ps: do not sync container

Do not sync containers with the runtime and the database when listing
containers.  It turns out to be extremely expensive and unnecessary.

The sync was needed since listing all containers from the database did
not populate their state.  Doing that, however, is much faster since we
already have a connection to the database.

This change makes listing 200 containers 2 times faster than before.

[NO NEW TESTS NEEDED]

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

libpod/boltdb_state.go

@@ -815,8 +815,6 @@ func (s *BoltState) UpdateContainer(ctr *Container) error {
 		return fmt.Errorf("container %s is in namespace %q, does not match our namespace %q: %w", ctr.ID(), ctr.config.Namespace, s.namespace, define.ErrNSMismatch)
 	}
 
-	newState := new(ContainerState)
-
 	ctrID := []byte(ctr.ID())
 
 	db, err := s.getDBCon()
@@ -825,43 +823,13 @@ func (s *BoltState) UpdateContainer(ctr *Container) error {
 	}
 	defer s.deferredCloseDBCon(db)
 
-	err = db.View(func(tx *bolt.Tx) error {
+	return db.View(func(tx *bolt.Tx) error {
 		ctrBucket, err := getCtrBucket(tx)
 		if err != nil {
 			return err
 		}
-
-		ctrToUpdate := ctrBucket.Bucket(ctrID)
-		if ctrToUpdate == nil {
-			ctr.valid = false
-			return fmt.Errorf("container %s does not exist in database: %w", ctr.ID(), define.ErrNoSuchCtr)
-		}
-
-		newStateBytes := ctrToUpdate.Get(stateKey)
-		if newStateBytes == nil {
-			return fmt.Errorf("container %s does not have a state key in DB: %w", ctr.ID(), define.ErrInternal)
-		}
-
-		if err := json.Unmarshal(newStateBytes, newState); err != nil {
-			return fmt.Errorf("unmarshalling container %s state: %w", ctr.ID(), err)
-		}
-
-		// backwards compat, previously we used a extra bucket for the netns so try to get it from there
-		netNSBytes := ctrToUpdate.Get(netNSKey)
-		if netNSBytes != nil && newState.NetNS == "" {
-			newState.NetNS = string(netNSBytes)
-		}
-
-		return nil
+		return s.getContainerStateDB(ctrID, ctr, ctrBucket)
 	})
-	if err != nil {
-		return err
-	}
-
-	// New state compiled successfully, swap it into the current state
-	ctr.state = newState
-
-	return nil
 }
 
 // SaveContainer saves a container's current state in the database

libpod/boltdb_state_internal.go

@@ -428,11 +428,43 @@ func (s *BoltState) getContainerConfigFromDB(id []byte, config *ContainerConfig,
 	return nil
 }
 
+func (s *BoltState) getContainerStateDB(id []byte, ctr *Container, ctrsBkt *bolt.Bucket) error {
+	newState := new(ContainerState)
+	ctrToUpdate := ctrsBkt.Bucket(id)
+	if ctrToUpdate == nil {
+		ctr.valid = false
+		return fmt.Errorf("container %s does not exist in database: %w", ctr.ID(), define.ErrNoSuchCtr)
+	}
+
+	newStateBytes := ctrToUpdate.Get(stateKey)
+	if newStateBytes == nil {
+		return fmt.Errorf("container %s does not have a state key in DB: %w", ctr.ID(), define.ErrInternal)
+	}
+
+	if err := json.Unmarshal(newStateBytes, newState); err != nil {
+		return fmt.Errorf("unmarshalling container %s state: %w", ctr.ID(), err)
+	}
+
+	// backwards compat, previously we used a extra bucket for the netns so try to get it from there
+	netNSBytes := ctrToUpdate.Get(netNSKey)
+	if netNSBytes != nil && newState.NetNS == "" {
+		newState.NetNS = string(netNSBytes)
+	}
+
+	// New state compiled successfully, swap it into the current state
+	ctr.state = newState
+	return nil
+}
+
 func (s *BoltState) getContainerFromDB(id []byte, ctr *Container, ctrsBkt *bolt.Bucket) error {
 	if err := s.getContainerConfigFromDB(id, ctr.config, ctrsBkt); err != nil {
 		return err
 	}
 
+	if err := s.getContainerStateDB(id, ctr, ctrsBkt); err != nil {
+		return err
+	}
+
 	// Get the lock
 	lock, err := s.runtime.lockManager.RetrieveLock(ctr.config.LockID)
 	if err != nil {

libpod/container_api.go

@@ -829,10 +829,6 @@ func (c *Container) Batch(batchFunc func(*Container) error) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	if err := c.syncContainer(); err != nil {
-		return err
-	}
-
 	newCtr := new(Container)
 	newCtr.config = c.config
 	newCtr.state = c.state