<!-- 
  -- Note: this file contains a generated diagram. Use `./gradlew :architectureDoc` to generate 
  -->

# Gradle platform architecture

The diagram below shows the main components of the Gradle architecture. See [ADR4](standards/0004-use-a-platform-architecture.md) for more details.

<!-- This diagram is generated. Use `./gradlew :architectureDoc` to update it -->
```mermaid
    graph TD

    subgraph core["core platform"]

    - **Pilot** - Responsible for configuring the proxies at runtime.

    - **Citadel** - Responsible for certificate issuance and rotation.

    - **Galley** - Responsible for validating, ingesting, aggregating, transforming and distributing config within Istio.

- **Operator** - The component provides user friendly options to operate the Istio service mesh.

Any changes to this folder should have a `make copy-templates` applied afterwards.

Warning: unlike the `IstioOperator` profiles, these profiles cannot enable or disable certain components.
As a result, users still need to ensure they install the appropriate charts to use a profile correctly.

Note: there are still some cluster roles that may need to be fixed, most likely cluster permissions
will need to move to the security component.

## Everything is Optional

Each component in the new installer is optional. Users can install the component defined in the new installer,
use the equivalent component in `istio-system`, configured with the official installer, or use a different
version or implementation.

The operator uses the [IstioOperator API](https://github.com/istio/api/blob/master/operator/v1alpha1/operator.proto), which has
three main components:

- [MeshConfig](https://github.com/istio/api/blob/master/mesh/v1alpha1/config.proto) for runtime config consumed directly by Istio
control plane components.
- [Component configuration API](https://github.com/istio/api/blob/00671adacbea20f941cb20cce021bc63cbad1840/operator/v1alpha1/operator.proto#L42-L93), for managing

1. Check k8s pod namespace against exclusion list (plugin config)
    - Config must exclude namespace that Istio control-plane is installed in (TODO: this may change, exclude at pod level is sufficient and we may want Istiod and other istio components to use ambient too)
    - If excluded, ignore the pod and return prevResult
1. Setup redirect rules for the pods:
    - Get the port list from pods definition, as well as annotations.

```bash
helm delete my-release
```

or

```bash
helm uninstall my-release
```

#### Figure 2 - KMS key hierarchy

```
                                                          CMK (master key)

* How to set **validation constraints** as `maximum_length` or `regex`.
* A very powerful and easy to use **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.
* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth.