Mongodb Helm Chart Deploy

Prerequisites

• Kubernetes 1.21+
• Helm 2.11+ or Helm 3
• PV provisioner support in the underlying infrastructure
• ReadWriteMany volumes for deployment scaling

Installing the Chart

Tip: You can use the default values.yaml

$ kubectl create ns mongodb

$ helm install my-release . -f values.yaml -n mongodb

The command deploys MongoDB on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete -n mongodb my-release 

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

Parameters

The following table lists the configurable parameters of the MongoDB 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	MongoDB image registry	docker.io
image.repository	MongoDB Image name	bitnami/mongodb
image.tag	MongoDB Image tag	{TAG_NAME}
image.pullPolicy	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
nameOverride	String to partially override mongodb.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override mongodb.fullname template with a string	nil
volumePermissions.enabled	Enable init container that changes volume permissions in the data directory (for cases where the default k8s runAsUser and fsUser values do not work)	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	nil
clusterDomain	Default Kubernetes cluster domain	cluster.local
usePassword	Enable password authentication	true
existingSecret	Existing secret with MongoDB credentials	nil
mongodbRootPassword	MongoDB admin password	random alphanumeric string (10)
mongodbUsername	MongoDB custom user (mandatory if mongodbDatabase is set)	nil
mongodbPassword	MongoDB custom user password	random alphanumeric string (10)
mongodbDatabase	Database to create	nil
mongodbEnableIPv6	Switch to enable/disable IPv6 on MongoDB	false
mongodbDirectoryPerDB	Switch to enable/disable DirectoryPerDB on MongoDB	false
mongodbSystemLogVerbosity	MongoDB system log verbosity level	0
mongodbDisableSystemLog	Whether to disable MongoDB system log or not	false
mongodbExtraFlags	MongoDB additional command line flags	[]
service.name	Kubernetes service name	nil
service.annotations	Kubernetes service annotations, evaluated as a template	{}
service.type	Kubernetes Service type	ClusterIP
service.clusterIP	Static clusterIP or None for headless services	nil
service.port	MongoDB service port	27017
service.nodePort	Port to bind to for NodePort service type	nil
service.loadBalancerIP	Static IP Address to use for LoadBalancer service type	nil
service.externalIPs	External IP list to use with ClusterIP service type	[]
service.loadBalancerSourceRanges	List of IP ranges allowed access to load balancer (if supported)	[] (does not add IP range restrictions to the service)
replicaSet.enabled	Switch to enable/disable replica set configuration	false
replicaSet.name	Name of the replica set	rs0
replicaSet.useHostnames	Enable DNS hostnames in the replica set config	true
replicaSet.key	Key used for authentication in the replica set	random alphanumeric string (10)
replicaSet.replicas.secondary	Number of secondary nodes in the replica set	1
replicaSet.replicas.arbiter	Number of arbiter nodes in the replica set	1
replicaSet.pdb.enabled	Switch to enable/disable Pod Disruption Budget	true
replicaSet.pdb.minAvailable.secondary	PDB (min available) for the MongoDB Secondary nodes	1
replicaSet.pdb.minAvailable.arbiter	PDB (min available) for the MongoDB Arbiter nodes	1
replicaSet.pdb.maxUnavailable.secondary	PDB (max unavailable) for the MongoDB Secondary nodes	nil
replicaSet.pdb.maxUnavailable.arbiter	PDB (max unavailable) for the MongoDB Arbiter nodes	nil
annotations	Annotations to be added to the deployment or statefulsets	{}
labels	Additional labels for the deployment or statefulsets	{}
podAnnotations	Annotations to be added to pods	{}
podLabels	Additional labels for the pod(s).	{}
resources	Pod resources	{}
resourcesArbiter	Pod resources for arbiter when replica set is enabled	{}
priorityClassName	Pod priority class name	``
extraEnvVars	Array containing extra env vars to be added to all pods in the cluster (evaluated as a template)	nil
nodeSelector	Node labels for pod assignment	{}
affinity	Affinity for pod assignment	{}
affinityArbiter	Affinity for arbiter pod assignment	{}
tolerations	Toleration labels for pod assignment	{}
updateStrategy	Statefulsets update strategy policy	RollingUpdate
securityContext.enabled	Enable security context	true
securityContext.fsGroup	Group ID for the container	1001
securityContext.runAsUser	User ID for the container	1001
schedulerName	Name of the k8s scheduler (other than default)	nil
sidecars	Add additional containers to pod	[]
extraVolumes	Add additional volumes to deployment	[]
extraVolumeMounts	Add additional volumes mounts to pod	[]
sidecarsArbiter	Add additional containers to arbiter pod	[]
extraVolumesArbiter	Add additional volumes to arbiter deployment	[]
extraVolumeMountsArbiter	Add additional volumes mounts to arbiter pod	[]
persistence.enabled	Use a PVC to persist data	true
persistence.mountPath	Path to mount the volume at	/bitnami/mongodb
persistence.subPath	Subdirectory of the volume to mount at	""
persistence.storageClass	Storage class of backing PVC	nil (uses alpha storage class annotation)
persistence.accessModes	Use volume as ReadOnly or ReadWrite	[ReadWriteOnce]
persistence.size	Size of data volume	8Gi
persistence.annotations	Persistent Volume annotations	{}
persistence.existingClaim	Name of an existing PVC to use (avoids creating one if this is given)	nil
useStatefulSet	Set to true to use StatefulSet instead of Deployment even when replicaSet.enalbed=false	nil
extraInitContainers	Additional init containers as a string to be passed to the tpl function	{}
livenessProbe.enabled	Enable/disable the Liveness probe	true
livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	30
livenessProbe.periodSeconds	How often to perform the probe	10
livenessProbe.timeoutSeconds	When the probe times out	5
livenessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
livenessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
readinessProbe.enabled	Enable/disable the Readiness probe	true
readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	5
readinessProbe.periodSeconds	How often to perform the probe	10
readinessProbe.timeoutSeconds	When the probe times out	5
readinessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
readinessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
initConfigMap.name	Custom config map with init scripts	nil
configmap	MongoDB configuration file to be used	nil
ingress.enabled	Enable ingress controller resource	false
ingress.certManager	Add annotations for cert-manager	false
ingress.annotations	Ingress annotations	[]
ingress.hosts[0].name	Hostname to your MongoDB installation	mongodb.local
ingress.hosts[0].path	Path within the url structure	/
ingress.tls[0].hosts[0]	TLS hosts	mongodb.local
ingress.tls[0].secretName	TLS Secret (certificates)	mongodb.local-tls
ingress.secrets[0].name	TLS Secret Name	nil
ingress.secrets[0].certificate	TLS Secret Certificate	nil
ingress.secrets[0].key	TLS Secret Key	nil
metrics.enabled	Start a side-car prometheus exporter	false
metrics.image.registry	MongoDB exporter image registry	docker.io
metrics.image.repository	MongoDB exporter image name	bitnami/mongodb-exporter
metrics.image.tag	MongoDB exporter image tag	{TAG_NAME}
metrics.image.pullPolicy	Image pull policy	Always
metrics.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
metrics.podAnnotations.prometheus.io/scrape	Additional annotations for Metrics exporter pod	true
metrics.podAnnotations.prometheus.io/port	Additional annotations for Metrics exporter pod	"9216"
metrics.extraArgs	String with extra arguments for the MongoDB Exporter	``
metrics.resources	Exporter resource requests/limit	{}
metrics.serviceMonitor.enabled	Create ServiceMonitor Resource for scraping metrics using PrometheusOperator	false
metrics.serviceMonitor.namespace	Optional namespace which Prometheus is running in	nil
metrics.serviceMonitor.additionalLabels	Used to pass Labels that are required by the Installed Prometheus Operator	{}
metrics.serviceMonitor.relabellings	Specify Metric Relabellings to add to the scrape endpoint	nil
metrics.serviceMonitor.alerting.rules	Define individual alerting rules as required	{}
metrics.serviceMonitor.alerting.additionalLabels	Used to pass Labels that are required by the Installed Prometheus Operator	{}
metrics.livenessProbe.enabled	Enable/disable the Liveness Check of Prometheus metrics exporter	false
metrics.livenessProbe.initialDelaySeconds	Initial Delay for Liveness Check of Prometheus metrics exporter	15
metrics.livenessProbe.periodSeconds	How often to perform Liveness Check of Prometheus metrics exporter	5
metrics.livenessProbe.timeoutSeconds	Timeout for Liveness Check of Prometheus metrics exporter	5
metrics.livenessProbe.failureThreshold	Failure Threshold for Liveness Check of Prometheus metrics exporter	3
metrics.livenessProbe.successThreshold	Success Threshold for Liveness Check of Prometheus metrics exporter	1
metrics.readinessProbe.enabled	Enable/disable the Readiness Check of Prometheus metrics exporter	false
metrics.readinessProbe.initialDelaySeconds	Initial Delay for Readiness Check of Prometheus metrics exporter	5
metrics.readinessProbe.periodSeconds	How often to perform Readiness Check of Prometheus metrics exporter	5
metrics.readinessProbe.timeoutSeconds	Timeout for Readiness Check of Prometheus metrics exporter	1
metrics.readinessProbe.failureThreshold	Failure Threshold for Readiness Check of Prometheus metrics exporter	3
metrics.readinessProbe.successThreshold	Success Threshold for Readiness Check of Prometheus metrics exporter	1

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

$ helm install my-release . -f values.yaml \
  --set mongodbRootPassword=secretpassword,mongodbUsername=my-user,mongodbPassword=my-password,mongodbDatabase=my-database \
    stable/mongodb

The above command sets the MongoDB root account password to secretpassword. Additionally, it creates a standard database user named my-user, with the password my-password, who has access to a database named my-database.

Configuration and installation details

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.

Production configuration and horizontal scaling

This chart includes a values-production.yaml file where you can find some parameters oriented to production configuration in comparison to the regular values.yaml. You can use this file instead of the default one.

• Switch to enable/disable replica set configuration:

- replicaSet.enabled: false
+ replicaSet.enabled: true

• Start a side-car prometheus exporter:

- metrics.enabled: false
+ metrics.enabled: true

• Enable/disable the Liveness Check of Prometheus metrics exporter:

- metrics.livenessProbe.enabled: false
+ metrics.livenessProbe.enabled: true

• Enable/disable the Readiness Check of Prometheus metrics exporter:

- metrics.readinessProbe.enabled: false
+ metrics.readinessProbe.enabled: true

To horizontally scale this chart, you can use the --replicas flag to modify the number of secondary nodes in your MongoDB replica set.

Replication

You can start the MongoDB chart in replica set mode with the following parameter: replicaSet.enabled=true

Some characteristics of this chart are:

• Each of the participants in the replication has a fixed stateful set so you always know where to find the primary, secondary or arbiter nodes.
• The number of secondary and arbiter nodes can be scaled out independently.
• Easy to move an application from using a standalone MongoDB server to use a replica set.

Persistence

The chart mounts a Persistent Volume at this location. The volume is created using dynamic volume provisioning.

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.

Upgrading

To 7.0.0

From this version, the way of setting the ingress rules has changed. Instead of using ingress.paths and ingress.hosts as separate objects, you should now define the rules as objects inside the ingress.hosts value, for example:

ingress:
  hosts:
  - name: mongodb.local
    path: /

To 6.0.0

From this version, mongodbEnableIPv6 is set to false by default in order to work properly in most k8s clusters, if you want to use IPv6 support, you need to set this variable to true by adding --set mongodbEnableIPv6=true to your helm command.

To 5.0.0

When enabling replicaset configuration, backwards compatibility is not guaranteed unless you modify the labels used on the chart's statefulsets. Use the workaround below to upgrade from versions previous to 5.0.0. The following example assumes that the release name is my-release:

$ kubectl delete statefulset my-release-mongodb-arbiter my-release-mongodb-primary my-release-mongodb-secondary --cascade=false

Configure Ingress

MongoDB can exposed externally using an Ingress controller. To do so, it's necessary to:

• Install the MongoDB chart setting the parameter ingress.enabled=true.
• Create a ConfigMap to map the external port to use and the internal service/port where to redirect the requests (see https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/exposing-tcp-udp-services.md for more information).

For instance, if you installed the MongoDB chart in the default namespace, you can install the stable/nginx-ingress chart setting the "tcp" parameter in the values.yaml used to install the chart as shown below:

...

tcp:
  27017: "default/mongodb:27017"