Kubernetes Helm Chart Structure
===============================

1. Chart scaffold
-----------------

**File:** ``helm-chart/Chart.yaml``
Defines a v2 application chart named ``influxion``, versioned 0.1.0, with ``appVersion: "latest"``.

**File:** ``helm-chart/values.yaml``
Holds all of the top-level values you pass via ``--set ...`` in your PowerShell script (``image.*``, ``vault.*``, ``postgres.*``, ``rabbitmq.*``, ``service.port/type``, ``worker.replicaCount``, etc.).

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2. Helpers
----------

**File:** ``helm-chart/templates/_helpers.tpl``
Defines two simple helpers—``influxion.name`` and ``influxion.fullname``—so that all resources share consistent naming (``<name>-<release>``).

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3. Vault secret
---------------

**File:** ``helm-chart/templates/vault-secret.yaml``
Creates an Opaque Secret from ``.Values.vault.*`` with exactly the four keys your app and worker need:

::

    INFLUXION_VAULT_URL           # from vault.url
    INFLUXION_AZURE_CLIENT_ID     # from vault.clientId
    INFLUXION_AZURE_CLIENT_SECRET # from vault.clientSecret
    INFLUXION_AZURE_TENANT_ID     # from vault.tenantId

This matches your deploy script’s ``--set vault.url... vault.clientId... vault.clientSecret... vault.tenantId...``.

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4. Postgres StatefulSet & Service
---------------------------------

**File:** ``helm-chart/templates/statefulset-postgres.yaml``
**File:** ``helm-chart/templates/service-postgres.yaml``

Spins up a single-replica PostgreSQL StatefulSet (with a PVC sized from ``values.postgres.persistence.size``) and a ClusterIP service on port 5432, using the same credentials as in ``docker-compose.yml``.

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5. RabbitMQ Deployment & Service
--------------------------------

**File:** ``helm-chart/templates/deployment-rabbitmq.yaml``
**File:** ``helm-chart/templates/service-rabbitmq.yaml``

Matches ``docker-compose.yml``’s ``rabbitmq:3-management`` container, exposing AMQP (5672) and management (15672) ports, and passing ``RABBITMQ_DEFAULT_USER`` / ``RABBITMQ_DEFAULT_PASS`` from ``values.rabbitmq.auth``.

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6. Influxion “app” Deployment & Service
---------------------------------------

**File:** ``helm-chart/templates/deployment-app.yaml``
**File:** ``helm-chart/templates/service-app.yaml``

Recreates the FastAPI service:

* Uses ``values.image.app.*``,
* Exposes ``values.service.port``,
* Injects the same ``INFLUXION_DATABASE_URL``, ``INFLUXION_USE_CELERY``, ``INFLUXION_CELERY_*`` settings,
* Mounts the Key-Vault secrets (``INFLUXION_VAULT_URL`` + Azure client/secret/tenant) via the secret created above.

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7. Ingress Configuration
------------------------

**File:** ``helm-chart/templates/ingress-app.yaml``

Optionally creates an Ingress to expose the FastAPI service externally on HTTP port 80 (default LoadBalancer IP), controlled by ``values.ingress.*`` settings:

::

    ingress:
      enabled: false         # toggle Ingress deployment
      className: nginx       # ingress class
      hosts:
        - host: influxion.example.com
      paths:
        - path: /
          pathType: Prefix
      # TLS: secretName for cert-manager; hosts derive from ingress.hosts
      tls:
        - secretName: influxion-tls

The template applies these settings to generate the Ingress resource on Kubernetes.

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8. Influxion “worker” Deployment
--------------------------------

**File:** ``helm-chart/templates/deployment-worker.yaml``

Matches your x-worker-def in Docker Compose:

* Uses ``values.image.worker.*``,
* Always sets ``INFLUXION_USE_CELERY=1``,
* Points to the same database, broker, vault secret,
* Replica count from ``values.worker.replicaCount``.

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How it dovetails with deploy_to_aks.ps1
---------------------------------------

Your PowerShell command does:

::

    helm upgrade --install influxion ./helm-chart ... `
      --set image.app.repository=... `
      --set image.app.tag=... `
      --set image.worker.repository=... `
      --set image.worker.tag=... `
      --set vault.url="$VaultUrl" `
      --set vault.clientId="$VaultClientId" `
      --set vault.clientSecret="$VaultClientSecret" `
      --set vault.tenantId="$VaultTenantId" `
      --set ingress.enabled=true `
      --set ingress.className="$IngressClass" `
      --set ingress.hosts[0].host="$IngressHost"

.. note::
   If you override only the host (via ``--set ingress.hosts[0].host``), the chart will automatically
   configure a single path ``/`` with pathType ``Prefix``, so you don't need to explicitly set
   ``ingress.hosts[0].paths``.

The chart’s ``values.yaml`` and templates consume exactly those four ``vault.*`` keys, plus the image settings, so everything will wire up smoothly on AKS.