.name" . }}
    {{- include "global_labels" . | indent 4 }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ template "app.name" . }}
      release: {{ .Release.Name }}
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yml") . | sha256sum }}
        checksum/secret: {{ include (print $.Template.BasePath "/secret.yml") . | sha256sum }}

Upvotes: 20

Views: 46317

Answers (4)

armourbear
armourbear

Reputation: 616

https://helm.sh/docs/howto/charts_tips_and_tricks/#automatically-roll-deployments Helm3 has this feature now. deployments are rolled out when there is change in configmap template file.

Often times ConfigMaps or Secrets are injected as configuration files in containers or there are other external dependency changes that require rolling pods. Depending on the application a restart may be required should those be updated with a subsequent helm upgrade, but if the deployment spec itself didn't change the application keeps running with the old configuration resulting in an inconsistent deployment.

The sha256sum function can be used to ensure a deployment's annotation section is updated if another file changes:

kind: Deployment
spec:
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
[...]

Upvotes: 21

nitin vij
nitin vij

Reputation: 121

it worked for me, below is the code snippet from my deployment.yaml file, make sure your configmap and secret yaml file are same as what referred in the annotations:

spec:
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/my-configmap.yaml") . | sha256sum }}
        checksum/secret: {{ include (print $.Template.BasePath "/my-secret.yaml") . | sha256sum }}

Upvotes: 12

cpani
cpani

Reputation: 41

I deployed pod with configmap with this feature https://helm.sh/docs/howto/charts_tips_and_tricks/#automatically-roll-deployments. When I edited the configmap at runtime , it didn't trigger the roll-deployment.

Upvotes: 0

Rico
Rico

Reputation: 61521

Neither Helm nor Kubernetes provide a specific rolling update for a ConfigMap change. The workaround has been for a while is to just patch the deployment which triggers the rolling update:

kubectl patch deployment your-deployment -n your-namespace -p '{"spec":{"template":{"metadata":{"annotations":{"date":"$(date)"}}}}}'

And you can see the status:

kubectl rollout status deployment your-deployment

Note this works on a nix machine. This is until this feature is added.

Update 05/05/2021

Helm and kubectl provide this now:

Helm: https://helm.sh/docs/howto/charts_tips_and_tricks/#automatically-roll-deployments

kubectl: kubectl rollout restart deploy WORKLOAD_NAME

Upvotes: 15

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