Merge branch '605-prevent-deletion-defaults' into 'dle-4-0'

fix: prevent deletion of dataset pool and main branch (#605)

See merge request postgres-ai/database-lab!999

Author: bogdan-ts

engine/internal/cloning/base.go

@@ -30,7 +30,6 @@ import (
 	"gitlab.com/postgres-ai/database-lab/v3/pkg/log"
 	"gitlab.com/postgres-ai/database-lab/v3/pkg/models"
 	"gitlab.com/postgres-ai/database-lab/v3/pkg/util"
-	"gitlab.com/postgres-ai/database-lab/v3/pkg/util/branching"
 	"gitlab.com/postgres-ai/database-lab/v3/pkg/util/pglog"
 )
 
@@ -190,10 +189,7 @@ func (c *Base) CreateClone(cloneRequest *types.CloneCreateRequest) (*models.Clon
 			Username: cloneRequest.DB.Username,
 			DBName:   cloneRequest.DB.DBName,
 		},
-	}
-
-	if clone.Branch == "" {
-		clone.Branch = branching.DefaultBranch
+		Revision: cloneRequest.Revision,
 	}
 
 	w := NewCloneWrapper(clone, createdAt)

engine/internal/provision/mode_local.go

@@ -229,18 +229,6 @@ func (p *Provisioner) StopSession(session *resources.Session, clone *models.Clon
 		return errors.Wrap(err, "failed to stop container")
 	}
 
-	if clone.Revision == branching.DefaultRevision {
-		// Destroy clone revision
-		if err := fsm.DestroyClone(clone.Branch, name, clone.Revision); err != nil {
-			return errors.Wrap(err, "failed to destroy clone")
-		}
-
-		// Destroy clone dataset
-		if err := fsm.DestroyDataset(fsm.Pool().CloneDataset(clone.Branch, name)); err != nil {
-			return errors.Wrap(err, "failed to destroy clone dataset")
-		}
-	}
-
 	if err := p.FreePort(session.Port); err != nil {
 		return errors.Wrap(err, "failed to unbind a port")
 	}

engine/internal/provision/resources/pool.go

@@ -84,6 +84,11 @@ func (p *Pool) CloneLocation(branchName, name string, revision int) string {
 	return path.Join(p.MountDir, p.PoolDirName, branching.BranchDir, branchName, name, branching.RevisionSegment(revision))
 }
 
+// CloneRevisionLocation returns a path to the clone revisions.
+func (p *Pool) CloneRevisionLocation(branchName, name string) string {
+	return path.Join(p.MountDir, p.PoolDirName, branching.BranchDir, branchName, name)
+}
+
 // SocketCloneDir returns a path to the socket clone directory.
 func (p *Pool) SocketCloneDir(name string) string {
 	return path.Join(p.SocketDir(), name)

engine/internal/srv/branch.go

@@ -523,6 +523,11 @@ func (s *Server) deleteBranch(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if branchName == branching.DefaultBranch {
+		api.SendBadRequestError(w, r, fmt.Sprintf("cannot delete default branch: %s", branching.DefaultBranch))
+		return
+	}
+
 	snapshotID, ok := repo.Branches[branchName]
 	if !ok {
 		api.SendBadRequestError(w, r, "branch not found: "+branchName)

engine/internal/srv/routes.go

@@ -229,6 +229,14 @@ func (s *Server) deleteSnapshot(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Prevent deletion of the last snapshot in the pool.
+	snapshotCnt := len(fsm.SnapshotList())
+
+	if fullDataset, _, found := strings.Cut(snapshotID, "@"); found && fullDataset == poolName && snapshotCnt == 1 {
+		api.SendBadRequestError(w, r, "cannot destroy the last snapshot in the pool")
+		return
+	}
+
 	// Check if snapshot exists.
 	if _, err := fsm.GetSnapshotProperties(snapshotID); err != nil {
 		if runnerError, ok := err.(runners.RunnerError); ok {
@@ -322,7 +330,7 @@ func (s *Server) deleteSnapshot(w http.ResponseWriter, r *http.Request) {
 
 	if snapshotProperties.Clones == "" && snapshot.NumClones == 0 {
 		// Destroy dataset if there are no related objects
-		if fullDataset, _, found := strings.Cut(snapshotID, "@"); found {
+		if fullDataset, _, found := strings.Cut(snapshotID, "@"); found && fullDataset != poolName {
 			if err = fsm.DestroyDataset(fullDataset); err != nil {
 				api.SendBadRequestError(w, r, err.Error())
 				return
@@ -504,6 +512,19 @@ func (s *Server) createClone(w http.ResponseWriter, r *http.Request) {
 		}
 
 		cloneRequest.Snapshot = &types.SnapshotCloneFieldRequest{ID: snapshotID}
+	} else {
+		cloneRequest.Branch = branching.DefaultBranch
+	}
+
+	if cloneRequest.ID != "" {
+		fsm, err := s.getFSManagerForBranch(cloneRequest.Branch)
+		if err != nil {
+			api.SendBadRequestError(w, r, err.Error())
+			return
+		}
+
+		// Check if there is any clone revision under the dataset.
+		cloneRequest.Revision = findMaxCloneRevision(fsm.Pool().CloneRevisionLocation(cloneRequest.Branch, cloneRequest.ID))
 	}
 
 	newClone, err := s.Cloning.CreateClone(cloneRequest)
@@ -533,6 +554,39 @@ func (s *Server) createClone(w http.ResponseWriter, r *http.Request) {
 	log.Dbg(fmt.Sprintf("Clone ID=%s is being created", newClone.ID))
 }
 
+func findMaxCloneRevision(path string) int {
+	files, err := os.ReadDir(path)
+	if err != nil {
+		log.Err(err)
+		return 0
+	}
+
+	maxIndex := -1
+
+	for _, file := range files {
+		if !file.IsDir() {
+			continue
+		}
+
+		revisionIndex, ok := strings.CutPrefix(file.Name(), "r")
+		if !ok {
+			continue
+		}
+
+		index, err := strconv.Atoi(revisionIndex)
+		if err != nil {
+			log.Err(err)
+			continue
+		}
+
+		if index > maxIndex {
+			maxIndex = index
+		}
+	}
+
+	return maxIndex + 1
+}
+
 func (s *Server) destroyClone(w http.ResponseWriter, r *http.Request) {
 	cloneID := mux.Vars(r)["id"]
 

engine/pkg/client/dblabapi/types/clone.go

@@ -13,6 +13,7 @@ type CloneCreateRequest struct {
 	Snapshot  *SnapshotCloneFieldRequest `json:"snapshot"`
 	ExtraConf map[string]string          `json:"extra_conf"`
 	Branch    string                     `json:"branch"`
+	Revision  int                        `json:"-"`
 }
 
 // CloneUpdateRequest represents params of an update request.