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 2.12+ or Helm 3.0-beta3+
• 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

The following tables lists the configurable parameters of the Tomcat chart and their default values.

Parameter	Description	Default
global.imageRegistry	Global Docker image registry	nil
global.imagePullSecrets	Global Docker registry secret names as an array	[] (does not add image pull secrets to deployed pods)
global.storageClass	Global storage class for dynamic provisioning	nil
image.registry	Tomcat image registry	docker.io
image.repository	Tomcat Image name	bitnami/tomcat
image.tag	Tomcat Image tag	{TAG_NAME}
image.pullPolicy	Tomcat image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
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 name	bitnami/minideb
volumePermissions.image.tag	Init container volume-permissions image tag	buster
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	Always
volumePermissions.resources	Init container resource requests/limit	{}
nameOverride	String to partially override tomcat.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override tomcat.fullname template with a string	nil
updateStrategy	Set to Recreate if you use persistent volume that cannot be mounted by more than one pods	RollingUpdate
tomcatUsername	Tomcat admin user	user
tomcatPassword	Tomcat admin password	random 10 character alphanumeric string
tomcatAllowRemoteManagement	Enable remote access to management interface	0 (disabled)
podAnnotations	Pod annotations	{}
affinity	Map of node/pod affinities	{} (The value is evaluated as a template)
nodeSelector	Node labels for pod assignment	{} (The value is evaluated as a template)
tolerations	Tolerations for pod assignment	[] (The value is evaluated as a template)
securityContext.enabled	Enable security context	true
securityContext.fsGroup	Group ID for the container	1001
securityContext.runAsUser	User ID for the container	1001
resources	CPU/Memory resource requests/limits	{"requests": {"Memory": "512Mi", CPU: "300m"}}
persistence.enabled	Enable persistence using PVC	true
persistence.storageClass	PVC Storage Class for Tomcat volume	nil (uses alpha storage class annotation)
persistence.accessMode	PVC Access Mode for Tomcat volume	ReadWriteOnce
persistence.size	PVC Storage Request for Tomcat volume	8Gi
service.type	Kubernetes Service type	LoadBalancer
service.port	Service HTTP port	80
service.nodePort	Kubernetes http node port	""
service.externalTrafficPolicy	Enable client source IP preservation	Cluster
service.loadBalancerIP	LoadBalancer service IP address	""
service.annotations	Service annotations	{}
ingress.enabled	Enable the ingress controller	false
ingress.certManager	Add annotations for certManager	false
ingress.annotations	Annotations to set in the ingress controller	{}
ingress.hosts[0].name	Hostname to your opencart installation	tomcat.local
ingress.hosts[0].path	Path within the url structure	/
ingress.hosts[0].tls	Utilize TLS backend in ingress	false
ingress.hosts[0].tlsHosts	Array of TLS hosts for ingress record (defaults to ingress.hosts[0].name if nil)	nil
ingress.hosts[0].tlsSecret	TLS Secret (certificates)	tomcat.local-tls

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.

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.

Change Tomcat version

To modify the Tomcat version used in this chart you can specify a valid image tag using the image.tag parameter. For example, image.tag=X.Y.Z. This approach is also applicable to other images like exporters.

Persistence

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

Persistent Volume Claims 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 initContainer to change the ownership of the volume before mounting it in the final destination.

You can enable this initContainer by setting volumePermissions.enabled to true.

Notable changes

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.

Upgrading

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=fase,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"}]'