1 files changed, 189 insertions, 0 deletions
diff --git a/libpod/oci_missing.go b/libpod/oci_missing.go
new file mode 100644
index 000000000..d4524cd34
--- /dev/null
+++ b/libpod/oci_missing.go
@@ -0,0 +1,189 @@
+package libpod
+
+import (
+	"fmt"
+	"path/filepath"
+	"sync"
+
+	"github.com/containers/libpod/libpod/define"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	// Only create each missing runtime once.
+	// Creation makes error messages we don't want to duplicate.
+	missingRuntimes map[string]*MissingRuntime
+	// We need a lock for this
+	missingRuntimesLock sync.Mutex
+)
+
+// MissingRuntime is used when the OCI runtime requested by the container is
+// missing (not installed or not in the configuration file).
+type MissingRuntime struct {
+	// Name is the name of the missing runtime. Will be used in errors.
+	name string
+	// exitsDir is the directory for exit files.
+	exitsDir string
+}
+
+// Get a new MissingRuntime for the given name.
+// Requires a libpod Runtime so we can make a sane path for the exits dir.
+func getMissingRuntime(name string, r *Runtime) (OCIRuntime, error) {
+	missingRuntimesLock.Lock()
+	defer missingRuntimesLock.Unlock()
+
+	if missingRuntimes == nil {
+		missingRuntimes = make(map[string]*MissingRuntime)
+	}
+
+	runtime, ok := missingRuntimes[name]
+	if ok {
+		return runtime, nil
+	}
+
+	// Once for each missing runtime, we want to error.
+	logrus.Errorf("OCI Runtime %s is in use by a container, but is not available (not in configuration file or not installed)", name)
+
+	newRuntime := new(MissingRuntime)
+	newRuntime.name = name
+	newRuntime.exitsDir = filepath.Join(r.config.TmpDir, "exits")
+
+	missingRuntimes[name] = newRuntime
+
+	return newRuntime, nil
+}
+
+// Name is the name of the missing runtime
+func (r *MissingRuntime) Name() string {
+	return fmt.Sprintf("%s (missing/not available)", r.name)
+}
+
+// Path is not available as the runtime is missing
+func (r *MissingRuntime) Path() string {
+	return "(missing/not available)"
+}
+
+// CreateContainer is not available as the runtime is missing
+func (r *MissingRuntime) CreateContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) error {
+	return r.printError()
+}
+
+// UpdateContainerStatus is not available as the runtime is missing
+func (r *MissingRuntime) UpdateContainerStatus(ctr *Container) error {
+	return r.printError()
+}
+
+// StartContainer is not available as the runtime is missing
+func (r *MissingRuntime) StartContainer(ctr *Container) error {
+	return r.printError()
+}
+
+// KillContainer is not available as the runtime is missing
+// TODO: We could attempt to unix.Kill() the PID as recorded in the state if we
+// really want to smooth things out? Won't be perfect, but if the container has
+// a PID namespace it could be enough?
+func (r *MissingRuntime) KillContainer(ctr *Container, signal uint, all bool) error {
+	return r.printError()
+}
+
+// StopContainer is not available as the runtime is missing
+func (r *MissingRuntime) StopContainer(ctr *Container, timeout uint, all bool) error {
+	return r.printError()
+}
+
+// DeleteContainer is not available as the runtime is missing
+func (r *MissingRuntime) DeleteContainer(ctr *Container) error {
+	return r.printError()
+}
+
+// PauseContainer is not available as the runtime is missing
+func (r *MissingRuntime) PauseContainer(ctr *Container) error {
+	return r.printError()
+}
+
+// UnpauseContainer is not available as the runtime is missing
+func (r *MissingRuntime) UnpauseContainer(ctr *Container) error {
+	return r.printError()
+}
+
+// ExecContainer is not available as the runtime is missing
+func (r *MissingRuntime) ExecContainer(ctr *Container, sessionID string, options *ExecOptions) (int, chan error, error) {
+	return -1, nil, r.printError()
+}
+
+// ExecStopContainer is not available as the runtime is missing.
+// TODO: We can also investigate using unix.Kill() on the PID of the exec
+// session here if we want to make stopping containers possible. Won't be
+// perfect, though.
+func (r *MissingRuntime) ExecStopContainer(ctr *Container, sessionID string, timeout uint) error {
+	return r.printError()
+}
+
+// ExecContainerCleanup is not available as the runtime is missing
+func (r *MissingRuntime) ExecContainerCleanup(ctr *Container, sessionID string) error {
+	return r.printError()
+}
+
+// CheckpointContainer is not available as the runtime is missing
+func (r *MissingRuntime) CheckpointContainer(ctr *Container, options ContainerCheckpointOptions) error {
+	return r.printError()
+}
+
+// SupportsCheckpoint returns false as checkpointing requires a working runtime
+func (r *MissingRuntime) SupportsCheckpoint() bool {
+	return false
+}
+
+// SupportsJSONErrors returns false as there is no runtime to give errors
+func (r *MissingRuntime) SupportsJSONErrors() bool {
+	return false
+}
+
+// SupportsNoCgroups returns false as there is no runtime to create containers
+func (r *MissingRuntime) SupportsNoCgroups() bool {
+	return false
+}
+
+// AttachSocketPath does not work as there is no runtime to attach to.
+// (Theoretically we could follow ExitFilePath but there is no guarantee the
+// container is running and thus has an attach socket...)
+func (r *MissingRuntime) AttachSocketPath(ctr *Container) (string, error) {
+	return "", r.printError()
+}
+
+// ExecAttachSocketPath does not work as there is no runtime to attach to.
+// (Again, we could follow ExitFilePath, but no guarantee there is an existing
+// and running exec session)
+func (r *MissingRuntime) ExecAttachSocketPath(ctr *Container, sessionID string) (string, error) {
+	return "", r.printError()
+}
+
+// ExitFilePath returns the exit file path for containers.
+// Here, we mimic what ConmonOCIRuntime does, because there is a chance that the
+// container in question is still running happily (config file modified to
+// remove a runtime, for example). We can't find the runtime to do anything to
+// the container, but Conmon should still place an exit file for it.
+func (r *MissingRuntime) ExitFilePath(ctr *Container) (string, error) {
+	if ctr == nil {
+		return "", errors.Wrapf(define.ErrInvalidArg, "must provide a valid container to get exit file path")
+	}
+	return filepath.Join(r.exitsDir, ctr.ID()), nil
+}
+
+// RuntimeInfo returns information on the missing runtime
+func (r *MissingRuntime) RuntimeInfo() (map[string]interface{}, error) {
+	info := make(map[string]interface{})
+	info["OCIRuntime"] = map[string]interface{}{
+		"name":    r.name,
+		"path":    "missing",
+		"package": "missing",
+		"version": "missing",
+	}
+	return info, nil
+}
+
+// Return an error indicating the runtime is missing
+func (r *MissingRuntime) printError() error {
+	return errors.Wrapf(define.ErrOCIRuntimeNotFound, "runtime %s is missing", r.name)
+}