bitnami/tomcat

Chart version: 8.1.0
Api version: v2
App version: 9.0.41
Chart for Apache Tomcat
application
Chart Type
Active
Status
Unknown
License
20145
Downloads
https://charts.bitnami.com/bitnami
Set me up:
helm repo add center https://repo.chartcenter.io
Install Chart:
helm install tomcat center/bitnami/tomcat
Versions (0)

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 3.0-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 per section/component:

Global parameters

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

Common parameters

Parameter Description Default
nameOverride String to partially override common.names.fullname nil
fullnameOverride String to fully override common.names.fullname nil
commonLabels Labels to add to all deployed objects {}
commonAnnotations Annotations to add to all deployed objects {}
clusterDomain Default Kubernetes cluster domain cluster.local
extraDeploy Array of extra objects to deploy with the release [] (evaluated as a template)
kubeVersion Force target Kubernetes version (using Helm capabilities if not set) nil

Tomcat parameters

Parameter Description Default
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)
image.debug Specify if debug logs should be enabled false
tomcatUsername Tomcat admin user user
tomcatPassword Tomcat admin password random 10 character alphanumeric string
tomcatAllowRemoteManagement Enable remote access to management interface 0 (disabled)
command Override default container command (useful when using custom images) nil
args Override default container args (useful when using custom images) nil
extraEnvVars Extra environment variables to be set on Tomcat container {}
extraEnvVarsCM Name of existing ConfigMap containing extra env vars nil
extraEnvVarsSecret Name of existing Secret containing extra env vars nil

Tomcat deployment parameters

Parameter Description Default
replicaCount Specify number of Tomcat replicas 1
containerPort HTTP port to expose at container level 8080
podSecurityContext Tomcat pods’ Security Context Check values.yaml file
containerSecurityContext Tomcat containers’ Security Context Check values.yaml file
resources.limits The resources limits for the Tomcat container {}
resources.requests The requested resources for the Tomcat container {"memory": "512Mi", "cpu": "300m"}
livenessProbe Liveness probe configuration for Tomcat Check values.yaml file
readinessProbe Readiness probe configuration for Tomcat Check values.yaml file
customLivenessProbe Override default liveness probe nil
customReadinessProbe Override default readiness probe nil
updateStrategy Strategy to use to update Pods Check values.yaml file
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)
podLabels Extra labels for Tomcat pods {} (evaluated as a template)
podAnnotations Annotations for Tomcat pods {} (evaluated as a template)
extraVolumeMounts Optionally specify extra list of additional volumeMounts for Tomcat container(s) []
extraVolumes Optionally specify extra list of additional volumes for Tomcat pods []
initContainers Add additional init containers to the Tomcat pods {} (evaluated as a template)
sidecars Add additional sidecar containers to the Tomcat pods {} (evaluated as a template)
persistence.enabled Enable persistence using PVC true
persistence.storageClass PVC Storage Class for Tomcat volume nil (uses alpha storage class annotation)
persistence.existingClaim An Existing PVC name 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

Exposure parameters

Parameter Description Default
service.type Kubernetes Service type LoadBalancer
service.port Service HTTP port 80
service.nodePort Kubernetes http node port ""
service.loadBalancerIP Kubernetes LoadBalancerIP to request nil
service.externalTrafficPolicy Enable client source IP preservation Cluster
service.annotations Annotations for Tomcat service {} (evaluated as a template)
ingress.enabled Enable ingress controller resource false
ingress.apiVersion Force Ingress API version (automatically detected if not set)
ingress.path Ingress path /
ingress.pathType Ingress path type ImplementationSpecific
ingress.certManager Add annotations for cert-manager false
ingress.hostname Default host for the ingress resource tomcat.local
ingress.tls Enable TLS configuration for the hostname defined at ingress.hostname parameter false
ingress.annotations Ingress annotations {} (evaluated as a template)
ingress.extraHosts[0].name Additional hostnames to be covered nil
ingress.extraHosts[0].path Additional hostnames to be covered nil
ingress.extraTls[0].hosts[0] TLS configuration for additional hostnames to be covered nil
ingress.extraTls[0].secretName TLS configuration for additional hostnames to be covered nil
ingress.secrets[0].name TLS Secret Name nil
ingress.secrets[0].certificate TLS Secret Certificate nil
ingress.secrets[0].key TLS Secret Key nil

Volume Permissions parameters

Parameter Description Default
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.image.pullSecrets Specify docker-registry secret names as an array [] (does not add image pull secrets to deployed pods)
volumePermissions.resources.limits Init container volume-permissions resource limits {}
volumePermissions.resources.requests Init container volume-permissions resource requests {}

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.

Adding extra environment variables

In case you want to add extra environment variables (useful for advanced operations like custom init scripts), you can use the extraEnvVars property.

extraEnvVars:
  - name: LOG_LEVEL
    value: DEBUG

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

Sidecars and Init Containers

If you have a need for additional containers to run within the same pod as the Tomcat app (e.g. an additional metrics or logging exporter), you can do so via the sidecars config parameter. Simply define your container according to the Kubernetes container spec.

sidecars:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
       containerPort: 1234

Similarly, you can add extra init containers using the initContainers parameter.

initContainers:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
        containerPort: 1234

Setting Pod’s affinity

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

As an alternative, you can use 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.

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 was formally finished, 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.

What changes were introduced in this major version?

  • Previous versions of this Helm Chart use apiVersion: v1 (installable by both Helm 2 and 3), this Helm Chart was updated to apiVersion: v2 (installable by Helm 3 only). Here you can find more information about the apiVersion field.
  • The different fields present in the Chart.yaml file has been ordered alphabetically in a homogeneous way for all the Bitnami Helm Charts

Considerations when upgrading to this version

  • If you want to upgrade to this version from a previous one installed with Helm v3, you shouldn’t face any issues
  • If you want to upgrade to this version using Helm v2, this scenario is not supported as this version doesn’t support Helm v2 anymore
  • If you installed the previous version with Helm v2 and wants to upgrade to this version with Helm v3, please refer to the official Helm documentation about migrating from Helm v2 to v3

Useful links

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"}]'