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-rw-r--r--libpod/runtime.go13
-rw-r--r--libpod/runtime_ctr.go5
-rw-r--r--libpod/shutdown/handler.go131
3 files changed, 149 insertions, 0 deletions
diff --git a/libpod/runtime.go b/libpod/runtime.go
index 6d5ea9c34..792492db6 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -17,6 +17,7 @@ import (
"github.com/containers/podman/v2/libpod/events"
"github.com/containers/podman/v2/libpod/image"
"github.com/containers/podman/v2/libpod/lock"
+ "github.com/containers/podman/v2/libpod/shutdown"
"github.com/containers/podman/v2/pkg/cgroups"
"github.com/containers/podman/v2/pkg/registries"
"github.com/containers/podman/v2/pkg/rootless"
@@ -174,9 +175,21 @@ func newRuntimeFromConfig(ctx context.Context, conf *config.Config, options ...R
}
}
+ if err := shutdown.Start(); err != nil {
+ return nil, errors.Wrapf(err, "error starting shutdown signal handler")
+ }
+
if err := makeRuntime(ctx, runtime); err != nil {
return nil, err
}
+
+ if err := shutdown.Register("libpod", func(sig os.Signal) error {
+ os.Exit(1)
+ return nil
+ }); err != nil {
+ logrus.Errorf("Error registering shutdown handler for libpod: %v", err)
+ }
+
return runtime, nil
}
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index 51b4c5f03..de73a9ff3 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -12,6 +12,7 @@ import (
"github.com/containers/common/pkg/config"
"github.com/containers/podman/v2/libpod/define"
"github.com/containers/podman/v2/libpod/events"
+ "github.com/containers/podman/v2/libpod/shutdown"
"github.com/containers/podman/v2/pkg/cgroups"
"github.com/containers/podman/v2/pkg/rootless"
"github.com/containers/storage"
@@ -149,6 +150,10 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
return nil, err
}
+ // Inhibit shutdown until creation succeeds
+ shutdown.Inhibit()
+ defer shutdown.Uninhibit()
+
// Allocate a lock for the container
lock, err := r.lockManager.AllocateLock()
if err != nil {
diff --git a/libpod/shutdown/handler.go b/libpod/shutdown/handler.go
new file mode 100644
index 000000000..87538dec9
--- /dev/null
+++ b/libpod/shutdown/handler.go
@@ -0,0 +1,131 @@
+package shutdown
+
+import (
+ "os"
+ "os/signal"
+ "sync"
+ "syscall"
+
+ "github.com/pkg/errors"
+ "github.com/sirupsen/logrus"
+)
+
+var (
+ stopped bool
+ sigChan chan os.Signal
+ cancelChan chan bool
+ // Definitions of all on-shutdown handlers
+ handlers map[string]func(os.Signal) error
+ // Ordering that on-shutdown handlers will be invoked.
+ handlerOrder []string
+ shutdownInhibit sync.RWMutex
+)
+
+// Start begins handling SIGTERM and SIGINT and will run the given on-signal
+// handlers when one is called. This can be cancelled by calling Stop().
+func Start() error {
+ if sigChan != nil {
+ // Already running, do nothing.
+ return nil
+ }
+
+ sigChan = make(chan os.Signal, 1)
+ cancelChan = make(chan bool, 1)
+ stopped = false
+
+ signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+ go func() {
+ select {
+ case <-cancelChan:
+ signal.Stop(sigChan)
+ close(sigChan)
+ close(cancelChan)
+ stopped = true
+ return
+ case sig := <-sigChan:
+ logrus.Infof("Received shutdown signal %v, terminating!", sig)
+ shutdownInhibit.Lock()
+ for _, name := range handlerOrder {
+ handler, ok := handlers[name]
+ if !ok {
+ logrus.Errorf("Shutdown handler %s definition not found!", name)
+ continue
+ }
+ logrus.Infof("Invoking shutdown handler %s", name)
+ if err := handler(sig); err != nil {
+ logrus.Errorf("Error running shutdown handler %s: %v", name, err)
+ }
+ }
+ shutdownInhibit.Unlock()
+ return
+ }
+ }()
+
+ return nil
+}
+
+// Stop the shutdown signal handler.
+func Stop() error {
+ if cancelChan == nil {
+ return errors.New("shutdown signal handler has not yet been started")
+ }
+ if stopped {
+ return nil
+ }
+
+ cancelChan <- true
+
+ return nil
+}
+
+// Temporarily inhibit signals from shutting down Libpod.
+func Inhibit() {
+ shutdownInhibit.RLock()
+}
+
+// Stop inhibiting signals from shutting down Libpod.
+func Uninhibit() {
+ shutdownInhibit.RUnlock()
+}
+
+// Register registers a function that will be executed when Podman is terminated
+// by a signal. Handlers are invoked LIFO - the last handler registered is the
+// first run.
+func Register(name string, handler func(os.Signal) error) error {
+ if handlers == nil {
+ handlers = make(map[string]func(os.Signal) error)
+ }
+
+ if _, ok := handlers[name]; ok {
+ return errors.Errorf("handler with name %s already exists", name)
+ }
+
+ handlers[name] = handler
+ handlerOrder = append([]string{name}, handlerOrder...)
+
+ return nil
+}
+
+// Unregister un-registers a given shutdown handler.
+func Unregister(name string) error {
+ if handlers == nil {
+ return nil
+ }
+
+ if _, ok := handlers[name]; !ok {
+ return nil
+ }
+
+ delete(handlers, name)
+
+ newOrder := []string{}
+ for _, checkName := range handlerOrder {
+ if checkName != name {
+ newOrder = append(newOrder, checkName)
+ }
+ }
+ handlerOrder = newOrder
+
+ return nil
+}