Add structure for new exec session tracking to DB

As part of the rework of exec sessions, we need to address them
independently of containers. In the new API, we need to be able
to fetch them by their ID, regardless of what container they are
associated with. Unfortunately, our existing exec sessions are
tied to individual containers; there's no way to tell what
container a session belongs to and retrieve it without getting
every exec session for every container.

This adds a pointer to the container an exec session is
associated with to the database. The sessions themselves are
still stored in the container.

Exec-related APIs have been restructured to work with the new
database representation. The originally monolithic API has been
split into a number of smaller calls to allow more fine-grained
control of lifecycle. Support for legacy exec sessions has been
retained, but in a deprecated fashion; we should remove this in
a few releases.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 13 insertions, 0 deletions

diff --git a/libpod/define/errors.go b/libpod/define/errors.go
index b79cf08dc..3ba343789 100644
--- a/libpod/define/errors.go
+++ b/libpod/define/errors.go
@@ -20,6 +20,10 @@ var (
 	// ErrNoSuchVolume indicates the requested volume does not exist
 	ErrNoSuchVolume = errors.New("no such volume")
 
+	// ErrNoSuchExecSession indicates that the requested exec session does
+	// not exist.
+	ErrNoSuchExecSession = errors.New("no such exec session")
+
 	// ErrCtrExists indicates a container with the same name or ID already
 	// exists
 	ErrCtrExists = errors.New("container already exists")
@@ -29,10 +33,16 @@ var (
 	ErrImageExists = errors.New("image already exists")
 	// ErrVolumeExists indicates a volume with the same name already exists
 	ErrVolumeExists = errors.New("volume already exists")
+	// ErrExecSessionExists indicates an exec session with the same ID
+	// already exists.
+	ErrExecSessionExists = errors.New("exec session already exists")
 
 	// ErrCtrStateInvalid indicates a container is in an improper state for
 	// the requested operation
 	ErrCtrStateInvalid = errors.New("container state improper")
+	// ErrExecSessionStateInvalid indicates that an exec session is in an
+	// improper state for the requested operation
+	ErrExecSessionStateInvalid = errors.New("exec session state improper")
 	// ErrVolumeBeingUsed indicates that a volume is being used by at least one container
 	ErrVolumeBeingUsed = errors.New("volume is being used")
 
@@ -90,6 +100,9 @@ var (
 	// ErrVolumeRemoved indicates that the volume has already been removed and
 	// no further operations can be performed on it
 	ErrVolumeRemoved = errors.New("volume has already been removed")
+	// ErrExecSessionRemoved indicates that the exec session has already
+	// been removed and no further operations can be performed on it.
+	ErrExecSessionRemoved = errors.New("exec session has already been removed")
 
 	// ErrDBClosed indicates that the connection to the state database has
 	// already been closed