[WIP] Integrate Fleetlock client with Locksmith

go.mod

@@ -6,15 +6,14 @@ require (
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf
 	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f
+	github.com/flatcar-linux/fleetlock v0.0.0-20210922150917-05e572675abd
 	github.com/godbus/dbus v4.1.0+incompatible // indirect
-	github.com/godbus/dbus/v5 v5.0.3
-	github.com/gogo/protobuf v1.3.1 // indirect
+	github.com/godbus/dbus/v5 v5.0.4
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/rkt/rkt v1.30.0
 	go.etcd.io/etcd v0.0.0-00010101000000-000000000000
-	go.uber.org/zap v1.16.0 // indirect
-	golang.org/x/net v0.0.0-20201031054903-ff519b6c9102
-	google.golang.org/grpc v1.33.2 // indirect
+	go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee // indirect
+	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4
 )
 
 replace (

lock/client.go

@@ -16,7 +16,6 @@ package lock
 
 // LockClient is a generic interface for a lock
 type LockClient interface {
-	Init() error
-	Get() (*Semaphore, error)
-	Set(*Semaphore) error
+	RecursiveLock() error
+	UnlockIfHeld() error
 }

lock/lock.go

@@ -14,78 +14,41 @@
 
 package lock
 
+import (
+	"errors"
+)
+
 // Lock takes care of locking in generic clients
 type Lock struct {
 	id     string
 	client LockClient
 }
 
+var (
+	// ErrExist is the error returned if a holder with the specified id
+	// is already holding the semaphore
+	ErrExist = errors.New("holder exists")
+	// ErrNotExist is the error returned if there is no holder with the
+	// specified id holding the semaphore
+	ErrNotExist = errors.New("holder does not exist")
+)
+
 // New returns a new lock with the provided arguments
 func New(id string, client LockClient) (lock *Lock) {
 	return &Lock{id, client}
 }
 
-func (l *Lock) store(f func(*Semaphore) error) (err error) {
-	sem, err := l.client.Get()
-	if err != nil {
-		return err
-	}
-
-	if err := f(sem); err != nil {
-		return err
-	}
-
-	err = l.client.Set(sem)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-// Get returns the current semaphore value
-// if the underlying client returns an error, Get passes it through
-func (l *Lock) Get() (sem *Semaphore, err error) {
-	sem, err = l.client.Get()
-	if err != nil {
-		return nil, err
-	}
-
-	return sem, nil
-}
-
-// SetMax sets the maximum number of holders the semaphore will allow
-// it returns the current semaphore and the previous maximum
-// if there is a problem getting or setting the semaphore, this function will
-// pass on errors from the underlying client
-func (l *Lock) SetMax(max int) (sem *Semaphore, oldMax int, err error) {
-	var (
-		semRet *Semaphore
-		old    int
-	)
-
-	return semRet, old, l.store(func(sem *Semaphore) error {
-		old = sem.Max
-		semRet = sem
-		return sem.SetMax(max)
-	})
-}
-
 // Lock adds this lock id as a holder to the semaphore
 // it will return an error if there is a problem getting or setting the
 // semaphore, or if the maximum number of holders has been reached, or if a lock
 // with this id is already a holder
 func (l *Lock) Lock() (err error) {
-	return l.store(func(sem *Semaphore) error {
-		return sem.Lock(l.id)
-	})
+	return l.client.RecursiveLock()
 }
 
 // Unlock removes this lock id as a holder of the semaphore
 // it returns an error if there is a problem getting or setting the semaphore,
 // or if this lock is not locked.
 func (l *Lock) Unlock() error {
-	return l.store(func(sem *Semaphore) error {
-		return sem.Unlock(l.id)
-	})
+	return l.client.UnlockIfHeld()
 }