chore: adds test for crosscontroller info.

apiserver/facades/controller/crosscontroller/crosscontroller_test.go

@@ -11,6 +11,8 @@ import (
 	gc "gopkg.in/check.v1"
 
 	"github.com/juju/juju/apiserver/common"
+	"github.com/juju/juju/controller"
+	"github.com/juju/juju/core/network"
 	"github.com/juju/juju/rpc/params"
 	"github.com/juju/juju/state"
 )
@@ -112,3 +114,45 @@ func (s *CrossControllerSuite) TestWatchControllerInfoError(c *gc.C) {
 	})
 	c.Assert(s.resources.Get("1"), gc.IsNil)
 }
+
+type stubControllerInfoGetter struct{}
+
+func (stubControllerInfoGetter) APIHostPortsForClients() ([]network.SpaceHostPorts, error) {
+	return []network.SpaceHostPorts{{
+		network.SpaceHostPort{
+			SpaceAddress: network.SpaceAddress{
+				MachineAddress: network.MachineAddress{
+					Value: "10.1.2.3",
+					Scope: network.ScopeCloudLocal,
+				},
+				SpaceID: "0",
+			},
+			NetPort: 50000,
+		},
+		network.SpaceHostPort{
+			SpaceAddress: network.SpaceAddress{
+				MachineAddress: network.MachineAddress{
+					Value: "host-name",
+					Scope: network.ScopePublic,
+				},
+				SpaceID: "0",
+			},
+			NetPort: 50000,
+		},
+	}}, nil
+}
+
+func (stubControllerInfoGetter) ControllerConfig() (controller.Config, error) {
+	return map[string]interface{}{
+		"ca-cert": "ca-cert",
+	}, nil
+}
+
+func (s *CrossControllerSuite) TestGetControllerInfo(c *gc.C) {
+	addrs, cert, err := controllerInfo(stubControllerInfoGetter{})
+	c.Assert(err, jc.ErrorIsNil)
+
+	// Public address is sorted first.
+	c.Check(addrs, jc.DeepEquals, []string{"host-name:50000", "10.1.2.3:50000"})
+	c.Check(cert, gc.Equals, "ca-cert")
+}

apiserver/facades/controller/crosscontroller/register.go

@@ -4,13 +4,13 @@
 package crosscontroller
 
 import (
+	jujucontroller "github.com/juju/juju/controller"
 	"reflect"
 
 	"github.com/juju/errors"
 
 	"github.com/juju/juju/apiserver/facade"
 	"github.com/juju/juju/core/network"
-	"github.com/juju/juju/state"
 )
 
 // Register is called to expose a package of facades onto a given registry.
@@ -40,7 +40,16 @@ func newStateCrossControllerAPI(ctx facade.Context) (*CrossControllerAPI, error)
 	)
 }
 
-func controllerInfo(st *state.State) ([]string, string, error) {
+// controllerInfoGetter indirects state for retrieving information
+// required for cross-controller communication.
+type controllerInfoGetter interface {
+	APIHostPortsForClients() ([]network.SpaceHostPorts, error)
+	ControllerConfig() (jujucontroller.Config, error)
+}
+
+// controllerInfo retrieves information required to communicate
+// with this controller - API addresses and the CA cert.
+func controllerInfo(st controllerInfoGetter) ([]string, string, error) {
 	apiHostPorts, err := st.APIHostPortsForClients()
 	if err != nil {
 		return nil, "", errors.Trace(err)