Merge pull request #14466 from mheon/fix_9075

Improve robustness of `podman system reset`

3 files changed, 144 insertions, 3 deletions

diff --git a/libpod/options.go b/libpod/options.go
index a02c05537..4b6803c3f 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -435,6 +435,21 @@ func WithDefaultInfraCommand(cmd string) RuntimeOption {
 	}
 }
 
+// WithReset instructs libpod to reset all storage to factory defaults.
+// All containers, pods, volumes, images, and networks will be removed.
+// All directories created by Libpod will be removed.
+func WithReset() RuntimeOption {
+	return func(rt *Runtime) error {
+		if rt.valid {
+			return define.ErrRuntimeFinalized
+		}
+
+		rt.doReset = true
+
+		return nil
+	}
+}
+
 // WithRenumber instructs libpod to perform a lock renumbering while
 // initializing. This will handle migrations from early versions of libpod with
 // file locks to newer versions with SHM locking, as well as changes in the
diff --git a/libpod/reset.go b/libpod/reset.go
index 28d0ee3f6..30eab50fb 100644
--- a/libpod/reset.go
+++ b/libpod/reset.go
@@ -17,8 +17,78 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// removeAllDirs removes all Podman storage directories. It is intended to be
+// used as a backup for reset() when that function cannot be used due to
+// failures in initializing libpod.
+// It does not expect that all the directories match what is in use by Podman,
+// as this is a common failure point for `system reset`. As such, our ability to
+// interface with containers and pods is somewhat limited.
+// This function assumes that we do not have a working c/storage store.
+func (r *Runtime) removeAllDirs() error {
+	var lastErr error
+
+	// Grab the runtime alive lock.
+	// This ensures that no other Podman process can run while we are doing
+	// a reset, so no race conditions with containers/pods/etc being created
+	// while we are resetting storage.
+	// TODO: maybe want a helper for getting the path? This is duped from
+	// runtime.go
+	runtimeAliveLock := filepath.Join(r.config.Engine.TmpDir, "alive.lck")
+	aliveLock, err := storage.GetLockfile(runtimeAliveLock)
+	if err != nil {
+		logrus.Errorf("Lock runtime alive lock %s: %v", runtimeAliveLock, err)
+	} else {
+		aliveLock.Lock()
+		defer aliveLock.Unlock()
+	}
+
+	// We do not have a store - so we can't really try and remove containers
+	// or pods or volumes...
+	// Try and remove the directories, in hopes that they are unmounted.
+	// This is likely to fail but it's the best we can do.
+
+	// Volume path
+	if err := os.RemoveAll(r.config.Engine.VolumePath); err != nil {
+		lastErr = errors.Wrapf(err, "removing volume path")
+	}
+
+	// Tmpdir
+	if err := os.RemoveAll(r.config.Engine.TmpDir); err != nil {
+		if lastErr != nil {
+			logrus.Errorf("Reset: %v", lastErr)
+		}
+		lastErr = errors.Wrapf(err, "removing tmp dir")
+	}
+
+	// Runroot
+	if err := os.RemoveAll(r.storageConfig.RunRoot); err != nil {
+		if lastErr != nil {
+			logrus.Errorf("Reset: %v", lastErr)
+		}
+		lastErr = errors.Wrapf(err, "removing run root")
+	}
+
+	// Static dir
+	if err := os.RemoveAll(r.config.Engine.StaticDir); err != nil {
+		if lastErr != nil {
+			logrus.Errorf("Reset: %v", lastErr)
+		}
+		lastErr = errors.Wrapf(err, "removing static dir")
+	}
+
+	// Graph root
+	if err := os.RemoveAll(r.storageConfig.GraphRoot); err != nil {
+		if lastErr != nil {
+			logrus.Errorf("Reset: %v", lastErr)
+		}
+		lastErr = errors.Wrapf(err, "removing graph root")
+	}
+
+	return lastErr
+}
+
 // Reset removes all storage
-func (r *Runtime) Reset(ctx context.Context) error {
+func (r *Runtime) reset(ctx context.Context) error {
 	var timeout *uint
 	pods, err := r.GetAllPods()
 	if err != nil {
diff --git a/libpod/runtime.go b/libpod/runtime.go
index e268c2d17..10c6d21c5 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -96,6 +96,10 @@ type Runtime struct {
 	// This bool is just needed so that we can set it for netavark interface.
 	syslog bool
 
+	// doReset indicates that the runtime should perform a system reset.
+	// All Podman files will be removed.
+	doReset bool
+
 	// doRenumber indicates that the runtime should perform a lock renumber
 	// during initialization.
 	// Once the runtime has been initialized and returned, this variable is
@@ -235,6 +239,11 @@ func newRuntimeFromConfig(conf *config.Config, options ...RuntimeOption) (*Runti
 
 	runtime.config.CheckCgroupsAndAdjustConfig()
 
+	// If resetting storage, do *not* return a runtime.
+	if runtime.doReset {
+		return nil, nil
+	}
+
 	return runtime, nil
 }
 
@@ -305,6 +314,13 @@ func makeRuntime(runtime *Runtime) (retErr error) {
 	}
 	runtime.conmonPath = cPath
 
+	if runtime.noStore && runtime.doReset {
+		return errors.Wrapf(define.ErrInvalidArg, "cannot perform system reset if runtime is not creating a store")
+	}
+	if runtime.doReset && runtime.doRenumber {
+		return errors.Wrapf(define.ErrInvalidArg, "cannot perform system reset while renumbering locks")
+	}
+
 	// Make the static files directory if it does not exist
 	if err := os.MkdirAll(runtime.config.Engine.StaticDir, 0700); err != nil {
 		// The directory is allowed to exist
@@ -339,6 +355,20 @@ func makeRuntime(runtime *Runtime) (retErr error) {
 	// Grab config from the database so we can reset some defaults
 	dbConfig, err := runtime.state.GetDBConfig()
 	if err != nil {
+		if runtime.doReset {
+			// We can at least delete the DB and the static files
+			// directory.
+			// Can't safely touch anything else because we aren't
+			// sure of other directories.
+			if err := runtime.state.Close(); err != nil {
+				logrus.Errorf("Closing database connection: %v", err)
+			} else {
+				if err := os.RemoveAll(runtime.config.Engine.StaticDir); err != nil {
+					logrus.Errorf("Removing static files directory %v: %v", runtime.config.Engine.StaticDir, err)
+				}
+			}
+		}
+
 		return errors.Wrapf(err, "error retrieving runtime configuration from database")
 	}
 
@@ -372,7 +402,13 @@ func makeRuntime(runtime *Runtime) (retErr error) {
 	// Validate our config against the database, now that we've set our
 	// final storage configuration
 	if err := runtime.state.ValidateDBConfig(runtime); err != nil {
-		return err
+		// If we are performing a storage reset: continue on with a
+		// warning. Otherwise we can't `system reset` after a change to
+		// the core paths.
+		if !runtime.doReset {
+			return err
+		}
+		logrus.Errorf("Runtime paths differ from those stored in database, storage reset may not remove all files")
 	}
 
 	if err := runtime.state.SetNamespace(runtime.config.Engine.Namespace); err != nil {
@@ -394,6 +430,14 @@ func makeRuntime(runtime *Runtime) (retErr error) {
 	} else if runtime.noStore {
 		logrus.Debug("No store required. Not opening container store.")
 	} else if err := runtime.configureStore(); err != nil {
+		// Make a best-effort attempt to clean up if performing a
+		// storage reset.
+		if runtime.doReset {
+			if err := runtime.removeAllDirs(); err != nil {
+				logrus.Errorf("Removing libpod directories: %v", err)
+			}
+		}
+
 		return err
 	}
 	defer func() {
@@ -575,6 +619,18 @@ func makeRuntime(runtime *Runtime) (retErr error) {
 		return err
 	}
 
+	// If we're resetting storage, do it now.
+	// We will not return a valid runtime.
+	// TODO: Plumb this context out so it can be set.
+	if runtime.doReset {
+		// Mark the runtime as valid, so normal functionality "mostly"
+		// works and we can use regular functions to remove
+		// ctrs/pods/etc
+		runtime.valid = true
+
+		return runtime.reset(context.Background())
+	}
+
 	// If we're renumbering locks, do it now.
 	// It breaks out of normal runtime init, and will not return a valid
 	// runtime.
@@ -818,7 +874,7 @@ func (r *Runtime) DeferredShutdown(force bool) {
 // still containers running or mounted
 func (r *Runtime) Shutdown(force bool) error {
 	if !r.valid {
-		return define.ErrRuntimeStopped
+		return nil
 	}
 
 	if r.workerChannel != nil {