# Istio

Istio is a power traffic mesh management tool. It also provides an ingress gateway for the Kubernetes cluster.

## Installation

### Operator Setup

* The following setup can be done from the client machine. This installs Istio Operator, Istio Service Mesh, Istio Ingressgateway components.
* From [kubernetes/istio](https://github.com/OpenG2P/openg2p-deployment/tree/main/kubernetes/istio) directory, run;

  ```bash
  istioctl operator init
  kubectl apply -f istio-operator.yaml
  ```

  * Wait for `istiod` and `ingressgateway` pods to start.
* Or, for Rancher cluster, run:

  ```bash
  kubectl apply -f istio-ef-spdy-upgrade.yaml
  ```

### Namespace Setup

(Skip this section for Rancher cluster)

Set up an Istio gateway on each namespace for a domain. This assumes that the namespace (and relevant Rancher project) are already created (you may use the Rancher console to create a namespace or via command line `kubectl`)

* Edit and run this to define the variables:

  ```
  export NS=dev
  export WILDCARD_HOSTNAME='*.dev.your.org'
  ```
* From [kubernetes/istio](https://github.com/OpenG2P/openg2p-deployment/tree/main/kubernetes/istio) directory, run the following:

  ```bash
  envsubst < istio-gateway.yaml | kubectl apply -f -
  ```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.openg2p.org/1.3/deployment/base-infrastructure/openg2p-cluster/cluster-setup/istio.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.