Add basic skeleton of libpod runtime

Signed-off-by: Matthew Heon <mheon@redhat.com>

libpod/runtime.go

@@ -1,26 +1,135 @@
 package libpod
 
 import (
+	"fmt"
+	"sync"
+
+	"github.com/containers/image/types"
 	"github.com/containers/storage"
 	"github.com/kubernetes-incubator/cri-o/libpod/ctr"
 	"github.com/kubernetes-incubator/cri-o/libpod/pod"
+	"github.com/kubernetes-incubator/cri-o/server/apparmor"
+	"github.com/kubernetes-incubator/cri-o/server/seccomp"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/ulule/deepcopier"
 )
 
-// Runtime API
-
 // A RuntimeOption is a functional option which alters the Runtime created by
 // NewRuntime
 type RuntimeOption func(*Runtime) error
 
 // Runtime is the core libpod runtime
 type Runtime struct {
-	// TODO populate
+	config          *RuntimeConfig
+	store           storage.Store
+	imageContext    *types.SystemContext
+	apparmorEnabled bool
+	seccompEnabled  bool
+	valid           bool
+	lock            sync.RWMutex
 }
 
+// RuntimeConfig contains configuration options used to set up the runtime
+type RuntimeConfig struct {
+	StorageConfig         storage.StoreOptions
+	ImageDefaultTransport string
+	InsecureRegistries    []string
+	Registries            []string
+	SignaturePolicyPath   string
+	RuntimePath           string
+	ConmonPath            string
+	ConmonEnvVars         []string
+	CgroupManager         string
+	SelinuxEnabled        bool
+	PidsLimit             int64
+}
+
+var (
+	defaultRuntimeConfig = RuntimeConfig{
+		// Leave this empty so containers/storage will use its defaults
+		StorageConfig:         storage.StoreOptions{},
+		ImageDefaultTransport: "docker://",
+		RuntimePath:           "/usr/bin/runc",
+		ConmonPath:            "/usr/local/libexec/crio/conmon",
+		ConmonEnvVars: []string{
+			"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+		},
+		CgroupManager:  "cgroupfs",
+		SelinuxEnabled: false,
+		PidsLimit:      1024,
+	}
+)
+
 // NewRuntime creates a new container runtime
+// Options can be passed to override the default configuration for the runtime
 func NewRuntime(options ...RuntimeOption) (*Runtime, error) {
-	return nil, ctr.ErrNotImplemented
+	runtime := new(Runtime)
+	runtime.config = new(RuntimeConfig)
+
+	// Copy the default configuration
+	deepcopier.Copy(defaultRuntimeConfig).To(runtime.config)
+
+	// Overwrite it with user-given configuration options
+	for _, opt := range options {
+		if err := opt(runtime); err != nil {
+			return nil, errors.Wrapf(err, "error configuring runtime")
+		}
+	}
+
+	// Set up containers/storage
+	store, err := storage.GetStore(runtime.config.StorageConfig)
+	if err != nil {
+		return nil, err
+	}
+	runtime.store = store
+
+	// Set up containers/image
+	runtime.imageContext = &types.SystemContext{
+		SignaturePolicyPath: runtime.config.SignaturePolicyPath,
+	}
+
+	runtime.seccompEnabled = seccomp.IsEnabled()
+	runtime.apparmorEnabled = apparmor.IsEnabled()
+
+	// Mark the runtime as valid - ready to be used, cannot be modified
+	// further
+	runtime.valid = true
+
+	return runtime, nil
+}
+
+// GetConfig returns a copy of the configuration used by the runtime
+func (r *Runtime) GetConfig() *RuntimeConfig {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	if !r.valid {
+		return nil
+	}
+
+	config := new(RuntimeConfig)
+
+	// Copy so the caller won't be able to modify the actual config
+	deepcopier.Copy(r.config).To(config)
+
+	return config
+}
+
+// Shutdown shuts down the runtime and associated containers and storage
+// If force is true, containers and mounted storage will be shut down before
+// cleaning up; if force is false, an error will be returned if there are
+// still containers running or mounted
+func (r *Runtime) Shutdown(force bool) error {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if !r.valid {
+		return fmt.Errorf("runtime has already been shut down")
+	}
+
+	_, err := r.store.Shutdown(force)
+	return err
 }
 
 // Container API