consul/connect: support for proxy upstreams opaque config (#15761)

This PR adds support for configuring `proxy.upstreams[].config` for
Consul Connect upstreams. This is an opaque config value to Nomad -
the data is passed directly to Consul and is unknown to Nomad.

command/agent/consul/connect.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/hashicorp/consul/api"
 	"github.com/hashicorp/nomad/nomad/structs"
+	"golang.org/x/exp/maps"
 	"golang.org/x/exp/slices"
 )
 
@@ -202,6 +203,7 @@ func connectUpstreams(in []structs.ConsulUpstream) []api.Upstream {
 			Datacenter:           upstream.Datacenter,
 			LocalBindAddress:     upstream.LocalBindAddress,
 			MeshGateway:          connectMeshGateway(upstream.MeshGateway),
+			Config:               maps.Clone(upstream.Config),
 		}
 	}
 	return upstreams

command/agent/consul/connect_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/hashicorp/nomad/helper/pointer"
 	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad/structs"
+	"github.com/shoenig/test/must"
 	"github.com/stretchr/testify/require"
 )
 
@@ -360,11 +361,11 @@ func TestConnect_connectUpstreams(t *testing.T) {
 	ci.Parallel(t)
 
 	t.Run("nil", func(t *testing.T) {
-		require.Nil(t, connectUpstreams(nil))
+		must.Nil(t, connectUpstreams(nil))
 	})
 
 	t.Run("not empty", func(t *testing.T) {
-		require.Equal(t,
+		must.Eq(t,
 			[]api.Upstream{{
 				DestinationName: "foo",
 				LocalBindPort:   8000,
@@ -374,6 +375,7 @@ func TestConnect_connectUpstreams(t *testing.T) {
 				LocalBindPort:        9000,
 				Datacenter:           "dc2",
 				LocalBindAddress:     "127.0.0.2",
+				Config:               map[string]any{"connect_timeout_ms": 5000},
 			}},
 			connectUpstreams([]structs.ConsulUpstream{{
 				DestinationName: "foo",
@@ -384,6 +386,7 @@ func TestConnect_connectUpstreams(t *testing.T) {
 				LocalBindPort:        9000,
 				Datacenter:           "dc2",
 				LocalBindAddress:     "127.0.0.2",
+				Config:               map[string]any{"connect_timeout_ms": 5000},
 			}}),
 		)
 	})

command/agent/job_endpoint.go

@@ -1668,6 +1668,7 @@ func apiUpstreamsToStructs(in []*api.ConsulUpstream) []structs.ConsulUpstream {
 			Datacenter:           upstream.Datacenter,
 			LocalBindAddress:     upstream.LocalBindAddress,
 			MeshGateway:          apiMeshGatewayToStructs(upstream.MeshGateway),
+			Config:               maps.Clone(upstream.Config),
 		}
 	}
 	return upstreams