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Generic helm chart for applications which:

• are stateless
• creates only namespace scoped resources (e.g. it doesn't need CRB - Cluster Role Bindings)
• don't need privileged containers
• don't call the underlying Kubernetes API or use the underlying etcd as a database by defining custom resources
• run either as deployment, job or cronjob

To install the chart with the release namemy-application in namespacetest:

helm repo add stakater https://stakater.github.io/stakater-chartshelm repo updatehelm install my-application stakater/application --namespacetest

To uninstall the chart:

helm delete --namespacetest my-application

Name format of ConfigMap, Secret, SealedSecret and ExternalSecret is{{ template "application.name" $ }}-{{ $nameSuffix }} then:

• {{ template "application.name" }} is a helper function that outputs.Values.applicationName if exist else return chart name as output
• nameSuffix is the each key insecret.files,configMap.files,sealedSecret.files andexternalSecret.files

For example if we have following values file:

applicationName:helloworld# {{ template "application.name" $ }}configMap:files:config:# {{ $nameSuffix }}key:value

then the configmap name will be namedhelloworld-config.

In order to use environment variable in deployment or cronjob, you will have to provide environment variable inkey/value pair inenv value. where key being environment variable key and value varies in different scenarios

• For simple key/value environment variable, just providevalue: <value>

  env:KEY:value:MY_VALUE

• To get environement variable value fromConfigMap

  Suppose we have a configmap created from application chart

  applicationName:my-applicationconfigMap:enabled:truefiles:application-config:LOG:DEBUGVERBOSE:v1

  To get environment variable value from above created configmap, we will need to add following

  env:APP_LOG_LEVEL:valueFrom:configMapKeyRef:name:my-application-application-configkey:LOG

  To get all environment variables key/values fromConfigMap, where configmap key being key of environment variable and value being value

  envFrom:application-config-env:type:configmapnameSuffix:application-config

  You can either providenameSuffix which means name added after prefix<applicationName>- or static name withname of configmap.

  You can specify whether the configmap is mandatory or optional for the pod to start with theoptional: true/false value.

  Note: first key afterenvFrom is just used to uniquely identify different objects inenvFrom block. Make sure to keep it unique and relevant.

• To get environment variable value fromSecret

  Suppose we have secret created from application chart

  applicationName:my-applicationsecret:enabled:truefiles:db-credentials:PASSWORD:skljd#2Qer!!USER:postgres

  To get environment variable value from above created secret, we will need to add following

  env:KEY:valueFrom:secretKeyRef:name:my-application-db-credentialskey:USER

  To get environement variable value fromSecret, where secret key being key of environment variable and value being value

  envFrom:database-credentials:type:secretnameSuffix:db-credentials

  You can either providenameSuffix which means name added after prefix<applicationName>- or static name withname of secret.

  You can specify whether the secret is mandatory or optional for the pod to start with theoptional: true/false value.

  Note: first key afterenvFrom is just used to uniquely identify different objects inenvFrom block. Make sure to keep it unique and relevant.

To disable liveness or readiness probe, set value ofenabled tofalse.

livenessProbe:enabled:false

By default probe handler type ishttpGet. You just need to overrideport andpath as per your need.

livenessProbe:enabled:truehttpGet:path:'/path'port:8080

In order to useexec handler, you can define fieldlivenessProbe.exec in your values.yaml.

livenessProbe:enabled:trueexec:command:      -cat      -/tmp/healthy