»Service Mesh Proxy Overview
Proxies enable unmodified applications to connect to other services in the service mesh. A per-service proxy sidecar transparently handles inbound and outbound service connections, automatically wrapping and verifying TLS connections. Consul ships with a built-in L4 proxy and has first class support for Envoy. You can plug other proxies into your environment as well. This section describes how to configure Envoy or the built-in proxy using Connect, and how to integrate the proxy of your choice.
To ensure that services only allow external connections established through the service mesh protocol, you should configure all services to only accept connections on a loopback address.
Dynamic upstreams require native integration
Service mesh proxies do not support dynamic upstreams.
If an application requires dynamic dependencies that are only available at runtime, you must natively integrate the application with Consul service mesh. After natively integrating, the HTTP API or DNS interface can be used.