charts/bitnami/tomcat

Tomcat

Apache Tomcat, often referred to as Tomcat, is an open-source web server and servlet container developed by the Apache Software Foundation. Tomcat implements several Java EE specifications including Java Servlet, JavaServer Pages, Java EL, and WebSocket, and provides a "pure Java" HTTP web server environment for Java code to run in.

TL;DR

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/tomcat

Introduction

This chart bootstraps a Tomcat deployment on a Kubernetes cluster using the Helm package manager.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.

Prerequisites

• Kubernetes 1.12+
• Helm 3.1.0
• PV provisioner support in the underlying infrastructure
• ReadWriteMany volumes for deployment scaling

Installing the Chart

To install the chart with the release name my-release:

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/tomcat

These commands deploy Tomcat on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.

Tip

: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Parameters

Global parameters

Name	Description	Value
global.imageRegistry	Global Docker image registry	""
global.imagePullSecrets	Global Docker registry secret names as an array	[]
global.storageClass	Global StorageClass for Persistent Volume(s)	""

Common parameters

Name	Description	Value
kubeVersion	Force target Kubernetes version (using Helm capabilities if not set)	""
nameOverride	String to partially override common.names.fullname template (will maintain the release name)	""
fullnameOverride	String to fully override common.names.fullname template	""
commonLabels	Add labels to all the deployed resources	{}
commonAnnotations	Add annotations to all the deployed resources	{}
clusterDomain	Kubernetes Cluster Domain	cluster.local
extraDeploy	Array of extra objects to deploy with the release	[]

Tomcat parameters

Name	Description	Value
image.registry	Tomcat image registry	docker.io
image.repository	Tomcat image repository	bitnami/tomcat
image.tag	Tomcat image tag (immutable tags are recommended)	10.0.12-debian-10-r14
image.pullPolicy	Tomcat image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[]
image.debug	Specify if debug logs should be enabled	false
hostAliases	Deployment pod host aliases	[]
tomcatUsername	Tomcat admin user	user
tomcatPassword	Tomcat admin password	""
tomcatAllowRemoteManagement	Enable remote access to management interface	0
catalinaOpts	Java runtime option used by tomcat JVM	""
command	Override default container command (useful when using custom images)	[]
args	Override default container args (useful when using custom images)	[]
extraEnvVars	Extra environment variables to be set on Tomcat container	[]
extraEnvVarsCM	Name of existing ConfigMap containing extra environment variables	""
extraEnvVarsSecret	Name of existing Secret containing extra environment variables	""

Tomcat deployment parameters

Name	Description	Value
replicaCount	Specify number of Tomcat replicas	1
deployment.type	Use Deployment or StatefulSet	deployment
updateStrategy.type	StrategyType	RollingUpdate
containerPort	HTTP port to expose at container level	8080
containerExtraPorts	Extra ports to expose at container level	{}
podSecurityContext.enabled	Enable Tomcat pods' Security Context	true
podSecurityContext.fsGroup	Set Tomcat pod's Security Context fsGroup	1001
containerSecurityContext.enabled	Enable Tomcat containers' SecurityContext	true
containerSecurityContext.runAsUser	User ID for the Tomcat container	1001
resources.limits	The resources limits for the Tomcat container	{}
resources.requests	The requested resources for the Tomcat container	{}
livenessProbe.enabled	Enable livenessProbe	true
livenessProbe.httpGet.path	Request path for livenessProbe	/
livenessProbe.httpGet.port	Port for livenessProbe	http
livenessProbe.initialDelaySeconds	Initial delay seconds for livenessProbe	120
livenessProbe.periodSeconds	Period seconds for livenessProbe	10
livenessProbe.timeoutSeconds	Timeout seconds for livenessProbe	5
livenessProbe.failureThreshold	Failure threshold for livenessProbe	6
livenessProbe.successThreshold	Success threshold for livenessProbe	1
readinessProbe.enabled	Enable readinessProbe	true
readinessProbe.httpGet.path	Request path for readinessProbe	/
readinessProbe.httpGet.port	Port for readinessProbe	http
readinessProbe.initialDelaySeconds	Initial delay seconds for readinessProbe	30
readinessProbe.periodSeconds	Period seconds for readinessProbe	5
readinessProbe.timeoutSeconds	Timeout seconds for readinessProbe	3
readinessProbe.failureThreshold	Failure threshold for readinessProbe	3
readinessProbe.successThreshold	Success threshold for readinessProbe	1
customLivenessProbe	Override default liveness probe	{}
customReadinessProbe	Override default readiness probe	{}
podLabels	Extra labels for Tomcat pods	{}
podAnnotations	Annotations for Tomcat pods	{}
podAffinityPreset	Pod affinity preset. Ignored if affinity is set. Allowed values: soft or hard	""
podAntiAffinityPreset	Pod anti-affinity preset. Ignored if affinity is set. Allowed values: soft or hard	soft
nodeAffinityPreset.type	Node affinity preset type. Ignored if affinity is set. Allowed values: soft or hard	""
nodeAffinityPreset.key	Node label key to match. Ignored if affinity is set.	""
nodeAffinityPreset.values	Node label values to match. Ignored if affinity is set.	[]
affinity	Affinity for pod assignment. Evaluated as a template.	{}
nodeSelector	Node labels for pod assignment. Evaluated as a template.	{}
tolerations	Tolerations for pod assignment. Evaluated as a template.	[]
topologySpreadConstraints	Topology Spread Constraints for pod assignment spread across your cluster among failure-domains. Evaluated as a template	[]
extraPodSpec	Optionally specify extra PodSpec	{}
extraVolumes	Optionally specify extra list of additional volumes for Tomcat pods in Deployment	[]
extraVolumeClaimTemplates	Optionally specify extra list of additional volume claim templates for Tomcat pods in StatefulSet	[]
extraVolumeMounts	Optionally specify extra list of additional volumeMounts for Tomcat container(s)	[]
initContainers	Add init containers to the Tomcat pods.	[]
sidecars	Add sidecars to the Tomcat pods.	[]
persistence.enabled	Enable persistence	true
persistence.storageClass	PVC Storage Class for Tomcat volume	""
persistence.annotations	Persistent Volume Claim annotations	{}
persistence.accessModes	PVC Access Modes for Tomcat volume	["ReadWriteOnce"]
persistence.size	PVC Storage Request for Tomcat volume	8Gi
persistence.existingClaim	An Existing PVC name for Tomcat volume	""
persistence.selectorLabels	Selector labels to use in volume claim template in statefulset	{}

Traffic Exposure parameters

Name	Description	Value
service.type	Kubernetes Service type	LoadBalancer
service.port	Service HTTP port	80
service.nodePort	Kubernetes http node port	""
service.loadBalancerIP	Port Use serviceLoadBalancerIP to request a specific static IP, otherwise leave blank	""
service.externalTrafficPolicy	Enable client source IP preservation	Cluster
service.annotations	Annotations for Tomcat service	{}
ingress.enabled	Enable ingress controller resource	false
ingress.hostname	Default host for the ingress resource	tomcat.local
ingress.annotations	Additional annotations for the Ingress resource. To enable certificate autogeneration, place here your cert-manager annotations.	{}
ingress.tls	Enable TLS configuration for the hostname defined at ingress.hostname parameter	false
ingress.extraHosts	The list of additional hostnames to be covered with this ingress record.	[]
ingress.extraTls	The tls configuration for additional hostnames to be covered with this ingress record.	[]
ingress.secrets	If you're providing your own certificates, please use this to add the certificates as secrets	[]
ingress.apiVersion	Force Ingress API version (automatically detected if not set)	""
ingress.path	Ingress path	/
ingress.pathType	Ingress path type	ImplementationSpecific

Volume Permissions parameters

Name	Description	Value
volumePermissions.enabled	Enable init container that changes volume permissions in the data directory	false
volumePermissions.image.registry	Init container volume-permissions image registry	docker.io
volumePermissions.image.repository	Init container volume-permissions image repository	bitnami/bitnami-shell
volumePermissions.image.tag	Init container volume-permissions image tag	10-debian-10-r225
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	IfNotPresent
volumePermissions.image.pullSecrets	Specify docker-registry secret names as an array	[]
volumePermissions.resources.limits	Init container volume-permissions resource limits	{}
volumePermissions.resources.requests	Init container volume-permissions resource requests	{}

Metrics parameters

Name	Description	Value
metrics.jmx.enabled	Whether or not to expose JMX metrics to Prometheus	false
metrics.jmx.catalinaOpts	custom option used to enabled JMX on tomcat jvm evaluated as template	-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=5555 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.local.only=true
metrics.jmx.image.registry	JMX exporter image registry	docker.io
metrics.jmx.image.repository	JMX exporter image repository	bitnami/jmx-exporter
metrics.jmx.image.tag	JMX exporter image tag (immutable tags are recommended)	0.16.1-debian-10-r73
metrics.jmx.image.pullPolicy	JMX exporter image pull policy	IfNotPresent
metrics.jmx.image.pullSecrets	Specify docker-registry secret names as an array	[]
metrics.jmx.config	Configuration file for JMX exporter	""
metrics.jmx.resources.limits	JMX Exporter container resource limits	{}
metrics.jmx.resources.requests	JMX Exporter container resource requests	{}
metrics.jmx.ports.metrics	JMX Exporter container metrics ports	5556
metrics.jmx.existingConfigmap	Name of existing ConfigMap with JMX exporter configuration	""
metrics.podMonitor.podTargetLabels	Used to keep given pod's labels in target	[]
metrics.podMonitor.enabled	Create PodMonitor Resource for scraping metrics using PrometheusOperator	false
metrics.podMonitor.namespace	Namespace in which Prometheus is running	monitoring
metrics.podMonitor.interval	Specify the interval at which metrics should be scraped	30s
metrics.podMonitor.scrapeTimeout	Specify the timeout after which the scrape is ended	30s
metrics.podMonitor.additionalLabels	Additional labels that can be used so PodMonitors will be discovered by Prometheus	{}
metrics.podMonitor.scheme	Scheme to use for scraping	http
metrics.podMonitor.tlsConfig	TLS configuration used for scrape endpoints used by Prometheus	{}
metrics.podMonitor.relabelings	Prometheus relabeling rules	[]

The above parameters map to the env variables defined in bitnami/tomcat. For more information please refer to the bitnami/tomcat image documentation.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install my-release \
  --set tomcatUser=manager,tomcatPassword=password bitnami/tomcat

The above command sets the Tomcat management username and password to manager and password respectively.

NOTE: Once this chart is deployed, it is not possible to change the application's access credentials, such as usernames or passwords, using Helm. To change these application credentials after deployment, delete any persistent volumes (PVs) used by the chart and re-deploy it, or use the application's built-in administrative tools if available.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

$ helm install my-release -f values.yaml bitnami/tomcat

Tip

: You can use the default values.yaml

Configuration and installation details

Rolling vs Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Use a different Tomcat version

To modify the application version used in this chart, specify a different version of the image using the image.tag parameter and/or a different repository using the image.repository parameter. Refer to the chart documentation for more information on these parameters and how to use them with images from a private registry.

Add extra environment variables

To add extra environment variables (useful for advanced operations like custom init scripts), use the extraEnvVars property.

extraEnvVars:
  - name: LOG_LEVEL
    value: DEBUG

Alternatively, define a ConfigMap or a Secret with the environment variables. To do so, use the extraEnvVarsCM or the extraEnvVarsSecret values.

Use Sidecars and Init Containers

If additional containers are needed in the same pod (such as additional metrics or logging exporters), they can be defined using the sidecars config parameter. Similarly, extra init containers can be added using the initContainers parameter.

Refer to the chart documentation for more information on, and examples of, configuring and using sidecars and init containers.

Set Pod affinity

This chart allows you to set custom Pod affinity using the affinity parameter. Find more information about Pod's affinity in the Kubernetes documentation.

As an alternative, use one of the preset configurations for pod affinity, pod anti-affinity, and node affinity available at the bitnami/common chart. To do so, set the podAffinityPreset, podAntiAffinityPreset, or nodeAffinityPreset parameters.

Persistence

The Bitnami Tomcat image stores the Tomcat data and configurations at the /bitnami/tomcat path of the container.

Persistent Volume Claims (PVCs) are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube.

See the Parameters section to configure the PVC or to disable persistence.

Adjust permissions of persistent volume mountpoint

As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it.

By default, the chart is configured to use Kubernetes Security Context to automatically change the ownership of the volume. However, this feature does not work in all Kubernetes distributions. As an alternative, this chart supports using an init container to change the ownership of the volume before mounting it in the final destination.

You can enable this init container by setting volumePermissions.enabled to true.

Troubleshooting

Find more information about how to deal with common errors related to Bitnami’s Helm charts in this troubleshooting guide.

Upgrading

To 8.0.0

• Chart labels were adapted to follow the Helm charts standard labels.
• Ingress configuration was also adapted to follow the Helm charts best practices.
• This version also introduces bitnami/common, a library chart as a dependency. More documentation about this new utility could be found here. Please, make sure that you have updated the chart dependencies before executing any upgrade.

Consequences:

• Backwards compatibility is not guaranteed. However, you can easily workaround this issue by removing Tomcat deployment before upgrading (the following example assumes that the release name is tomcat):

$ export TOMCAT_PASSWORD=$(kubectl get secret --namespace default tomcat -o jsonpath="{.data.tomcat-password}" | base64 --decode)
$ kubectl delete deployments.apps tomcat
$ helm upgrade tomcat bitnami/tomcat --set tomcatPassword=$TOMCAT_PASSWORD

To 7.0.0

On November 13, 2020, Helm v2 support formally ended. This major version is the result of the required changes applied to the Helm Chart to be able to incorporate the different features added in Helm v3 and to be consistent with the Helm project itself regarding the Helm v2 EOL.

Learn more about this change and related upgrade considerations.

To 5.0.0

This release updates the Bitnami Tomcat container to 9.0.26-debian-9-r0, which is based on Bash instead of Node.js.

To 2.1.0

Tomcat container was moved to a non-root approach. There shouldn't be any issue when upgrading since the corresponding securityContext is enabled by default. Both the container image and the chart can be upgraded by running the command below:

$ helm upgrade my-release bitnami/tomcat

If you use a previous container image (previous to 8.5.35-r26) disable the securityContext by running the command below:

$ helm upgrade my-release bitnami/tomcat --set securityContext.enabled=false,image.tag=XXX

To 1.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is tomcat:

$ kubectl patch deployment tomcat --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'