> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Network Automation

> Learn to use Consul for resilient service traffic management, including routing, traffic splitting, and layer 7 visibility with Envoy.

Leverage Consul’s network automation to deliver resilient, observability-driven service traffic management. You’ll learn how to route requests to healthy endpoints, split traffic between service versions, and gain deep layer 7 visibility with Envoy.

## Dynamic Load Balancing & Traffic Shaping

Consul automatically routes traffic only to registered, healthy service instances. You can define advanced traffic-shaping policies—similar to a load balancer—to split and steer requests:

* **Health-aware routing**: Requests go only to passing checks.
* **Weighted splits**: Distribute traffic (e.g., 80/20) across service subsets.
* **Path-based routing**: Send specific URLs or HTTP methods to designated backends.
* **Failover & multi-cloud**: When an availability zone or cloud provider fails, traffic shifts seamlessly to healthy regions or on-premises datacenters.

<Callout icon="lightbulb" color="#1CB2FE">
  Consul integrates natively with Envoy for L7 control, and you can extend to F5, NGINX, or HAProxy using built-in connectors.
</Callout>

### Integration Partners

| Proxy / Load Balancer | Use Case                       | Learn More                                |
| --------------------- | ------------------------------ | ----------------------------------------- |
| Envoy                 | Full L7 policy & observability | [Envoy Proxy](https://www.envoyproxy.io/) |
| NGINX                 | HTTP/S traffic management      | [NGINX Docs](https://nginx.org/en/docs/)  |
| HAProxy               | High-performance L4/L7 routing | [HAProxy](https://www.haproxy.org/)       |
| F5                    | Enterprise hardware appliances | [F5 Networks](https://www.f5.com/)        |

## Service Splitting Example

1. **Initial state**: All traffic routes to `v1`.
   ```text theme={null}
   User → Consul → web-app v1
   ```
2. **Canary upgrade**: Deploy `v2` and validate.
3. **Traffic shift**: Apply a `service-splitter` policy.

```hcl theme={null}
Kind  = "service-splitter"
Name  = "web-app"
Splits = [
  {
    ServiceSubset = "v2"
    Weight        = 100
  },
  {
    ServiceSubset = "v1"
    Weight        = 0
  },
]
```

<Callout icon="triangle-alert" color="#FF6B6B">
  Ensure both versions pass health checks before shifting traffic. A misconfigured subset with `Weight > 0` and failing health checks will not receive traffic.
</Callout>

## Layer 7 Visibility & Metrics

By pairing Consul’s network automation with Envoy’s built-in metrics, you gain real-time L7 insights:

* Connection counts
* Request latencies and timeouts
* Circuit breaker states

You can export these statistics via StatsD, DogStatsD, or Prometheus and visualize them in Grafana:

<Frame>
  ![The image illustrates network automation, highlighting increased Layer 7 visibility between services and the ability to view metrics like connections and timeouts. It shows a flow from Envoy to Grafana using StatsD, DogStatsD, and Prometheus.](https://kodekloud.com/kk-media/image/upload/v1752877845/notes-assets/images/HashiCorp-Certified-Consul-Associate-Certification-Network-Automation/network-automation-layer7-visibility-diagram.jpg)
</Frame>

## Further Reading

* [Consul Network Automation](https://www.consul.io/docs/network-automation)
* [Consul Service-Splitter](https://www.consul.io/docs/configuration/service-splitter)
* [Grafana Dashboards for Envoy](https://grafana.com/grafana/dashboards/)
* [Prometheus Metrics](https://prometheus.io/docs/concepts/data_model/)

## Links and References

* [Envoy Proxy](https://www.envoyproxy.io/)
* [NGINX Documentation](https://nginx.org/en/docs/)
* [HAProxy Official Site](https://www.haproxy.org/)
* [F5 Networks](https://www.f5.com/)
* [StatsD vs DogStatsD](https://docs.datadoghq.com/developers/dogstatsd/)

<CardGroup>
  <Card title="Watch Video" icon="video" cta="Learn more" href="https://learn.kodekloud.com/user/courses/hashicorp-certified-consul-associate-certification/module/bb95f43b-3acb-4ce2-88ae-0c79beb3e569/lesson/d5757ba4-33f1-44e1-9f17-8ba48fc9788b" />
</CardGroup>