Application

Generic helm chart for applications which are:

• stateless
• create 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 or cronjob

Installing the Chart

To install the chart with the release name my-application in namespace test:

helm repo add stakater https://stakater.github.io/stakater-charts
helm repo update
helm install my-application stakater/application --namespace test

Uninstall the Chart

To uninstall the chart:

helm delete <name-of-the-chart>

Paramaters

Name	Description	Value
applicationName	Name of the application	application
namespaceOverride	Override default release namespace with a custom value	application
labels.group	Label to define application group	com.stakater.platform
labels.team	Label to define team	stakater

Deployment Paramaters

Name	Description	Value
deployment.enabled	Enable deployment on helm chart deployments	true
deployment.strategy	Strategy for updating deployments	RollingUpdate
deployment.reloadOnChange	Reload deployment if configMap/secret mounted are updated	true
deployment.nodeSelector	Select node to deploy this application	{}
deployment.hostAliases	Adding entries to a Pod's /etc/hosts file provides Pod-level override of hostname resolution when DNS and other options are not applicable	[]
deployment.additionalLabels	Additional labels for Deployment	{}
deployment.podLabels	Additional label added on pod which is used in Service's Label Selector	{}
deployment.annotations	Annotations on deployments	{}
deployment.additionalPodAnnotations	Additional Pod Annotations added on pod created by this Deployment	{}
deployment.replicas	Replicas to be created	``
deployment.imagePullSecrets	Secrets used to pull image	""
deployment.env	Environment variables to be passed to the app container	{}
deployment.volumes	Volumes to be added to the pod	{}
deployment.volumeMounts	Mount path for Volumes	{}
deployment.command	Command for primary container of deployment	[]
deployment.args	Arg for primary container of deployment	[]
deployment.tolerations	Taint tolerations for nodes	[]
deployment.affinity	Affinity for pod/node	[]
deployment.topologySpreadConstraints	Topology spread constraints definitions	[]
deployment.ports	Ports for primary container	[]
deployment.securityContext	Security Context for the pod	{}
deployment.additionalContainers	Add additional containers besides init and app containers	[]
deployment.containerSecurityContext	Add security context at container level	{}

Deployment Resources Parameters

Name	Description	Value
deployment.resources	Application pod resource requests & limits	See below

Requests and Limits

  resources: 
    limits:
      memory: 256Mi
      cpu: 0.5
    requests:
      memory: 128Mi
      cpu: 0.1

Deployment InitContainers Parameters

Name	Description	Value
deployment.initContainers	Init containers which runs before the app container	{}

Deployment fluentd Parameters

Name	Description	Value
deployment.fluentdConfigAnnotations	Annotations for fluentd Configurations	{}

Deployment Image Parameters

Name	Description	Value
deployment.image.repository	Image repository for the application	repository/image-name
deployment.image.tag	Tag of the application image	null
deployment.image.digest	Digest of the application image	``
deployment.image.pullPolicy	Pull policy for the application image	IfNotPresent

Deployment envFrom Parameters

Name	Description	Value
deployment.envFrom	Environment variables to be picked from configmap or secret	{}
deployment.envFrom.type	Type of data i.e. Configmap or Secret	``
deployment.envFrom.name	Name of Configmap or Secret, if set empty, set to application name	``
deployment.envFrom.nameSuffix	Suffix Name of Configmap or Secret, applicationName is appended as prefix	``

Deployment Probes Paramaters

Startup Probe

StartupProbe indicates that the Pod has successfully initialized. If specified, no other probes are executed until this completes successfully.

Name	Description	Value
deployment.startupProbe.enabled	Enabled startup probe	false
deployment.startupProbe.failureThreshold	When a probe fails, Kubernetes will try failureThreshold times before giving up.	30
deployment.startupProbe.periodSeconds	Perform probe everytime after specified periodSeconds	10
deployment.startupProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.
deployment.startupProbe.timeoutSeconds	Number of seconds after which the probe times out.
deployment.startupProbe.httpGet	Describes an action based on HTTP Get requests	path: '/path' port: 8080
deployment.startupProbe.exec	Kubelet executes the specified command to perform the probe	{}

Readiness Probe

Periodic probe of container service readiness. Container will be removed from service endpoints if the probe fails.

Name	Description	Value
deployment.readinessProbe.enabled	Enabled readiness probe	true
deployment.readinessProbe.failureThreshold	When a probe fails, Kubernetes will try failureThreshold times before giving up.	3
deployment.readinessProbe.periodSeconds	Perform probe everytime after specified periodSeconds	10
deployment.readinessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
deployment.readinessProbe.timeoutSeconds	Number of seconds after which the probe times out.	1
deployment.readinessProbe.initialDelaySeconds	Number of seconds after the container has started before liveness or readiness probes are initiated.	10
deployment.readinessProbe.httpGet	Describes an action based on HTTP Get requests	path: '/path' port: 8080
deployment.readinessProbe.exec	Kubelet executes the specified command to perform the probe	{}

Liveness Probe

Periodic probe of container liveness. Container will be restarted if the probe fails.

Name	Description	Value
deployment.livenessProbe.enabled	Enabled livenessProbe probe	true
deployment.livenessProbe.failureThreshold	When a probe fails, Kubernetes will try failureThreshold times before giving up.	3
deployment.livenessProbe.periodSeconds	Perform probe everytime after specified periodSeconds	10
deployment.livenessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
deployment.livenessProbe.timeoutSeconds	Number of seconds after which the probe times out.	1
deployment.livenessProbe.initialDelaySeconds	Number of seconds after the container has started before liveness or readiness probes are initiated.	10
deployment.livenessProbe.httpGet	Describes an action based on HTTP Get requests	path: '/path' port: 8080
deployment.livenessProbe.exec	Kubelet executes the specified command to perform the probe	{}

Deployment OpenshiftOAuthProxy Paramaters

Name	Description	Value
deployment.openshiftOAuthProxy.enabled	Add Openshift OAuth Proxy as SideCar Container	false
deployment.openshiftOAuthProxy.port	Application port so proxy should forward to this port	8080
deployment.openshiftOAuthProxy.secretName	Secret name containing the TLS cert	openshift-oauth-proxy-tls
deployment.openshiftOAuthProxy.image	image for oauth sidecar container	openshift/oauth-proxy:latest
deployment.openshiftOAuthProxy.disableTLSArg	If disabled --http-address=:8081 will be used instead of --https-address=:8443	false

Deployment Dns Paramaters

Name	Description	Value
deployment.dnsConfig	Enable pod disruption budget	{}

PodDisruptionBudget Paramaters

Name	Description	Value
pdb.enabled	Enable pod disruption budget	false
pdb.minAvailable	The number of pods that must be available after the eviction. If both minAvailable and maxUnavailable is set, minAvailable is preferred	1
pdb.maxUnavailable	The number of pods that can be unavailable after the eviction. Either minAvailable or maxUnavailable needs to be provided	``

Persistence Paramaters

Name	Description	Value
persistence.enabled	Enable persistence	false
persistence.mountPVC	Whether to mount the created PVC to the deployment	false
persistence.mountPath	If persistence.mountPVC is set, so where to mount the volume in the deployment	/
persistence.name	Name of the PVC.	``
persistence.accessMode	Access mode for volume	ReadWriteOnce
persistence.storageClass	StorageClass of the volume	-
persistence.additionalLabels	Additional labels for persistent volume	{}
persistence.annotations	Annotations for persistent volume	{}
persistence.storageSize	Size of the persistent volume	8Gi
persistence.volumeName	Name of the volume	``
persistence.volumeMode	PVC volume mode	``

Service Paramaters

Name	Description	Value
service.enabled	Enable service in helm chart	true
service.additionalLabels	Additional labels for service	{}
service.annotations	Annotations for service	{}
service.ports	Ports for applications service	- port: 8080   name: http   protocol: TCP   targetPort: 8080
service.type	Type of service	ClusterIP

Ingress Paramaters

Name	Description	Value
ingress.enabled	Enable ingress	false
ingress.hosts	Array of hosts to be served by this ingress.	[]
ingress.hosts[].host	Host to be served. See example.	[]
ingress.hosts[].paths	Paths against the host. If not specified, default configuration is added, See example.	[]
ingress.additionalLabels	Labels for ingress	{}
ingress.annotations	Annotations for ingress	{}
ingress.tls	TLS block for ingress	[]
ingress.ingressClassName	Name of the ingress class	''

Route Paramaters

Name	Description	Value
route.enabled	Enable Route incase of Openshift	false
route.host	Host of route. If no host is added then openshift inserts the default hostname	nil
route.annotations	Annotations for route	{}
route.additionalLables	Labels for route	{}
route.port.targetPort	Port of the service that serves pods	http
route.wildcardPolicy	Route wildcard policy	None
route.tls.termination	TLS termination strategy	edge
route.tls.insecureEdgeTerminationPolicy	TLS termination policy for insecure traffic	Redirect
route.path	path of route traffic
route.to.weight	portion of requests to be handled by the service	100
route.alternateBackends	For the purpose of multiple services supporting a route
route.alternateBackends.kind	Kind of supporting resource	Service
route.alternateBackends.name	Name of supporting service
route.alternateBackends.weight	portion of requests to be handled by supporting service

Forecastle Paramaters

Stakater Forecastle parameters

Name	Description	Value
forecastle.enabled	Enable Forecastle	false
forecastle.additionalLabels	Additional labels for Forecastle Custom Resource	{}
forecastle.icon	URL of application icon display on forecastle dashboard	https://raw.githubusercontent.com/stakater/ForecastleIcons/master/stakater-big.png
forecastle.displayName	Name of the application to be displayed on Forecastle dashboard	application
forecastle.group	Group application on Forecastle dashboard	if not defined Namespace name is used
forecastle.properties	Additional properties for Custom Resource	{}
forecastle.networkRestricted	Whether app is network restricted or not	false

RBAC Paramaters

Name	Description	Value
rbac.enabled	Enable RBAC	true
rbac.serviceAccount.enabled	Enable serviceAccount	false
rbac.serviceAccount.name	Name of the existing serviceAccount	""
rbac.serviceAccount.additionalLabels	Labels for serviceAccount	{}
rbac.serviceAccount.annotations	Annotations for serviceAccount	{}
rbac.roles	Array of roles	[]

ConfigMap Paramaters

Name	Description	Value
configMap.enabled	Enable configMaps	false
configMap.additionalLabels	Labels for configMaps	{}
configMap.annotations	Annotations for configMaps	{}
configMap.files	Map of configMap files with suffixes and data contained in those files	{}

Secret Paramaters

Name	Description	Value
secret.enabled	Enable secret	false
secret.additionalLabels	Labels for secret	{}
secret.annotations	Annotations for secret	{}
secret.files	Map of secret files with suffixes and data contained in those files	{}

ServiceMonitor Paramaters

Name	Description	Value
serviceMonitor.enabled	Enable serviceMonitor	false
serviceMonitor.additionalLabels	Labels for serviceMonitor	{}
serviceMonitor.annotations	Annotations for serviceMonitor	{}
serviceMonitor.jobLabel	Job Label used for application selector	k8s-app
serviceMonitor.endpoints	Array of endpoints to be scraped by prometheus	- interval: 5s   path: /actuator/prometheus   port: http

Autoscaling Paramaters

Name	Description	Value
autoscaling.enabled	Enable horizontal pod autoscaler	false
autoscaling.additionalLabels	Labels for horizontal pod autoscaler	{}
autoscaling.annotations	Annotations for horizontal pod autoscaler	{}
autoscaling.minReplicas	Sets minimum replica count when autoscaling is enabled	1
autoscaling.maxReplicas	Sets maximum replica count when autoscaling is enabled	10
autoscaling.metrics	Configuration for hpa metrics, set when autoscaling is enabled	{}

EndpointMonitor Paramaters

Stakater IngressMonitorController EndpointMonitor parameters

Name	Description	Value
endpointMonitor.enabled	Enable endpointMonitor for IMC (https://github.com/stakater/IngressMonitorController)	false
endpointMonitor.additionalLabels	Labels for endpointMonitor	{}
endpointMonitor.annotations	Annotations for endpointMonitor	{}
endpointMonitor.additionalConfig	Additional Config for endpointMonitor	{}

SealedSecret Paramaters

Name	Description	Value
sealedSecret.enabled	Enable sealed secret	false
sealedSecret.additionalLabels	Labels for sealed secret	{}
sealedSecret.annotations	Annotations that apply to all sealed secrets created under files	{}
sealedSecret.files	Map of secret files with name and encrypted data contained in those files	{}
sealedSecret.files.[name].annotations	Annotations that apply to the secret created through sealed secret	{}
sealedSecret.files.[name].labels	Labels that apply to the secret created through sealed secret	{}
sealedSecret.files.[name].type	Type of secret created through sealed secret	Opaque
sealedSecret.files.[name].clusterWide	When set to true, adds annotation sealedsecrets.bitnami.com/cluster-wide: true to the secret created through sealed secret, setting the scope of the secret to cluster wide.	false

Cert-manager Certificate Paramaters

Name	Description	Value
certificate.enabled	Enable Certificate Custom Resource	false
certificate.enabled	Enable Certificate Custom Resource	false
certificate.additionalLabels	Additional labels for Certificate Custom Resource	{}
certificate.annotations	Annotations for Certificate Custom Resource	{}
certificate.secretName	SecretName is the name of the secret resource that will be automatically created and managed by this Certificate resource	tls-cert
certificate.duration	The requested ‘duration’ (i.e. lifetime) of the Certificate	8760h0m0s
certificate.renewBefore	The amount of time before the currently issued certificate’s notAfter time that cert-manager will begin to attempt to renew the certificate	720h0m0s
certificate.subject	Full X509 name specification for certificate	{}
certificate.commonName	CommonName is the common name as specified on the DER encoded CSR	admin-app
certificate.keyAlgorithm	KeyAlgorithm is the private key algorithm of the corresponding private key for this certificate	rsa
certificate.keyEncoding	KeyEncoding is the private key cryptography standards (PKCS) for this certificate’s private key to be encoded in	pkcs1
certificate.keySize	KeySize is the key bit size of the corresponding private key for this certificate	2048
certificate.isCA	IsCA will mark this Certificate as valid for certificate signing	false
certificate.usages	Usages is the set of x509 usages that are requested for the certificate	{}
certificate.dnsNames	DNSNames is a list of DNS subjectAltNames to be set on the Certificate.	{}
certificate.ipAddresses	IPAddresses is a list of IP address subjectAltNames to be set on the Certificate.	{}
certificate.uriSANs	URISANs is a list of URI subjectAltNames to be set on the Certificate.	{}
certificate.emailSANs	EmailSANs is a list of email subjectAltNames to be set on the Certificate.	{}
certificate.privateKey.enabled	Enable private key for the certificate	false
certificate.privateKey.rotationPolicy	Denotes how private keys should be generated or sourced when a Certificate is being issued.	Always
certificate.issuerRef.name	IssuerRef is a reference to the issuer for this certificate. Name of the resource being referred to	ca-issuer
certificate.issuerRef.kind	Kind of the resource being referred to	ClusterIssuer
certificate.keystores.enabled	Enables keystore configuration. Keystores configures additional keystore output formats stored in the secretName Secret resource	false
certificate.keystores.pkcs12.create	Enables PKCS12 keystore creation for the Certificate. PKCS12 configures options for storing a PKCS12 keystore in the spec.secretName Secret resource	true
certificate.keystores.pkcs12.key	The key of the entry in the Secret resource’s data field to be used	test_key
certificate.keystores.pkcs12.name	The name of the Secret resource being referred to	test-creds
certificate.keystores.jks.create	Enables jks keystore creation for the Certificate. JKS configures options for storing a JKS keystore in the spec.secretName Secret resource	false
certificate.keystores.jks.key	The key of the entry in the Secret resource’s data field to be used	test_key
certificate.keystores.jks.name	The name of the Secret resource being referred to	test-creds

Alertmanager Config Paramaters

Name	Description	Value
alertmanagerConfig.enabled	Enable alertmanagerConfig for this app (Will be merged in the base config)	false
alertmanagerConfig.selectionLabels	Labels for this config to be selected for merging in alertmanager base config	alertmanagerConfig: "workload"
alertmanagerConfig.spec.route	The Alertmanager route definition for alerts matching the resource’s namespace. It will be added to the generated Alertmanager configuration as a first-level route	{}
alertmanagerConfig.spec.receivers	List of receivers	[]
alertmanagerConfig.spec.inhibitRules	InhibitRule defines an inhibition rule that allows to mute alerts when other alerts are already firing	[]

PrometheusRule Paramaters

Name	Description	Value
prometheusRule.enabled	Enable prometheusRule for this app	false
prometheusRule.additionalLabels	Kubernetes labels object, these additional labels will be added to PrometheusRule CRD	{}
prometheusRule.spec.groups	PrometheusRules in their groups to be added	[]

SecretProviderClass Paramaters

Name	Description	Value
secretProviderClass.enabled	Enables Secret Provider Class Custom Resource	false
secretProviderClass.name	Name of Secret Provider Class Custom Resource	""
secretProviderClass.provider	Provider of Secret Provider Class Custom Resource	""
secretProviderClass.vaultAddress	Address of vault	""
secretProviderClass.roleName	Name of the role being referred to in vault	""
secretProviderClass.objects	The object created from the secret in vault	[]
secretProviderClass.secretObjects	This creates the kubernetes secret	""

ExternalSecret Paramaters

Name	Description	Value
externalSecret.enabled	Enables External Secret Custom Resource	false
externalSecret.secretStore.name	Defines name of default SecretStore to use when fetching the secret data	tenant-vault-secret-store
externalSecret.secretStore.kind	Defines kind as SecretStore or ClusterSecretStore	SecretStore
externalSecret.refreshInterval	Amount of time before the values reading again from the SecretStore provider	1m
externalSecret.files	Array of secret files with name and remote reference data contained in those files	[]

NetworkPolicy Paramaters

Name	Description	Value
networkPolicy.enabled	Enable NetworkPolicy	false
networkPolicy.additionalLabels	Kubernetes labels object	{}
networkPolicy.annotations	Annotations for NetworkPolicy	{}
networkPolicy.ingress	Ingress ruels for NetworkPolicy	[]
networkPolicy.egress	egress rules for NetworkPolicy	[]

Grafana Dashboard Paramaters

Name	Description	Value
grafanaDashboard.enabled	Enables Grafana Dashboard	false
grafanaDashboard.additionalLabels	Kubernetes labels object	{}
grafanaDashboard.annotations	Annotations for Grafana Dashboard	{}
grafanaDashboard.contents.key	Used as name of Grafana Dashboard object	""
grafanaDashboard.contents.key.json	json string used as content of Grafana Dashboard object	""
grafanaDashboard.contents.key.url	Url used to fetch dashboard content. According to GrafanaDashboard behavior, if both url and json are specified then the GrafanaDashboard content will be updated with fetched content from url	""

CronJob Parameters

Name	Description	Value
cronJob.enabled	Enable cronjob in application chart	""
cronJob.jobs	cronjobs spec	{}

Job paramater for each cronjob object at cronJob.jobs

Name	Description
<name>.schedule	Schedule of cronjob
<name>.image.repository	Repository of container image of cronjob
<name>.image.tag	Tag of container image of cronjob
<name>.image.digest	Digest of container image of cronjob
<name>.image.imagePullPolicy	ImagePullPolicy of container image ofcronjob
<name>.command	Command of container of job
<name>.args	Args of container of job
<name>.resources	Resources of container of job
<name>.additionalLabels	Additional labels of cronjob
<name>.annotations	Annotation of cronjob
<name>.successfulJobsHistoryLimit	Successful jobs historyLimit of cronjob
<name>.concurrencyPolicy	ConcurrencyPolicy of cronjob
<name>.failedJobsHistoryLimit	FailedJobsHistoryLimit of cronjob
<name>.volumeMounts	Volume mounts of cronjob
<name>.volumes	Volumes of cronjob
<name>.nodeSelector	Node selector of cronjob
<name>.affinity	Affinity of cronjob
<name>.tolerations	Tolerations of cronjob
<name>.restartPolicy	RestartPolicy of cronjob
<name>.imagePullSecrets	ImagePullSecrets of cronjob

Naming convention for ConfigMap, Secret, SealedSecret and ExternalSecret

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 in secret.files,configMap.files, sealedSecret.files and externalSecret.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 helloworld-config

Consuming environment variable in application chart

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

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

   env:
      KEY:
        value: MY_VALUE
  

• To get environement variable value from ConfigMap

  Suppose we have configmap created from applicaion chart

  applicationName: my-application
  configMap:
    enabled: true
    files:
      application-config:
        LOG: DEBUG
        VERBOSE: 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-appication-config
        key: LOG
  

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

    envFrom:
     application-config-env:
       type: configmap
       nameSuffix: application-config
  

  you can either provide nameSuffix which means name added after prefix <applicationName>- or static name with name of configmap.

• To get environment variable value from Secret

  Suppose we have secret created from application chart

   applicationName: my-application
   secret:
     enabled: true
     files:
        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-credentials
           key: USER
  

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

  envFrom:
    database-credentials:
       type: secret
       nameSuffix: db-credentials
  

  you can either provide nameSuffix which means name added after prefix <applicationName>- or static name with name of secret

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

Configuring probes

To disable liveness or readiness probe, set value of enabled to false.

  livenessProbe:
    enabled: false

By default probe handler type is httpGet. You just need to override port and path as per your need.

  livenessProbe:
    enabled: true
    httpGet:
      path: '/path'
      port: 8080

In order to use exec handler, you can define field livenessProbe.exec in your values.yaml.

  livenessProbe:
    enabled: true
    exec:
      command:
        - cat
        - /tmp/healthy