config: adding auto http3 config example

configs/google_com_auto_http3_upstream_proxy.yaml

@@ -0,0 +1,72 @@
+# An example config which accepts HTTP/1 requests over TCP and forwards them to google using HTTP/3
+admin:
+  address:
+    socket_address:
+      protocol: TCP
+      address: 0.0.0.0
+      port_value: 9901
+static_resources:
+  listeners:
+  - name: listener_0
+    address:
+      socket_address:
+        protocol: TCP
+        address: 0.0.0.0
+        port_value: 10000
+    filter_chains:
+    - filters:
+      - name: envoy.filters.network.http_connection_manager
+        typed_config:
+          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+          scheme_header_transformation:
+            scheme_to_overwrite: https
+          stat_prefix: ingress_http
+          route_config:
+            name: local_route
+            virtual_hosts:
+            - name: local_service
+              domains: ["*"]
+              routes:
+              - match:
+                  prefix: "/"
+                route:
+                  host_rewrite_literal: www.google.com
+                  cluster: service_google
+          http_filters:
+          - name: alternate_protocols_cache
+            typed_config:
+              "@type": type.googleapis.com/envoy.extensions.filters.http.alternate_protocols_cache.v3.FilterConfig
+              alternate_protocols_cache_options:
+                name: default_alternate_protocols_cache
+          - name: envoy.filters.http.router
+  clusters:
+  - name: service_google
+    connect_timeout: 30s
+    type: LOGICAL_DNS
+    # Comment out the following line to test on v6 networks
+    dns_lookup_family: V4_ONLY
+    lb_policy: ROUND_ROBIN
+    load_assignment:
+      cluster_name: service_google
+      endpoints:
+      - lb_endpoints:
+        - endpoint:
+            address:
+              socket_address:
+                address: www.google.com
+                port_value: 443
+    typed_extension_protocol_options:
+      envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
+        "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
+        auto_config:
+          http3_protocol_options: {}
+          alternate_protocols_cache_options:
+            name: default_alternate_protocols_cache
+        common_http_protocol_options:
+          idle_timeout: 1s
+    transport_socket:
+      name: envoy.transport_sockets.quic
+      typed_config:
+        "@type": type.googleapis.com/envoy.extensions.transport_sockets.quic.v3.QuicUpstreamTransport
+        upstream_tls_context:
+          sni: www.google.com