CMS: Create local implementation of cloud migration for dev use (#86637)

* add developer mode property to config

* create cms stub

* cleanup

* implement and wire up gcom stub

* fix errors

* don't document the flag

pkg/services/cloudmigration/cloudmigrationimpl/gcomstub.go

@@ -0,0 +1,60 @@
+package cloudmigrationimpl
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+
+	"github.com/grafana/grafana/pkg/services/gcom"
+	"github.com/grafana/grafana/pkg/util"
+)
+
+type gcomStub struct {
+	policies map[string]gcom.AccessPolicy
+}
+
+func (client *gcomStub) GetInstanceByID(ctx context.Context, requestID string, instanceID string) (gcom.Instance, error) {
+	id, err := strconv.Atoi(instanceID)
+	if err != nil {
+		return gcom.Instance{}, fmt.Errorf("parsing instanceID: %w", err)
+	}
+	return gcom.Instance{
+		ID:          id,
+		Slug:        "stubinstance",
+		RegionSlug:  "fake-region",
+		ClusterSlug: "fake-cluser",
+	}, nil
+}
+
+func (client *gcomStub) CreateAccessPolicy(ctx context.Context, params gcom.CreateAccessPolicyParams, payload gcom.CreateAccessPolicyPayload) (gcom.AccessPolicy, error) {
+	randStr := fmt.Sprintf("random-policy-%s", util.GenerateShortUID())
+	policy := gcom.AccessPolicy{
+		ID:   randStr,
+		Name: randStr,
+	}
+	client.policies[policy.ID] = policy
+	return policy, nil
+}
+
+func (client *gcomStub) DeleteAccessPolicy(ctx context.Context, params gcom.DeleteAccessPolicyParams) (bool, error) {
+	delete(client.policies, params.AccessPolicyID)
+	return true, nil
+}
+
+func (client *gcomStub) ListAccessPolicies(ctx context.Context, params gcom.ListAccessPoliciesParams) ([]gcom.AccessPolicy, error) {
+	items := make([]gcom.AccessPolicy, 0)
+	for _, v := range client.policies {
+		items = append(items, v)
+	}
+	return items, nil
+}
+
+func (client *gcomStub) CreateToken(ctx context.Context, params gcom.CreateTokenParams, payload gcom.CreateTokenPayload) (gcom.Token, error) {
+	token := gcom.Token{
+		ID:             fmt.Sprintf("random-token-%s", util.GenerateShortUID()),
+		Name:           payload.Name,
+		AccessPolicyID: payload.AccessPolicyID,
+		Token:          fmt.Sprintf("completely_fake_token_%s", util.GenerateShortUID()),
+	}
+	return token, nil
+}