Kubernetes and Helm

Mammoth ships with a Helm chart stored in the repository:

charts/mammoth

Current Distribution Model

The Helm chart is currently distributed through the Mammoth Git repository.

A dedicated Helm repository is not yet published.

Clone the repository:

git clone https://github.com/kanutocd/mammoth.git
cd mammoth

Render Manifests

helm template mammoth ./charts/mammoth \
  --set image.repository=ghcr.io/kanutocd/mammoth \
  --set image.tag=latest

Install

helm install mammoth ./charts/mammoth \
  --set image.repository=ghcr.io/kanutocd/mammoth \
  --set image.tag=latest

Upgrade

helm upgrade mammoth ./charts/mammoth \
  --set image.repository=ghcr.io/kanutocd/mammoth \
  --set image.tag=latest

Uninstall

helm uninstall mammoth

Required External Resources

The chart deploys Mammoth. It does not create your full CDC environment.

You must provide:

• PostgreSQL reachable from the cluster
• PostgreSQL logical replication settings
• publication
• replication slot or auto_create_slot: true
• Kubernetes Secret for the PostgreSQL password
• webhook destination reachable from the cluster

PostgreSQL Password Secret

Default chart values expect:

postgres:
  existingSecret:
    name: postgres-secrets
    key: password

Create a development secret:

kubectl create secret generic postgres-secrets \
  --from-literal=password=postgres

Image Settings

Default values:

image:
  repository: ghcr.io/kanutocd/mammoth
  tag: "0.1.1"
  pullPolicy: IfNotPresent

Override image settings:

helm upgrade --install mammoth ./charts/mammoth \
  --set image.repository=ghcr.io/kanutocd/mammoth \
  --set image.tag=latest

Kind Local Development

For local Kind testing with a locally built image:

kind load docker-image live_postgres_webhook-mammoth:latest --name mammoth

Install or upgrade with:

helm upgrade --install mammoth ./charts/mammoth \
  --set image.repository=live_postgres_webhook-mammoth \
  --set image.tag=latest \
  --set image.pullPolicy=IfNotPresent

PostgreSQL Service Example

For local Kind testing, you can run PostgreSQL inside Kubernetes and expose it with a Service named postgres-service.

Example Mammoth override:

helm upgrade --install mammoth ./charts/mammoth \
  --set postgres.host=postgres-service \
  --set postgres.port=5432 \
  --set postgres.database=mammoth_demo \
  --set postgres.username=postgres

Webhook URL

The webhook URL must be reachable from inside Kubernetes.

This example will only work if the cluster can reach the public host:

webhook:
  url: https://yourservice.com/webhooks/postgres

For an in-cluster receiver, use a Kubernetes Service DNS name:

webhook:
  url: http://webhook-receiver:9292/webhook

Persistence

The chart mounts a PVC for Mammoth's SQLite database.

SQLite is Mammoth's operational memory for:

• checkpoints
• dead letters
• replay metadata

Default storage:

persistence:
  storage: "1Gi"

Inspect PVCs:

kubectl get pvc

Replica Count and Replication Slots

Run one active Mammoth replica per logical replication slot.

PostgreSQL logical replication slots are consumed by one active subscriber at a time, so the chart uses a single replica by default.

replicaCount: 1

Useful Commands

Inspect deployment status:

kubectl get pods
kubectl get pvc
kubectl logs deploy/mammoth
kubectl describe pod -l app.kubernetes.io/name=mammoth

Inspect Helm values and manifests:

helm get values mammoth --all
helm get manifest mammoth

Restart Mammoth:

kubectl rollout restart deploy/mammoth

Troubleshooting

See:

• docs/troubleshooting.md

Common topics include:

• Helm installation issues
• Kubernetes Secret configuration
• PostgreSQL connectivity
• Publications and replication slots
• Webhook delivery troubleshooting
• SQLite operational state inspection