diff --git a/cmd/info.go b/cmd/info.go
index f6cb3b0..6df1d7c 100644
--- a/cmd/info.go
+++ b/cmd/info.go
@@ -58,6 +58,7 @@ func (i info) Run(context wisski_distillery.Context) error {
context.Printf("GraphDB Password: %v\n", instance.GraphDBPassword)
context.Printf("Running: %v\n", info.Running)
+ context.Printf("Locked: %v\n", info.Locked)
context.Printf("Last Rebuild: %v\n", info.LastRebuild.String())
context.Printf("Skip Prefixes: %v\n", info.NoPrefixes)
diff --git a/cmd/instance_lock.go b/cmd/instance_lock.go
new file mode 100644
index 0000000..dee0d65
--- /dev/null
+++ b/cmd/instance_lock.go
@@ -0,0 +1,67 @@
+package cmd
+
+import (
+ wisski_distillery "github.com/FAU-CDI/wisski-distillery"
+ "github.com/FAU-CDI/wisski-distillery/internal/core"
+ "github.com/tkw1536/goprogram/exit"
+)
+
+// InstanceLock is then 'instance_lock' command
+var InstanceLock wisski_distillery.Command = instanceLock{}
+
+type instanceLock struct {
+ Lock bool `short:"l" long:"lock" description:"Lock the provided WissKI instance"`
+ Unlock bool `short:"u" long:"unlock" description:"Unlock the provided WissKI instance"`
+ Positionals struct {
+ Slug string `positional-arg-name:"SLUG" required:"1-1" description:"slug of instance to lock or unlock"`
+ } `positional-args:"true"`
+}
+
+func (instanceLock) Description() wisski_distillery.Description {
+ return wisski_distillery.Description{
+ Requirements: core.Requirements{
+ NeedsDistillery: true,
+ },
+ Command: "instance_lock",
+ Description: "Locks or unlocks a WissKI instance",
+ }
+}
+
+var errLockUnlockExcluded = exit.Error{
+ Message: "Exactly one of `--lock` and `--unlock` must be provied",
+ ExitCode: exit.ExitCommandArguments,
+}
+
+func (l instanceLock) AfterParse() error {
+ if l.Lock == l.Unlock {
+ return errLockUnlockExcluded
+ }
+ return nil
+}
+
+var errNotUnlock = exit.Error{
+ Message: "Unable to unlock instance: Not locked",
+ ExitCode: exit.ExitCommandArguments,
+}
+
+func (l instanceLock) Run(context wisski_distillery.Context) error {
+ instance, err := context.Environment.Instances().WissKI(l.Positionals.Slug)
+ if err != nil {
+ return err
+ }
+
+ if l.Unlock {
+ if !instance.Unlock() {
+ return errNotUnlock
+ }
+ context.Println("unlocked")
+ return nil
+ }
+
+ if err := instance.TryLock(); err != nil {
+ return err
+ }
+
+ context.Println("locked")
+ return nil
+}
diff --git a/cmd/purge.go b/cmd/purge.go
index e5f5e5e..6989b49 100644
--- a/cmd/purge.go
+++ b/cmd/purge.go
@@ -102,6 +102,12 @@ func (p purge) Run(context wisski_distillery.Context) error {
context.EPrintln(err)
}
+ // remove the filesystem
+ logging.LogMessage(context.IOStream, "Remove lock data", instance.FilesystemBase)
+ if !instance.Unlock() {
+ context.EPrintln("instance was not locked")
+ }
+
logging.LogMessage(context.IOStream, "Instance %s has been purged", slug)
return nil
}
diff --git a/cmd/wdcli/main.go b/cmd/wdcli/main.go
index 626e38b..0dd0b19 100644
--- a/cmd/wdcli/main.go
+++ b/cmd/wdcli/main.go
@@ -37,6 +37,7 @@ func init() {
// instance management
wdcli.Register(cmd.Ls)
wdcli.Register(cmd.Info)
+ wdcli.Register(cmd.InstanceLock)
// instance tasks
wdcli.Register(cmd.Shell)
diff --git a/internal/component/info/html/instance.html b/internal/component/info/html/instance.html
index 8e5952a..1ef9c9e 100644
--- a/internal/component/info/html/instance.html
+++ b/internal/component/info/html/instance.html
@@ -20,6 +20,7 @@
Excluded from Resolver: {{ .Info.NoPrefixes }}
Running: {{ .Info.Running }}
+ Locked: {{ .Info.Locked }}
Created: {{ .Instance.Created.Format "2006-01-02T15:04:05Z07:00" }}
diff --git a/internal/component/instances/wisski_lock.go b/internal/component/instances/wisski_lock.go
new file mode 100644
index 0000000..12db452
--- /dev/null
+++ b/internal/component/instances/wisski_lock.go
@@ -0,0 +1,47 @@
+package instances
+
+import (
+ "errors"
+
+ "github.com/FAU-CDI/wisski-distillery/internal/models"
+)
+
+var ErrLocked = errors.New("instance is locked")
+
+// TryLock attemps to lock this WissKI
+// If this is not possible, returns ErrLocked
+func (wisski WissKI) TryLock() error {
+ table, err := wisski.instances.SQL.QueryTable(true, models.LockTable)
+ if err != nil {
+ return ErrLocked
+ }
+
+ result := table.FirstOrCreate(&models.Lock{}, models.Lock{Slug: wisski.Slug})
+ locked := result.Error == nil && result.RowsAffected == 1
+
+ if !locked {
+ return ErrLocked
+ }
+ return nil
+}
+
+func (wisski WissKI) IsLocked() (locked bool) {
+ table, err := wisski.instances.SQL.QueryTable(true, models.LockTable)
+ if err != nil {
+ return false
+ }
+
+ // check if this instance is locked
+ table.Select("count(*) > 0").Where("slug = ?", wisski.Slug).Find(&locked)
+ return
+}
+
+// Unlock unlocks this WissKI instance and returns if it succeeded
+func (wisski WissKI) Unlock() bool {
+ table, err := wisski.instances.SQL.QueryTable(true, models.LockTable)
+ if err != nil {
+ return false
+ }
+ result := table.Where("slug = ?", wisski.Slug).Delete(&models.Lock{})
+ return result.Error == nil && result.RowsAffected == 1
+}
diff --git a/internal/component/instances/wisski_stack.go b/internal/component/instances/wisski_stack.go
index cf5812c..ea80bb5 100644
--- a/internal/component/instances/wisski_stack.go
+++ b/internal/component/instances/wisski_stack.go
@@ -70,6 +70,11 @@ func (wisski *WissKI) setLastRebuild() error {
//
// It also logs the current time into the metadata belonging to this instance.
func (wisski *WissKI) Build(stream stream.IOStream, start bool) error {
+ if err := wisski.TryLock(); err != nil {
+ return err
+ }
+ defer wisski.Unlock()
+
barrel := wisski.Barrel()
var context component.InstallationContext
diff --git a/internal/component/instances/wisski_status.go b/internal/component/instances/wisski_status.go
index ce51912..19a2521 100644
--- a/internal/component/instances/wisski_status.go
+++ b/internal/component/instances/wisski_status.go
@@ -16,6 +16,8 @@ type WissKIInfo struct {
Slug string // slug
URL string // complete URL, including http(s)
+ Locked bool // Is this instance currently locked?
+
// Information about the running instance
Running bool
LastRebuild time.Time
@@ -48,6 +50,12 @@ func (wisski *WissKI) Info(quick bool) (info WissKIInfo, err error) {
return
})
+ // quick check if this instance is locked
+ group.Go(func() (err error) {
+ info.Locked = wisski.IsLocked()
+ return nil
+ })
+
// slower checks for extra properties.
// these might execute php code or require additional database queries.
if !quick {
diff --git a/internal/component/snapshots/snapshot.go b/internal/component/snapshots/snapshot.go
index c83f92c..83e9eaa 100644
--- a/internal/component/snapshots/snapshot.go
+++ b/internal/component/snapshots/snapshot.go
@@ -44,6 +44,21 @@ type Snapshot struct {
// Snapshot creates a new snapshot of this instance into dest
func (snapshots *Manager) NewSnapshot(instance instances.WissKI, io stream.IOStream, desc SnapshotDescription) (snapshot Snapshot) {
+
+ logging.LogMessage(io, "Locking instance")
+ if err := instance.TryLock(); err != nil {
+ io.EPrintln(err)
+ logging.LogMessage(io, "Aborting snapshot creation")
+
+ return Snapshot{
+ ErrPanic: err,
+ }
+ }
+ defer func() {
+ logging.LogMessage(io, "Unlocking instance")
+ instance.Unlock()
+ }()
+
// setup the snapshot
snapshot.Description = desc
snapshot.Instance = instance.Instance
diff --git a/internal/component/sql/update.go b/internal/component/sql/update.go
index 4200095..2258d65 100644
--- a/internal/component/sql/update.go
+++ b/internal/component/sql/update.go
@@ -96,6 +96,11 @@ func (sql *SQL) Update(io stream.IOStream) error {
&models.Export{},
models.ExportTable,
},
+ {
+ "lock",
+ &models.Lock{},
+ models.LockTable,
+ },
}
// migrate all of the tables!
diff --git a/internal/models/lock.go b/internal/models/lock.go
new file mode 100644
index 0000000..76ae07e
--- /dev/null
+++ b/internal/models/lock.go
@@ -0,0 +1,11 @@
+package models
+
+// LockTable is the name of the table the 'Metadatum' model is stored in.
+const LockTable = "locks"
+
+// Lock represents a log on WissKI Instances
+type Lock struct {
+ Pk uint `gorm:"column:pk;primaryKey"`
+
+ Slug string `gorm:"column:slug;not null"` // slug of instance
+}