Support bases in bundles

This commit backports _some_ of the changes from the PR
juju#15725

However, instead of converting to bases at the edge, we convert to
series at the edge. This is because there are a lot of changes in later
versions that using bases throughout depends on which are not present in
3.1, which would require expensive backports

We also do NOT backport changes to GetChanges and GetChangesMapArgs, as
they are not required to backport this feature. This simplifies the
change significantly

api/common/charms/common.go

@@ -390,7 +390,7 @@ func (c *charmImpl) Revision() int {
 
 func convertCharmManifest(input *params.CharmManifest) (*charm.Manifest, error) {
 	if input == nil {
-		return &charm.Manifest{}, nil
+		return nil, nil
 	}
 	res := []charm.Base(nil)
 	for _, v := range input.Bases {

api/common/charms/common_test.go

@@ -189,7 +189,6 @@ func (s *suite) TestApplicationCharmInfo(c *gc.C) {
 			Name:           "foobar",
 			MinJujuVersion: version.MustParse("2.9.0"),
 		},
-		Manifest: &charm.Manifest{},
 	}
 	c.Assert(got, gc.DeepEquals, want)
 }

apiserver/facades/client/bundle/bundle.go

@@ -210,6 +210,7 @@ func (b *BundleAPI) GetChangesMapArgs(args params.BundleChangesParams) (params.B
 	}
 	return b.doGetBundleChangesMapArgs(args, vs, func(changes []bundlechanges.Change, results *params.BundleChangesMapArgsResults) error {
 		results.Changes = make([]*params.BundleChangesMapArgs, len(changes))
+		results.Errors = make([]string, len(changes))
 		for i, c := range changes {
 			args, err := c.Args()
 			if err != nil {

cmd/juju/application/deployer/bundlehandler.go

@@ -339,12 +339,13 @@ func (h *bundleHandler) resolveCharmsAndEndpoints() error {
 		}
 
 		var base corebase.Base
-		if spec.Series != "" {
-			var err error
+		if spec.Base != "" {
+			base, err = corebase.ParseBaseFromString(spec.Base)
+		} else if spec.Series != "" {
 			base, err = corebase.GetBaseFromSeries(spec.Series)
-			if err != nil {
-				return errors.Trace(err)
-			}
+		}
+		if err != nil {
+			return errors.Trace(err)
 		}
 
 		channel, origin, err := h.constructChannelAndOrigin(ch, base, spec.Channel, cons)

core/bundle/changes/changes.go

@@ -95,7 +95,10 @@ func FromData(config ChangesConfig) ([]Change, error) {
 
 	var addedMachines map[string]*AddMachineChange
 	if resolver.bundle.Type != kubernetes {
-		addedMachines = resolver.handleMachines()
+		addedMachines, err = resolver.handleMachines()
+		if err != nil {
+			return nil, errors.Trace(err)
+		}
 	}
 
 	deployedBundleApps := alreadyDeployedApplicationsFromBundle(model, config.Bundle.Applications)

core/bundle/changes/changes_test.go

@@ -900,6 +900,193 @@ func (s *changesSuite) TestSimpleBundle(c *gc.C) {
 	s.assertParseData(c, content, expected)
 }
 
+func (s *changesSuite) TestSimpleBundleWithBases(c *gc.C) {
+	content := `
+        applications:
+            mediawiki:
+                charm: ch:mediawiki
+                base: ubuntu@20.04
+                num_units: 1
+                expose: true
+                options:
+                    debug: false
+                annotations:
+                    gui-x: "609"
+                    gui-y: "-15"
+                resources:
+                    data: 3
+            mysql:
+                charm: ch:mysql
+                base: ubuntu@20.04
+                num_units: 1
+                resources:
+                  data: "./resources/data.tar"
+        default-base: ubuntu@22.04
+        relations:
+            - - mediawiki:db
+              - mysql:db
+        `
+	expected := []record{{
+		Id:     "addCharm-0",
+		Method: "addCharm",
+		Params: bundlechanges.AddCharmParams{
+			Charm:  "ch:mediawiki",
+			Series: "focal",
+		},
+		GUIArgs: []interface{}{"ch:mediawiki", "focal", ""},
+		Args: map[string]interface{}{
+			"charm":  "ch:mediawiki",
+			"series": "focal",
+		},
+	}, {
+		Id:     "deploy-1",
+		Method: "deploy",
+		Params: bundlechanges.AddApplicationParams{
+			Charm:       "$addCharm-0",
+			Application: "mediawiki",
+			Series:      "focal",
+			Options:     map[string]interface{}{"debug": false},
+			Resources:   map[string]int{"data": 3},
+		},
+		GUIArgs: []interface{}{
+			"$addCharm-0",
+			"focal",
+			"mediawiki",
+			map[string]interface{}{"debug": false},
+			"",
+			map[string]string{},
+			map[string]string{},
+			map[string]int{"data": 3},
+			0,
+			"",
+		},
+		Args: map[string]interface{}{
+			"application": "mediawiki",
+			"charm":       "$addCharm-0",
+			"options": map[string]interface{}{
+				"debug": false,
+			},
+			"resources": map[string]interface{}{
+				"data": float64(3),
+			},
+			"series": "focal",
+		},
+		Requires: []string{"addCharm-0"},
+	}, {
+		Id:     "expose-2",
+		Method: "expose",
+		Params: bundlechanges.ExposeParams{
+			Application: "$deploy-1",
+		},
+		GUIArgs: []interface{}{"$deploy-1", nil},
+		Args: map[string]interface{}{
+			"application": "$deploy-1",
+		},
+		Requires: []string{"deploy-1"},
+	}, {
+		Id:     "setAnnotations-3",
+		Method: "setAnnotations",
+		Params: bundlechanges.SetAnnotationsParams{
+			Id:          "$deploy-1",
+			EntityType:  bundlechanges.ApplicationType,
+			Annotations: map[string]string{"gui-x": "609", "gui-y": "-15"},
+		},
+		GUIArgs: []interface{}{
+			"$deploy-1",
+			"application",
+			map[string]string{"gui-x": "609", "gui-y": "-15"},
+		},
+		Args: map[string]interface{}{
+			"annotations": map[string]interface{}{
+				"gui-x": "609",
+				"gui-y": "-15",
+			},
+			"entity-type": "application",
+			"id":          "$deploy-1",
+		},
+		Requires: []string{"deploy-1"},
+	}, {
+		Id:     "addCharm-4",
+		Method: "addCharm",
+		Params: bundlechanges.AddCharmParams{
+			Charm:  "ch:mysql",
+			Series: "focal",
+		},
+		GUIArgs: []interface{}{"ch:mysql", "focal", ""},
+		Args: map[string]interface{}{
+			"charm":  "ch:mysql",
+			"series": "focal",
+		},
+	}, {
+		Id:     "deploy-5",
+		Method: "deploy",
+		Params: bundlechanges.AddApplicationParams{
+			Charm:          "$addCharm-4",
+			Application:    "mysql",
+			Series:         "focal",
+			LocalResources: map[string]string{"data": "./resources/data.tar"},
+		},
+		GUIArgs: []interface{}{
+			"$addCharm-4",
+			"focal",
+			"mysql",
+			map[string]interface{}{},
+			"",
+			map[string]string{},
+			map[string]string{},
+			map[string]int{},
+			0,
+			"",
+		},
+		Args: map[string]interface{}{
+			"application": "mysql",
+			"charm":       "$addCharm-4",
+			"local-resources": map[string]interface{}{
+				"data": "./resources/data.tar",
+			},
+			"series": "focal",
+		},
+		Requires: []string{"addCharm-4"},
+	}, {
+		Id:     "addRelation-6",
+		Method: "addRelation",
+		Params: bundlechanges.AddRelationParams{
+			Endpoint1: "$deploy-1:db",
+			Endpoint2: "$deploy-5:db",
+		},
+		GUIArgs: []interface{}{"$deploy-1:db", "$deploy-5:db"},
+		Args: map[string]interface{}{
+			"endpoint1": "$deploy-1:db",
+			"endpoint2": "$deploy-5:db",
+		},
+		Requires: []string{"deploy-1", "deploy-5"},
+	}, {
+		Id:     "addUnit-7",
+		Method: "addUnit",
+		Params: bundlechanges.AddUnitParams{
+			Application: "$deploy-1",
+		},
+		GUIArgs: []interface{}{"$deploy-1", nil},
+		Args: map[string]interface{}{
+			"application": "$deploy-1",
+		},
+		Requires: []string{"deploy-1"},
+	}, {
+		Id:     "addUnit-8",
+		Method: "addUnit",
+		Params: bundlechanges.AddUnitParams{
+			Application: "$deploy-5",
+		},
+		GUIArgs: []interface{}{"$deploy-5", nil},
+		Args: map[string]interface{}{
+			"application": "$deploy-5",
+		},
+		Requires: []string{"deploy-5"},
+	}}
+
+	s.assertParseData(c, content, expected)
+}
+
 func (s *changesSuite) TestSimpleBundleWithDevices(c *gc.C) {
 	content := `
         applications:

core/bundle/changes/handlers.go

@@ -33,7 +33,16 @@ type resolver struct {
 func (r *resolver) handleApplications() (map[string]string, error) {
 	add := r.changes.add
 	applications := r.bundle.Applications
-	defaultSeries := r.bundle.Series
+
+	var defaultSeries string
+	if r.bundle.Series != "" {
+		defaultSeries = r.bundle.Series
+	} else if r.bundle.DefaultBase != "" {
+		var err error
+		if defaultSeries, err = baseToSeries(r.bundle.DefaultBase); err != nil {
+			return nil, errors.Trace(err)
+		}
+	}
 	existing := r.model
 
 	charms := make(map[string]string, len(applications))
@@ -405,12 +414,21 @@ func equalStringSlice(a, b []string) bool {
 
 // handleMachines populates the change set with "addMachines" records.
 // This function also handles adding machine annotations.
-func (r *resolver) handleMachines() map[string]*AddMachineChange {
+func (r *resolver) handleMachines() (map[string]*AddMachineChange, error) {
 	add := r.changes.add
 	machines := r.bundle.Machines
-	defaultSeries := r.bundle.Series
 	existing := r.model
 
+	var defaultSeries string
+	if r.bundle.Series != "" {
+		defaultSeries = r.bundle.Series
+	} else if r.bundle.DefaultBase != "" {
+		var err error
+		if defaultSeries, err = baseToSeries(r.bundle.DefaultBase); err != nil {
+			return nil, errors.Trace(err)
+		}
+	}
+
 	addedMachines := make(map[string]*AddMachineChange, len(machines))
 	// Iterate over the map using its sorted keys so that results are
 	// deterministic and easier to test.
@@ -427,11 +445,15 @@ func (r *resolver) handleMachines() map[string]*AddMachineChange {
 		if machine == nil {
 			machine = &charm.MachineSpec{}
 		}
-		series := machine.Series
-		if series == "" {
-			series = defaultSeries
+		series := defaultSeries
+		if machine.Series != "" {
+			series = machine.Series
+		} else if machine.Base != "" {
+			var err error
+			if series, err = baseToSeries(machine.Base); err != nil {
+				return nil, errors.Trace(err)
+			}
 		}
-
 		var id string
 		var target string
 		var requires []string
@@ -469,7 +491,7 @@ func (r *resolver) handleMachines() map[string]*AddMachineChange {
 			}, requires...))
 		}
 	}
-	return addedMachines
+	return addedMachines, nil
 }
 
 // handleRelations populates the change set with "addRelation" records.
@@ -1140,11 +1162,22 @@ func (r *resolver) handleUnits(addedApplications map[string]string, addedMachine
 		machChangeIDs.Add(v.Id())
 	}
 
+	var defaultSeries string
+	if r.bundle.Series != "" {
+		defaultSeries = r.bundle.Series
+	} else if r.bundle.DefaultBase != "" {
+		var err error
+		defaultSeries, err = baseToSeries(r.bundle.DefaultBase)
+		if err != nil {
+			return errors.Trace(err)
+		}
+	}
+
 	processor := &unitProcessor{
 		add:                        r.changes.add,
 		existing:                   r.model,
 		bundle:                     r.bundle,
-		defaultSeries:              r.bundle.Series,
+		defaultSeries:              defaultSeries,
 		logger:                     r.logger,
 		addedApplications:          addedApplications,
 		addedMachines:              addedMachines,
@@ -1260,6 +1293,9 @@ func getSeries(application *charm.ApplicationSpec, defaultSeries string) (string
 	if application.Series != "" {
 		return application.Series, nil
 	}
+	if application.Base != "" {
+		return baseToSeries(application.Base)
+	}
 
 	// Handle local charm paths.
 	if charm.IsValidLocalCharmOrBundlePath(application.Charm) {
@@ -1295,6 +1331,18 @@ func getSeries(application *charm.ApplicationSpec, defaultSeries string) (string
 	return defaultSeries, nil
 }
 
+func baseToSeries(b string) (string, error) {
+	base, err := corebase.ParseBaseFromString(b)
+	if err != nil {
+		return "", errors.Trace(err)
+	}
+	series, err := corebase.GetSeriesFromBase(base)
+	if err != nil {
+		return "", errors.Trace(err)
+	}
+	return series, nil
+}
+
 // parseEndpoint creates an endpoint from its string representation.
 func parseEndpoint(e string) *endpoint {
 	parts := strings.SplitN(e, ":", 2)