diff options
| -rw-r--r-- | libpod/runtime.go | 13 | ||||
| -rw-r--r-- | libpod/runtime_ctr.go | 5 | ||||
| -rw-r--r-- | libpod/shutdown/handler.go | 131 | ||||
| -rw-r--r-- | pkg/api/server/server.go | 24 | ||||
| -rw-r--r-- | pkg/domain/infra/abi/terminal/sigproxy_linux.go | 5 |
5 files changed, 167 insertions, 11 deletions
diff --git a/libpod/runtime.go b/libpod/runtime.go index 7da8b181f..ccd920ab0 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 +} diff --git a/pkg/api/server/server.go b/pkg/api/server/server.go index 355a46fb7..64008767b 100644 --- a/pkg/api/server/server.go +++ b/pkg/api/server/server.go @@ -7,7 +7,6 @@ import ( "net" "net/http" "os" - "os/signal" goRuntime "runtime" "strings" "sync" @@ -15,6 +14,7 @@ import ( "time" "github.com/containers/podman/v2/libpod" + "github.com/containers/podman/v2/libpod/shutdown" "github.com/containers/podman/v2/pkg/api/handlers" "github.com/containers/podman/v2/pkg/api/server/idle" "github.com/coreos/go-systemd/v22/activation" @@ -180,8 +180,17 @@ func setupSystemd() { // Serve starts responding to HTTP requests. func (s *APIServer) Serve() error { setupSystemd() - sigChan := make(chan os.Signal, 1) - signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM) + + // Start the shutdown signal handler. + if err := shutdown.Start(); err != nil { + return err + } + if err := shutdown.Register("server", func(sig os.Signal) error { + return s.Shutdown() + }); err != nil { + return err + } + errChan := make(chan error, 1) go func() { @@ -217,14 +226,7 @@ func (s *APIServer) Serve() error { errChan <- nil }() - select { - case err := <-errChan: - return err - case sig := <-sigChan: - logrus.Infof("APIServer terminated by signal %v", sig) - } - - return nil + return <-errChan } // Shutdown is a clean shutdown waiting on existing clients diff --git a/pkg/domain/infra/abi/terminal/sigproxy_linux.go b/pkg/domain/infra/abi/terminal/sigproxy_linux.go index f484e926c..0c586cf5c 100644 --- a/pkg/domain/infra/abi/terminal/sigproxy_linux.go +++ b/pkg/domain/infra/abi/terminal/sigproxy_linux.go @@ -5,12 +5,17 @@ import ( "syscall" "github.com/containers/podman/v2/libpod" + "github.com/containers/podman/v2/libpod/shutdown" "github.com/containers/podman/v2/pkg/signal" "github.com/sirupsen/logrus" ) // ProxySignals ... func ProxySignals(ctr *libpod.Container) { + // Stop catching the shutdown signals (SIGINT, SIGTERM) - they're going + // to the container now. + shutdown.Stop() + sigBuffer := make(chan os.Signal, 128) signal.CatchAll(sigBuffer) |