Merge pull request juju#16850 from manadart/dqlite-endpoint-bindings-…

…minus-default-space

juju#16850

Functionality for endpoint bindings uses a method in state called `DefaultEndpointBindingSpace`, which takes the space name configured for `default-binding` in model configuration, and looks up its ID.

Here, we add some vice code to remove the lookup, ensuring that we always just use the `alpha` space ID.

This eases the work of migrating the space domain to Dqlite.

## QA steps

Passing tests.

## Documentation changes

No, but noted in [risk register](https://docs.google.com/spreadsheets/d/1vSd3s0asNtpENdeC3tPkEo5mDja4inS5KwjCFxhyE5I).

## Links

**Jira card:** JUJU-5367

apiserver/common/modelmanagerinterface.go

@@ -77,7 +77,6 @@ type ModelManagerBackend interface {
 	AddSpace(string, network.Id, []string) (*state.Space, error)
 	AllEndpointBindingsSpaceNames() (set.Strings, error)
 	ConstraintsBySpaceName(string) ([]*state.Constraints, error)
-	DefaultEndpointBindingSpace() (string, error)
 	// TODO(nvinuesa): This method is necessary only until the spaces
 	// migration to dqlite is finished:
 	Space(id string) (*state.Space, error)

apiserver/facades/client/application/deployrepository.go

@@ -66,7 +66,6 @@ type DeployFromRepositoryState interface {
 	services.StateBackend
 
 	network.SpaceLookup
-	DefaultEndpointBindingSpace() (string, error)
 	Space(id string) (*state.Space, error)
 }
 

environs/space/spaces.go

@@ -32,9 +32,6 @@ type ReloadSpacesState interface {
 	// ConstraintsBySpaceName returns all Constraints that include a positive
 	// or negative space constraint for the input space name.
 	ConstraintsBySpaceName(string) ([]Constraints, error)
-	// DefaultEndpointBindingSpace returns the current space ID to be used for
-	// the default endpoint binding.
-	DefaultEndpointBindingSpace() (string, error)
 	// AllEndpointBindingsSpaceNames returns a set of spaces names for all the
 	// endpoint bindings.
 	AllEndpointBindingsSpaceNames() (set.Strings, error)
@@ -185,10 +182,10 @@ func (s *ProviderSpaces) DeleteSpaces() ([]string, error) {
 		return nil, nil
 	}
 
-	defaultEndpointBinding, err := s.state.DefaultEndpointBindingSpace()
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
+	// TODO (manadart 2024-01-29): The alpha space ID here is scaffolding and
+	// should be replaced with the configured model default space upon
+	// migrating this logic to Dqlite.
+	defaultEndpointBinding := network.AlphaSpaceId
 
 	allEndpointBindings, err := s.state.AllEndpointBindingsSpaceNames()
 	if err != nil {

environs/space/spaces_test.go

@@ -205,7 +205,6 @@ func (s *providerSpacesSuite) TestDeleteSpaces(c *gc.C) {
 	defer ctrl.Finish()
 
 	mockState := NewMockReloadSpacesState(ctrl)
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("2", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings(), nil)
 	mockState.EXPECT().ConstraintsBySpaceName("1").Return(nil, nil)
 	mockState.EXPECT().Remove("1").Return(nil)
@@ -229,7 +228,6 @@ func (s *providerSpacesSuite) TestDeleteSpacesMatchesAlphaSpace(c *gc.C) {
 	defer ctrl.Finish()
 
 	mockState := NewMockReloadSpacesState(ctrl)
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("1", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings(), nil)
 
 	provider := NewProviderSpaces(mockState)
@@ -248,11 +246,12 @@ func (s *providerSpacesSuite) TestDeleteSpacesMatchesAlphaSpace(c *gc.C) {
 }
 
 func (s *providerSpacesSuite) TestDeleteSpacesMatchesDefaultBindingSpace(c *gc.C) {
+	c.Skip("The default space is always alpha due to scaffolding in service of Dqlite migration.")
+
 	ctrl := gomock.NewController(c)
 	defer ctrl.Finish()
 
 	mockState := NewMockReloadSpacesState(ctrl)
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("1", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings(), nil)
 
 	provider := NewProviderSpaces(mockState)
@@ -275,7 +274,6 @@ func (s *providerSpacesSuite) TestDeleteSpacesContainedInAllEndpointBindings(c *
 	defer ctrl.Finish()
 
 	mockState := NewMockReloadSpacesState(ctrl)
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("2", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings("1"), nil)
 
 	provider := NewProviderSpaces(mockState)
@@ -298,7 +296,6 @@ func (s *providerSpacesSuite) TestDeleteSpacesContainsConstraintsSpace(c *gc.C)
 	defer ctrl.Finish()
 
 	mockState := NewMockReloadSpacesState(ctrl)
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("2", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings(), nil)
 	mockState.EXPECT().ConstraintsBySpaceName("1").Return([]Constraints{struct{}{}}, nil)
 
@@ -358,7 +355,6 @@ func (s *providerSpacesSuite) TestProviderSpacesRun(c *gc.C) {
 		},
 	})
 
-	mockState.EXPECT().DefaultEndpointBindingSpace().Return("2", nil)
 	mockState.EXPECT().AllEndpointBindingsSpaceNames().Return(set.NewStrings(), nil)
 	mockState.EXPECT().ConstraintsBySpaceName("space1").Return(nil, nil)
 

state/endpoint_bindings.go

@@ -97,11 +97,10 @@ func (b *Bindings) Merge(mergeWith map[string]string, meta *charm.Meta) (bool, e
 
 	defaultBinding, mergeOK := b.bindingsMap[defaultEndpointName]
 	if !mergeOK {
-		var err error
-		defaultBinding, err = b.st.DefaultEndpointBindingSpace()
-		if err != nil {
-			return false, errors.Trace(err)
-		}
+		// TODO (manadart 2024-01-29): The alpha space ID here is scaffolding and
+		// should be replaced with the configured model default space upon
+		// migrating this logic to Dqlite.
+		defaultBinding = network.AlphaSpaceId
 	}
 	if newDefaultBinding, newOk := mergeMap[defaultEndpointName]; newOk {
 		// new default binding supersedes the old default binding
@@ -447,47 +446,20 @@ func (b *Bindings) validateForCharm(charmMeta *charm.Meta) error {
 	return nil
 }
 
-// DefaultEndpointBindingSpace returns the current space ID to be used for
-// the default endpoint binding.
-func (st *State) DefaultEndpointBindingSpace() (string, error) {
-	model, err := st.Model()
-	if err != nil {
-		return "", errors.Trace(err)
-	}
-
-	cfg, err := model.Config()
-	if err != nil {
-		return "", errors.Trace(err)
-	}
-
-	defaultBinding := network.AlphaSpaceId
-
-	space, err := st.SpaceByName(cfg.DefaultSpace())
-	if err != nil && !errors.Is(err, errors.NotFound) {
-		return "", errors.Trace(err)
-	}
-	if err == nil {
-		defaultBinding = space.Id()
-	}
-
-	return defaultBinding, nil
-}
-
 // DefaultEndpointBindingsForCharm populates a bindings map containing each
 // endpoint of the given charm metadata (relation name or extra-binding name)
 // bound to an empty space.
-func DefaultEndpointBindingsForCharm(st EndpointBinding, charmMeta *charm.Meta) (map[string]string, error) {
-	defaultBindingSpaceID, err := st.DefaultEndpointBindingSpace()
-	if err != nil {
-		return nil, err
-	}
+// TODO (manadart 2024-01-29): The alpha space ID here is scaffolding and
+// should be replaced with the configured model default space upon
+// migrating this logic to Dqlite.
+func DefaultEndpointBindingsForCharm(_ EndpointBinding, charmMeta *charm.Meta) (map[string]string, error) {
 	allRelations := charmMeta.CombinedRelations()
 	bindings := make(map[string]string, len(allRelations)+len(charmMeta.ExtraBindings))
 	for name := range allRelations {
-		bindings[name] = defaultBindingSpaceID
+		bindings[name] = network.AlphaSpaceId
 	}
 	for name := range charmMeta.ExtraBindings {
-		bindings[name] = defaultBindingSpaceID
+		bindings[name] = network.AlphaSpaceId
 	}
 	return bindings, nil
 }
@@ -498,7 +470,6 @@ func DefaultEndpointBindingsForCharm(st EndpointBinding, charmMeta *charm.Meta)
 //go:generate go run go.uber.org/mock/mockgen -package mocks -destination mocks/endpointbinding_mock.go github.com/juju/juju/state EndpointBinding
 type EndpointBinding interface {
 	network.SpaceLookup
-	DefaultEndpointBindingSpace() (string, error)
 	Space(id string) (*Space, error)
 }
 

state/endpoint_bindings_test.go

@@ -287,6 +287,7 @@ func (s *bindingsSuite) TestMergeBindings(c *gc.C) {
 }
 
 func (s *bindingsSuite) TestMergeWithModelConfigNonDefaultSpace(c *gc.C) {
+	c.Skip("The default space is always alpha due to scaffolding in service of Dqlite migration.")
 	err := s.Model.UpdateModelConfig(map[string]interface{}{"default-space": s.appsSpace.Name()}, nil)
 	c.Assert(err, jc.ErrorIsNil)
 
@@ -310,20 +311,6 @@ func (s *bindingsSuite) TestMergeWithModelConfigNonDefaultSpace(c *gc.C) {
 	c.Check(isModified, gc.Equals, true)
 }
 
-func (s *bindingsSuite) TestDefaultEndpointBindingSpaceNotDefault(c *gc.C) {
-	err := s.Model.UpdateModelConfig(map[string]interface{}{"default-space": s.clientSpace.Name()}, nil)
-	c.Assert(err, jc.ErrorIsNil)
-	id, err := s.State.DefaultEndpointBindingSpace()
-	c.Assert(err, jc.ErrorIsNil)
-	c.Assert(id, gc.Equals, s.clientSpace.Id())
-}
-
-func (s *bindingsSuite) TestDefaultEndpointBindingSpaceDefault(c *gc.C) {
-	id, err := s.State.DefaultEndpointBindingSpace()
-	c.Assert(err, jc.ErrorIsNil)
-	c.Assert(id, gc.Equals, network.AlphaSpaceId)
-}
-
 func (s *bindingsSuite) copyMap(input map[string]string) map[string]string {
 	output := make(map[string]string, len(input))
 	for key, value := range input {