PostHog chart configuration

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This document outlines the most important configuration options available in the chart.

Dependencies

By default, the chart installs the following dependencies:

There is optional support for the following additional dependencies:

Chart configuration

All PostHog Helm chart configuration options can be found in the ALL_VALUES.md generated from the values.yaml file.

Dependent charts can also have values overwritten. See Chart.yaml for more info regarding the source shard and the namespace that can be used for the override.

Scaling up

The default configuration is geared towards minimizing costs. Here are example extra values overrides to use for scaling up:

Custom overrides for < 1M events/month
# Note: those overrides are experimental as each installation and workload is unique
# Use larger storage for stateful services
clickhouse:
persistence:
size: 60Gi
postgresql:
persistence:
size: 30Gi
kafka:
persistence:
size: 60Gi
logRetentionBytes: _45_000_000_000
# Add additional replicas for the stateless services
events:
replicacount: 2
pgbouncer:
replicacount: 2
plugins:
replicacount: 2
web:
replicacount: 2
worker:
replicacount: 2
Custom overrides for > 1M events/month
# Note: those overrides are experimental as each installation and workload is unique
# Use larger storage for stateful services
clickhouse:
persistence:
size: 200Gi
postgresql:
persistence:
size: 100Gi
kafka:
persistence:
size: 200Gi
logRetentionBytes: _150_000_000_000
# Enable horizontal pod autoscaling for stateless services
events:
hpa:
enabled: true
pgbouncer:
hpa:
enabled: true
plugins:
hpa:
enabled: true
web:
hpa:
enabled: true
worker:
hpa:
enabled: true

Using dedicated nodes for services

For the stateful services (ClickHouse, Kafka, Redis, PostgreSQL, Zookeeper), we suggest you to run them on nodes with dedicated CPU resources and fast drives (SSD/NVMe).

In order to do so, after having labeled your Kubernetes nodes, you can assign pods to them using the following overrides:

  • ClickHouse: clickhouse.nodeSelector
  • Kafka: kafka.nodeSelector
  • Redis: redis.master.nodeSelector
  • PostgreSQL: postgresql.master.nodeSelector
  • Zookeeper: zookeeper.nodeSelector

Example:

clickhouse.nodeSelector:
diskType: ssd
nodeType: fast

For more fine grained options, affinity and tolerations overrides are also available for the majority of the stateful components. See the official Kubernetes documentation for more info.

Email (SMTP service)

For PostHog to be able to send emails we need a working SMTP service available. You can configure PostHog to use the service by editing the email section of your values.yaml file. Example:

email:
host: <SMTP service host>
port: <SMTP service port>

If your SMTP services requires authentication (recommended) you can either:

  • directly provide the SMTP login in the values.yaml by simply setting email.user and email.password
Example
email:
host: <SMTP service host>
port: <SMTP service port>
user: <SMTP service user>
password: <SMTP service password>
  • provide the password via a Kubernetes secret, by configuring email.existingSecret and email.existingSecretKey accordingly
Example
  1. create the secret by running: kubectl -n posthog create secret generic "smtp-password" --from-literal="password=<YOUR_PASSWORD>"

  2. configure your values.yaml to reference the secret:

    email:
    host: <SMTP service host>
    port: <SMTP service port>
    user: <SMTP service user>
    existingSecret: "smtp-password"
    existingSecretKey: "password"

ClickHouse

ClickHouse is the datastore system that does the bulk of heavy lifting with regards to storing and analyzing the analytics data.

By default, ClickHouse is installed as a part of the chart, powered by clickhouse-operator. You can also use a ClickHouse managed service like Altinity (see here for more info).

Securing ClickHouse

By default, the PostHog Helm Chart will provision a ClickHouse cluster using a default username and password. Please provide a unique login by overriding the clickhouse.user and clickhouse.password values.

By default, the PostHog Helm Chart uses a ClusterIP to expose the service internally to the rest of the PostHog application. This should prevent any external access.

If however you decide you want to access the ClickHouse cluster external to the Kubernetes cluster and need to expose it e.g. to the internet, keep in mind the following:

  1. the Helm Chart does not configure TLS for ClickHouse, thus we would recommend that you ensure that you configure TLS e.g. within a load balancer in front of the cluster.

  2. if exposing via a LoadBalancer or NodePort service type via clickhouse.serviceType, these will both expose a port on your Kubernetes nodes. We recommend you ensure that your Kubernetes worker nodes are within a private network or in a public network with firewall rules in place.

  3. if exposing via a LoadBalancer service type, restrict the ingress network access to the load balancer

  4. to restrict access to the ClickHouse cluster, ClickHouse offers settings for restricting the IPs/hosts that can access the cluster. See the user_name/networks setting for details. We expose this setting via the Helm Chart as clickhouse.allowedNetworkIps

Use an external service

To use an external ClickHouse service, please set clickhouse.enabled to false and then configure the externalClickhouse values.

Find out how to deploy PostHog using Altinity Cloud in our deployment configuration docs.

Custom settings

It's possible to pass custom settings to ClickHouse. This might be needed to e.g. set query time limits or increase max memory usable by clickhouse.

To do so, you can override the clickhouse.profiles values as below. The default profile is used by PostHog for all queries.

clickhouse:
profiles:
default/max_execution_time: "180"
default/max_memory_usage: "40000000000"

Read more about ClickHouse settings here.

See ALL_VALUES.md for full configuration options.

MinIO

By default, MinIO is not installed as part of the chart. If you want to enable it, please set minio.enabled to true.

MinIO provide a scalable, S3 compatible object storage system. You can customize all its settings by overriding values.yaml variables in the minio namespace.

Note: please override the default user authentication by either passing auth.rootUser and auth.rootPassword or auth.existingSecret.

Use an external service

To use an external S3 like/compatible object storage, please set minio.enabled to false and then configure the externalObjectStorage values.

See ALL_VALUES.md and the MinIO chart for full configuration options.

PostgreSQL

While ClickHouse powers the bulk of the analytics if you deploy PostHog using this chart, Postgres is still needed as a data store for PostHog to work.

PostgreSQL is installed by default as part of the chart. You can customize all its settings by overriding values.yaml variables in the postgresql namespace.

Note: to avoid issues when upgrading this chart, provide postgresql.postgresqlPassword for subsequent upgrades. This is due to an issue in the PostgreSQL upstream chart where password will be overwritten with randomly generated passwords otherwise. See PostgreSQL#upgrade for more details.

Use an external service

To use an external PostgreSQL service, please set postgresql.enabled to false and then configure the externalPostgresql values.

See ALL_VALUES.md and the PostgreSQL chart for full configuration options.

PgBouncer

PgBouncer is a lightweight connection pooler for PostgreSQL and it is installed by default as part of the chart. It is currently required in order for the installation to work (see here for more info).

If you've configured your PostgreSQL instance to require the use of TLS, you'll need to pass an additional env variables to the PgBouncer deployment (see the official documentation for more info). Example:

pgbouncer:
env:
- name: SERVER_TLS_SSLMODE
value: "your_value"

See ALL_VALUES.md for full configuration options.

Redis

Redis is installed by default as part of the chart. You can customize all its settings by overriding values.yaml variables in the redis namespace.

Use an external service

To use an external Redis service, please set redis.enabled to false and then configure the externalRedis values.

Example
redis:
enabled: false
externalRedis:
host: "posthog.cache.us-east-1.amazonaws.com"
port: 6379

Credentials

By default, Redis doesn't use any password for authentication. If you want to configure it to use a password (recommended) see the options below.

Internal Redis
  • set redis.auth.enabled to true

  • to directly provide the password value in the values.yaml simply set it in redis.auth.password

  • if you want to provide the password via a Kubernetes secret, please configure redis.auth.existingSecret and redis.auth.existingSecretPasswordKey accordingly:

    Example

    1. create the secret by running: kubectl -n posthog create secret generic "redis-existing-secret" --from-literal="redis-password=<YOUR_PASSWORD>"

    2. configure your values.yaml to reference the secret:

      redis:
      enabled: true
      auth:
      enabled: true
      existingSecret: "redis-existing-secret"
      existingSecretPasswordKey: "redis-password"
External Redis
  • to directly provide the password value in the values.yaml simply set it in externalRedis.password

  • if you want to provide a password via an existing secret, please configure externalRedis.existingSecret and externalRedis.existingSecretPasswordKey accordingly:

    Example

    1. create the secret by running: kubectl -n posthog create secret generic "redis-existing-secret" --from-literal="redis-password=<YOUR_PASSWORD>"

    2. configure your values.yaml to reference the secret:

      redis:
      enable: false
      externalRedis:
      host: "<YOUR_REDIS_HOST>"
      port: <YOUR_REDIS_PORT>
      existingSecret: "redis-existing-secret"
      existingSecretPasswordKey: "redis-password"

See ALL_VALUES.md and the Redis chart for full configuration options.

Kafka

Kakfa is installed by default as part of the chart. You can customize all its settings by overriding values.yaml variables in the kafka namespace.

Use an external service

To use an external Kafka service, please set kafka.enabled to false and then configure the externalKafka values.

Example
kafka:
enabled: false
externalKafka:
brokers:
- "broker-1.posthog.kafka.us-east-1.amazonaws.com:9094"
- "broker-2.posthog.kafka.us-east-1.amazonaws.com:9094"
- "broker-3.posthog.kafka.us-east-1.amazonaws.com:9094"

See ALL_VALUES.md and the Kafka chart for full configuration options.

Ingress

This chart provides support for the Ingress resource. If you have an available Ingress Controller such as Nginx or Traefik you maybe want to set ingress.nginx.enabled to true or ingress.type and choose an ingress.hostname for the URL. Then, you should be able to access the installation using that address.

Grafana

By default, grafana is not installed as part of the chart. If you want to enable it, please set grafana.enabled to true.

The default settings provide a vanilla installation with an auto generated login. The username is admin and the auto-generated password can be fetched by running:

kubectl -n posthog get secret posthog-grafana -o jsonpath="{.data.admin-password}" | base64 --decode

To configure the stack (like expose the service via an ingress resource, manage users, ...) please look at the inputs provided by the upstream chart.

See ALL_VALUES.md and the grafana chart for full configuration options.

Loki

By default, loki is not installed as part of the chart. If you want to enable it, please set loki.enabled to true.

To configure the stack (like expose the service via an ingress resource, ...) please look at the inputs provided by the upstream chart.

See ALL_VALUES.md and the loki chart for full configuration options.

Promtail

By default, promtail is not installed as part of the chart. If you want to enable it, please set promtail.enabled to true.

To configure the stack (like expose the service via an ingress resource, ...) please look at the inputs provided by the upstream chart.

See ALL_VALUES.md and the promtail chart for full configuration options.

Prometheus

This chart supports alerting. Set prometheus.enabled to true and set prometheus.alertmanagerFiles to the right configuration.

Read more at Prometheus chart and Prometheus configuration

Example configuration (PagerDuty)

prometheus:
enabled: true
alertmanagerFiles:
alertmanager.yml:
receivers:
- name: default-receiver
pagerduty_configs:
- routing_key: YOUR_ROUTING_KEY
description: "{{ range .Alerts }}{{ .Annotations.summary }}\n{{ end }}"
route:
group_by: [alertname]
receiver: default-receiver

Getting access to the Prometheus UI

This might be useful when checking out metrics. Figure out your prometheus-server pod name via kubectl get pods --namespace NS and run: kubectl --namespace NS port-forward posthog-prometheus-server-XXX 9090.

After this, you should be able to access Prometheus server on localhost.

Statsd / prometheus-statsd-exporter

By default, StatsD is not installed as part of the chart. If you want to enable it, please set prometheus-statsd-exporter.enabled to true.

Use an external service

To use an external StatsD service, please set prometheus-statsd-exporter.enabled to false and then configure the externalStatsd values.

See ALL_VALUES.md and prometheus-statsd-exporter chart for full configuration options.

prometheus-kafka-exporter

By default, prometheus-kafka-exporter is not installed as part of the chart. If you want to enable it, please set prometheus-kafka-exporter.enabled to true. If you are using an external Kafka, please configure prometheus-kafka-exporter.kafkaServer accordingly.

See ALL_VALUES.md and prometheus-kafka-exporter chart for full configuration options.

prometheus-postgres-exporter

By default, prometheus-postgres-exporter is not installed as part of the chart. If you want to enable it, please set prometheus-postgres-exporter.enabled to true. If you are using an external Kafka, please configure prometheus-postgres-exporter.config.datasource accordingly.

See ALL_VALUES.md and prometheus-postgres-exporter chart for full configuration options.

prometheus-redis-exporter

By default, prometheus-redis-exporter is not installed as part of the chart. If you want to enable it, please set prometheus-redis-exporter.enabled to true. If you are using an external Redis, please configure prometheus-redis-exporter.redisAddress accordingly.

See ALL_VALUES.md and prometheus-redis-exporter chart for full configuration options.

Questions?