charts/postgresql-walg

PostgreSQL

PostgreSQL is a powerful, open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness.

TL;DR;

$ helm install stable/postgresql

Introduction

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

Prerequisites

• Kubernetes 1.4+ with Beta APIs enabled
• PV provisioner support in the underlying infrastructure (Only when persisting data)

Installing the Chart

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

$ helm install --name my-release stable/postgresql

The command deploys PostgreSQL on the Kubernetes cluster in the default configuration. The configuration 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.

Configuration

The following table lists the configurable parameters of the PostgreSQL chart and their default values.

Parameter	Description	Default
image	postgres image repository	postgres
imageTag	postgres image tag	9.6.2
imagePullPolicy	Image pull policy	Always if imageTag is latest, else IfNotPresent
imagePullSecrets	Image pull secrets	nil
postgresUser	Username of new user to create.	postgres
postgresPassword	Password for the new user.	random 10 characters
usePasswordFile	Inject the password via file instead of env var	false
postgresDatabase	Name for new database to create.	postgres
postgresInitdbArgs	Initdb Arguments	nil
schedulerName	Name of an alternate scheduler	nil
existingSecret	Use Existing secret for Admin password	nil
postgresConfig	Runtime Config Parameters	nil
persistence.enabled	Use a PVC to persist data	true
persistence.existingClaim	Provide an existing PersistentVolumeClaim	nil
persistence.storageClass	Storage class of backing PVC	nil (uses alpha storage class annotation)
persistence.accessMode	Use volume as ReadOnly or ReadWrite	ReadWriteOnce
persistence.annotations	Persistent Volume annotations	{}
persistence.size	Size of data volume	8Gi
persistence.subPath	Subdirectory of the volume to mount at	postgresql-db
persistence.mountPath	Mount path of data volume	/var/lib/postgresql/data/pgdata
resources	CPU/Memory resource requests/limits	Memory: 256Mi, CPU: 100m
metrics.enabled	Start a side-car prometheus exporter	false
metrics.image	Exporter image	wrouesnel/postgres_exporter
metrics.imageTag	Exporter image	v0.1.1
metrics.imagePullPolicy	Exporter image pull policy	IfNotPresent
metrics.resources	Exporter resource requests/limit	Memory: 256Mi, CPU: 100m
metrics.customMetrics	Additional custom metrics	nil
service.externalIPs	External IPs to listen on	[]
service.port	TCP port	5432
service.type	k8s service type exposing ports, e.g. NodePort	ClusterIP
service.nodePort	NodePort value if service.type is NodePort	nil
networkPolicy.enabled	Enable NetworkPolicy	false
networkPolicy.allowExternal	Don't require client label for connections	true
nodeSelector	Node labels for pod assignment	{}
affinity	Affinity settings for pod assignment	{}
tolerations	Toleration labels for pod assignment	[]
probes.liveness.initialDelay	Liveness probe initial delay	60
probes.liveness.timeoutSeconds	Liveness probe timeout seconds	5
probes.liveness.failureThreshold	Liveness probe failure threshold	6
probes.readiness.initialDelay	Readiness probe initial delay	5
probes.readiness.timeoutSeconds	Readiness probe timeout seconds	3
probes.readiness.failureThreshold	Readiness probe failure threshold	5
podAnnotations	Annotations for the postgresql pod	{}
deploymentAnnotations	Annotations for the postgresql deployment	{}

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

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

$ helm install --name my-release \
  --set postgresUser=my-user,postgresPassword=secretpassword,postgresDatabase=my-database \
    stable/postgresql

The above command creates a PostgreSQL user named my-user with password secretpassword. Additionally it creates a database named my-database.

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

$ helm install --name my-release -f values.yaml stable/postgresql

Tip: You can use the default values.yaml

Persistence

The postgres image stores the PostgreSQL data and configurations at the /var/lib/postgresql/data/pgdata path of the container.

The chart mounts a Persistent Volume at this location. The volume is created using dynamic volume provisioning. If the PersistentVolumeClaim should not be managed by the chart, define persistence.existingClaim.

Note: When using persistence ensure that you either provide a postgresPassword or use existingSecret, otherwise helm update will generate a new random password which is ignored by postgres. That will cause confusing behaviour especially if services depend on the secret

Existing PersistentVolumeClaims

1. Create the PersistentVolume
2. Create the PersistentVolumeClaim
3. Install the chart

$ helm install --set persistence.existingClaim=PVC_NAME postgresql

The volume defaults to mount at a subdirectory of the volume instead of the volume root to avoid the volume's hidden directories from interfering with initdb. If you are upgrading this chart from before version 0.4.0, set persistence.subPath to "".

Metrics

The chart optionally can start a metrics exporter for prometheus. The metrics endpoint (port 9187) is not exposed and it is expected that the metrics are collected from inside the k8s cluster using something similar as the described in the example Prometheus scrape configuration.

The exporter allows to create custom metrics from additional SQL queries. See the Chart's values.yaml for an example and consult the exporters documentation for more details.

NetworkPolicy

To enable network policy for PostgreSQL, install a networking plugin that implements the Kubernetes NetworkPolicy spec, and set networkPolicy.enabled to true.

For Kubernetes v1.5 & v1.6, you must also turn on NetworkPolicy by setting the DefaultDeny namespace annotation. Note: this will enforce policy for all pods in the namespace:

kubectl annotate namespace default "net.beta.kubernetes.io/network-policy={\"ingress\":{\"isolation\":\"DefaultDeny\"}}"

With NetworkPolicy enabled, traffic will be limited to just port 5432.

For more precise policy, set networkPolicy.allowExternal=false. This will only allow pods with the generated client label to connect to PostgreSQL. This label will be displayed in the output of a successful install.