Comment more packages to pass go lint

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

client.go

@@ -300,7 +300,7 @@ func (c *Client) Push(ctx context.Context, ref string, desc ocispec.Descriptor,
 			m.Lock()
 			manifestStack = append(manifestStack, desc)
 			m.Unlock()
-			return nil, images.StopHandler
+			return nil, images.ErrStopHandler
 		default:
 			return nil, nil
 		}

content/local/store.go

@@ -36,7 +36,7 @@ type store struct {
 	root string
 }
 
-// NewServer returns a local content store
+// NewStore returns a local content store
 func NewStore(root string) (content.Store, error) {
 	if err := os.MkdirAll(filepath.Join(root, "ingest"), 0777); err != nil && !os.IsExist(err) {
 		return nil, err
@@ -383,8 +383,8 @@ func (s *store) Abort(ctx context.Context, ref string) error {
 	return nil
 }
 
-func (cs *store) blobPath(dgst digest.Digest) string {
+func (s *store) blobPath(dgst digest.Digest) string {
-	return filepath.Join(cs.root, "blobs", dgst.Algorithm().String(), dgst.Hex())
+	return filepath.Join(s.root, "blobs", dgst.Algorithm().String(), dgst.Hex())
 }
 
 func (s *store) ingestRoot(ref string) string {

design/snapshots.md

@@ -137,7 +137,7 @@ We get back a list of mounts from `Snapshotter.Prepare`, with the `key`
 identifying the active snapshot. Mount this to the temporary location with the
 following:
 
-	if err := MountAll(mounts, tmpDir); err != nil { ... }
+	if err := mount.All(mounts, tmpDir); err != nil { ... }
 
 Once the mounts are performed, our temporary location is ready to capture
 a diff. In practice, this works similar to a filesystem transaction. The

differ/differ.go

@@ -25,7 +25,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.DiffPlugin,
 		ID:   "walking",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.ContentPlugin,
 			plugin.MetadataPlugin,
 		},
@@ -81,7 +81,7 @@ func (s *walkingDiff) Apply(ctx context.Context, desc ocispec.Descriptor, mounts
 	}
 	defer os.RemoveAll(dir)
 
-	if err := mount.MountAll(mounts, dir); err != nil {
+	if err := mount.All(mounts, dir); err != nil {
 		return emptyDesc, errors.Wrap(err, "failed to mount")
 	}
 	defer mount.Unmount(dir, 0)
@@ -149,12 +149,12 @@ func (s *walkingDiff) DiffMounts(ctx context.Context, lower, upper []mount.Mount
 	}
 	defer os.RemoveAll(bDir)
 
-	if err := mount.MountAll(lower, aDir); err != nil {
+	if err := mount.All(lower, aDir); err != nil {
 		return emptyDesc, errors.Wrap(err, "failed to mount")
 	}
 	defer mount.Unmount(aDir, 0)
 
-	if err := mount.MountAll(upper, bDir); err != nil {
+	if err := mount.All(upper, bDir); err != nil {
 		return emptyDesc, errors.Wrap(err, "failed to mount")
 	}
 	defer mount.Unmount(bDir, 0)

images/handlers.go

@@ -14,37 +14,40 @@ import (
 )
 
 var (
-	// SkipDesc is used to skip processing of a descriptor and
+	// ErrSkipDesc is used to skip processing of a descriptor and
 	// its descendants.
-	SkipDesc = fmt.Errorf("skip descriptor")
+	ErrSkipDesc = fmt.Errorf("skip descriptor")
 
-	// StopHandler is used to signify that the descriptor
+	// ErrStopHandler is used to signify that the descriptor
 	// has been handled and should not be handled further.
 	// This applies only to a single descriptor in a handler
 	// chain and does not apply to descendant descriptors.
-	StopHandler = fmt.Errorf("stop handler")
+	ErrStopHandler = fmt.Errorf("stop handler")
 )
 
+// Handler handles image manifests
 type Handler interface {
 	Handle(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error)
 }
 
+// HandlerFunc function implementing the Handler interface
 type HandlerFunc func(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error)
 
+// Handle image manifests
 func (fn HandlerFunc) Handle(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error) {
 	return fn(ctx, desc)
 }
 
 // Handlers returns a handler that will run the handlers in sequence.
 //
-// A handler may return `StopHandler` to stop calling additional handlers
+// A handler may return `ErrStopHandler` to stop calling additional handlers
 func Handlers(handlers ...Handler) HandlerFunc {
 	return func(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error) {
 		var children []ocispec.Descriptor
 		for _, handler := range handlers {
 			ch, err := handler.Handle(ctx, desc)
 			if err != nil {
-				if errors.Cause(err) == StopHandler {
+				if errors.Cause(err) == ErrStopHandler {
 					break
 				}
 				return nil, err
@@ -67,7 +70,7 @@ func Walk(ctx context.Context, handler Handler, descs ...ocispec.Descriptor) err
 
 		children, err := handler.Handle(ctx, desc)
 		if err != nil {
-			if errors.Cause(err) == SkipDesc {
+			if errors.Cause(err) == ErrSkipDesc {
 				continue // don't traverse the children.
 			}
 			return err
@@ -87,7 +90,7 @@ func Walk(ctx context.Context, handler Handler, descs ...ocispec.Descriptor) err
 // If the handler decode subresources, they will be visited, as well.
 //
 // Handlers for siblings are run in parallel on the provided descriptors. A
-// handler may return `SkipDesc` to signal to the dispatcher to not traverse
+// handler may return `ErrSkipDesc` to signal to the dispatcher to not traverse
 // any children.
 //
 // Typically, this function will be used with `FetchHandler`, often composed
@@ -104,7 +107,7 @@ func Dispatch(ctx context.Context, handler Handler, descs ...ocispec.Descriptor)
 
 			children, err := handler.Handle(ctx, desc)
 			if err != nil {
-				if errors.Cause(err) == SkipDesc {
+				if errors.Cause(err) == ErrSkipDesc {
 					return nil // don't traverse the children.
 				}
 				return err

images/image.go

@@ -21,6 +21,7 @@ type Image struct {
 	CreatedAt, UpdatedAt time.Time
 }
 
+// Store and interact with images
 type Store interface {
 	Get(ctx context.Context, name string) (Image, error)
 	List(ctx context.Context, filters ...string) ([]Image, error)
@@ -69,6 +70,7 @@ func (image *Image) Size(ctx context.Context, provider content.Provider, platfor
 	}), ChildrenHandler(provider, platform)), image.Target)
 }
 
+// Manifest returns the manifest for an image.
 func Manifest(ctx context.Context, provider content.Provider, image ocispec.Descriptor, platform string) (ocispec.Manifest, error) {
 	var (
 		matcher platforms.Matcher
@@ -177,7 +179,7 @@ func Platforms(ctx context.Context, provider content.Provider, image ocispec.Des
 	return platformSpecs, Walk(ctx, Handlers(HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
 		if desc.Platform != nil {
 			platformSpecs = append(platformSpecs, *desc.Platform)
-			return nil, SkipDesc
+			return nil, ErrSkipDesc
 		}
 
 		switch desc.MediaType {

labels/validate.go

@@ -9,15 +9,13 @@ const (
 	maxSize = 4096
 )
 
+// Validate a label's key and value are under 4096 bytes
 func Validate(k, v string) error {
-	// A label key and value should be under 4096 bytes
 	if (len(k) + len(v)) > maxSize {
 		if len(k) > 10 {
 			k = k[:10]
 		}
-
 		return errors.Wrapf(errdefs.ErrInvalidArgument, "label key and value greater than maximum size (%d bytes), key: %s", maxSize, k)
 	}
-
 	return nil
 }

linux/bundle.go

@@ -15,6 +15,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// loadBundle loads an existing bundle from disk
 func loadBundle(id, path, workdir string) *bundle {
 	return &bundle{
 		id:      id,
@@ -71,6 +72,7 @@ type bundle struct {
 
 type shimOpt func(*bundle, string, *runcopts.RuncOptions) (client.Config, client.ClientOpt)
 
+// ShimRemote is a shimOpt for connecting and starting a remote shim
 func ShimRemote(shim, daemonAddress, cgroup string, debug bool, exitHandler func()) shimOpt {
 	return func(b *bundle, ns string, ropts *runcopts.RuncOptions) (client.Config, client.ClientOpt) {
 		return b.shimConfig(ns, ropts),
@@ -78,12 +80,14 @@ func ShimRemote(shim, daemonAddress, cgroup string, debug bool, exitHandler func
 	}
 }
 
+// ShimLocal is a shimOpt for using an in process shim implementation
 func ShimLocal(exchange *events.Exchange) shimOpt {
 	return func(b *bundle, ns string, ropts *runcopts.RuncOptions) (client.Config, client.ClientOpt) {
 		return b.shimConfig(ns, ropts), client.WithLocal(exchange)
 	}
 }
 
+// ShimConnect is a shimOpt for connecting to an existing remote shim
 func ShimConnect() shimOpt {
 	return func(b *bundle, ns string, ropts *runcopts.RuncOptions) (client.Config, client.ClientOpt) {
 		return b.shimConfig(ns, ropts), client.WithConnect(b.shimAddress(ns))

linux/process.go

@@ -11,15 +11,20 @@ import (
 	"github.com/containerd/containerd/runtime"
 )
 
+// Process implements a linux process
 type Process struct {
 	id string
 	t  *Task
 }
 
+// ID of the process
 func (p *Process) ID() string {
 	return p.id
 }
 
+// Kill sends the provided signal to the underlying process
+//
+// Unable to kill all processes in the task using this method on a process
 func (p *Process) Kill(ctx context.Context, signal uint32, _ bool) error {
 	_, err := p.t.shim.Kill(ctx, &shim.KillRequest{
 		Signal: signal,
@@ -31,6 +36,7 @@ func (p *Process) Kill(ctx context.Context, signal uint32, _ bool) error {
 	return err
 }
 
+// State of process
 func (p *Process) State(ctx context.Context) (runtime.State, error) {
 	// use the container status for the status of the process
 	response, err := p.t.shim.State(ctx, &shim.StateRequest{
@@ -63,6 +69,7 @@ func (p *Process) State(ctx context.Context) (runtime.State, error) {
 	}, nil
 }
 
+// ResizePty changes the side of the process's PTY to the provided width and height
 func (p *Process) ResizePty(ctx context.Context, size runtime.ConsoleSize) error {
 	_, err := p.t.shim.ResizePty(ctx, &shim.ResizePtyRequest{
 		ID:     p.id,
@@ -75,6 +82,7 @@ func (p *Process) ResizePty(ctx context.Context, size runtime.ConsoleSize) error
 	return err
 }
 
+// CloseIO closes the provided IO pipe for the process
 func (p *Process) CloseIO(ctx context.Context) error {
 	_, err := p.t.shim.CloseIO(ctx, &shim.CloseIORequest{
 		ID:    p.id,
@@ -86,6 +94,7 @@ func (p *Process) CloseIO(ctx context.Context) error {
 	return nil
 }
 
+// Start the process
 func (p *Process) Start(ctx context.Context) error {
 	_, err := p.t.shim.Start(ctx, &shim.StartRequest{
 		ID: p.id,
@@ -96,6 +105,7 @@ func (p *Process) Start(ctx context.Context) error {
 	return nil
 }
 
+// Wait on the process to exit and return the exit status and timestamp
 func (p *Process) Wait(ctx context.Context) (*runtime.Exit, error) {
 	r, err := p.t.shim.Wait(ctx, &shim.WaitRequest{
 		ID: p.id,

linux/runtime.go

@@ -52,7 +52,7 @@ func init() {
 		Type: plugin.RuntimePlugin,
 		ID:   "linux",
 		Init: New,
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.TaskMonitorPlugin,
 			plugin.MetadataPlugin,
 		},
@@ -65,6 +65,7 @@ func init() {
 
 var _ = (runtime.Runtime)(&Runtime{})
 
+// Config options for the runtime
 type Config struct {
 	// Shim is a path or name of binary implementing the Shim GRPC API
 	Shim string `toml:"shim"`
@@ -78,6 +79,7 @@ type Config struct {
 	ShimDebug bool `toml:"shim_debug"`
 }
 
+// New returns a configured runtime
 func New(ic *plugin.InitContext) (interface{}, error) {
 	if err := os.MkdirAll(ic.Root, 0711); err != nil {
 		return nil, err
@@ -117,6 +119,7 @@ func New(ic *plugin.InitContext) (interface{}, error) {
 	return r, nil
 }
 
+// Runtime for a linux based system
 type Runtime struct {
 	root    string
 	state   string
@@ -130,10 +133,12 @@ type Runtime struct {
 	config *Config
 }
 
+// ID of the runtime
 func (r *Runtime) ID() string {
 	return pluginID
 }
 
+// Create a new task
 func (r *Runtime) Create(ctx context.Context, id string, opts runtime.CreateOpts) (_ runtime.Task, err error) {
 	namespace, err := namespaces.NamespaceRequired(ctx)
 	if err != nil {
@@ -265,6 +270,7 @@ func (r *Runtime) Create(ctx context.Context, id string, opts runtime.CreateOpts
 	return t, nil
 }
 
+// Delete a task removing all on disk state
 func (r *Runtime) Delete(ctx context.Context, c runtime.Task) (*runtime.Exit, error) {
 	namespace, err := namespaces.NamespaceRequired(ctx)
 	if err != nil {
@@ -305,6 +311,7 @@ func (r *Runtime) Delete(ctx context.Context, c runtime.Task) (*runtime.Exit, er
 	}, nil
 }
 
+// Tasks returns all tasks known to the runtime
 func (r *Runtime) Tasks(ctx context.Context) ([]runtime.Task, error) {
 	return r.tasks.GetAll(ctx)
 }
@@ -330,6 +337,7 @@ func (r *Runtime) restoreTasks(ctx context.Context) ([]*Task, error) {
 	return o, nil
 }
 
+// Get a specific task by task id
 func (r *Runtime) Get(ctx context.Context, id string) (runtime.Task, error) {
 	return r.tasks.Get(ctx, id)
 }
@@ -491,6 +499,5 @@ func (r *Runtime) getRuncOptions(ctx context.Context, id string) (*runcopts.Runc
 
 		return ropts, nil
 	}
-
 	return nil, nil
 }

linux/shim/client.go

@@ -27,6 +27,7 @@ import (
 	"google.golang.org/grpc"
 )
 
+// ClientOpt is an option for a shim client configuration
 type ClientOpt func(context.Context, Config) (shim.ShimClient, io.Closer, error)
 
 // WithStart executes a new shim process
@@ -180,6 +181,7 @@ func WithLocal(publisher events.Publisher) func(context.Context, Config) (shim.S
 	}
 }
 
+// Config contains shim specific configuration
 type Config struct {
 	Path          string
 	Namespace     string
@@ -202,6 +204,7 @@ func New(ctx context.Context, config Config, opt ClientOpt) (*Client, error) {
 	}, nil
 }
 
+// Client is a shim client containing the connection to a shim
 type Client struct {
 	shim.ShimClient
 
@@ -233,6 +236,7 @@ func (c *Client) KillShim(ctx context.Context) error {
 	return c.signalShim(ctx, unix.SIGKILL)
 }
 
+// Close the cient connection
 func (c *Client) Close() error {
 	if c.c == nil {
 		return nil

linux/shim/init.go

@@ -27,6 +27,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// InitPidFile name of the file that contains the init pid
 const InitPidFile = "init.pid"
 
 type initProcess struct {

linux/shim/service.go

@@ -29,6 +29,7 @@ import (
 
 var empty = &google_protobuf.Empty{}
 
+// RuncRoot is the path to the root runc state directory
 const RuncRoot = "/run/containerd/runc"
 
 // NewService returns a new shim service that can be used via GRPC
@@ -65,6 +66,7 @@ type platform interface {
 	close() error
 }
 
+// Service is the shim implementation of a remote shim over GRPC
 type Service struct {
 	mu sync.Mutex
 
@@ -80,6 +82,7 @@ type Service struct {
 	bundle string
 }
 
+// Create a new initial process and container with the underlying OCI runtime
 func (s *Service) Create(ctx context.Context, r *shimapi.CreateTaskRequest) (*shimapi.CreateTaskResponse, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -110,6 +113,7 @@ func (s *Service) Create(ctx context.Context, r *shimapi.CreateTaskRequest) (*sh
 	}, nil
 }
 
+// Start a process
 func (s *Service) Start(ctx context.Context, r *shimapi.StartRequest) (*shimapi.StartResponse, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -139,6 +143,7 @@ func (s *Service) Start(ctx context.Context, r *shimapi.StartRequest) (*shimapi.
 	}, nil
 }
 
+// Delete the initial process and container
 func (s *Service) Delete(ctx context.Context, r *google_protobuf.Empty) (*shimapi.DeleteResponse, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -165,6 +170,7 @@ func (s *Service) Delete(ctx context.Context, r *google_protobuf.Empty) (*shimap
 	}, nil
 }
 
+// DeleteProcess deletes an exec'd process
 func (s *Service) DeleteProcess(ctx context.Context, r *shimapi.DeleteProcessRequest) (*shimapi.DeleteResponse, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -186,6 +192,7 @@ func (s *Service) DeleteProcess(ctx context.Context, r *shimapi.DeleteProcessReq
 	}, nil
 }
 
+// Exec an additional process inside the container
 func (s *Service) Exec(ctx context.Context, r *shimapi.ExecProcessRequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -212,6 +219,7 @@ func (s *Service) Exec(ctx context.Context, r *shimapi.ExecProcessRequest) (*goo
 	return empty, nil
 }
 
+// ResizePty of a process
 func (s *Service) ResizePty(ctx context.Context, r *shimapi.ResizePtyRequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -232,6 +240,7 @@ func (s *Service) ResizePty(ctx context.Context, r *shimapi.ResizePtyRequest) (*
 	return empty, nil
 }
 
+// State returns runtime state information for a process
 func (s *Service) State(ctx context.Context, r *shimapi.StateRequest) (*shimapi.StateResponse, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -271,6 +280,7 @@ func (s *Service) State(ctx context.Context, r *shimapi.StateRequest) (*shimapi.
 	}, nil
 }
 
+// Pause the container
 func (s *Service) Pause(ctx context.Context, r *google_protobuf.Empty) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -287,6 +297,7 @@ func (s *Service) Pause(ctx context.Context, r *google_protobuf.Empty) (*google_
 	return empty, nil
 }
 
+// Resume the container
 func (s *Service) Resume(ctx context.Context, r *google_protobuf.Empty) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -303,6 +314,7 @@ func (s *Service) Resume(ctx context.Context, r *google_protobuf.Empty) (*google
 	return empty, nil
 }
 
+// Kill a process with the provided signal
 func (s *Service) Kill(ctx context.Context, r *shimapi.KillRequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -327,6 +339,7 @@ func (s *Service) Kill(ctx context.Context, r *shimapi.KillRequest) (*google_pro
 	return empty, nil
 }
 
+// ListPids returns all pids inside the container
 func (s *Service) ListPids(ctx context.Context, r *shimapi.ListPidsRequest) (*shimapi.ListPidsResponse, error) {
 	pids, err := s.getContainerPids(ctx, r.ID)
 	if err != nil {
@@ -337,6 +350,7 @@ func (s *Service) ListPids(ctx context.Context, r *shimapi.ListPidsRequest) (*sh
 	}, nil
 }
 
+// CloseIO of a process
 func (s *Service) CloseIO(ctx context.Context, r *shimapi.CloseIORequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -352,6 +366,7 @@ func (s *Service) CloseIO(ctx context.Context, r *shimapi.CloseIORequest) (*goog
 	return empty, nil
 }
 
+// Checkpoint the container
 func (s *Service) Checkpoint(ctx context.Context, r *shimapi.CheckpointTaskRequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -368,12 +383,14 @@ func (s *Service) Checkpoint(ctx context.Context, r *shimapi.CheckpointTaskReque
 	return empty, nil
 }
 
+// ShimInfo returns shim information such as the shim's pid
 func (s *Service) ShimInfo(ctx context.Context, r *google_protobuf.Empty) (*shimapi.ShimInfoResponse, error) {
 	return &shimapi.ShimInfoResponse{
 		ShimPid: uint32(os.Getpid()),
 	}, nil
 }
 
+// Update a running container
 func (s *Service) Update(ctx context.Context, r *shimapi.UpdateTaskRequest) (*google_protobuf.Empty, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -387,6 +404,7 @@ func (s *Service) Update(ctx context.Context, r *shimapi.UpdateTaskRequest) (*go
 	return empty, nil
 }
 
+// Wait for a process to exit
 func (s *Service) Wait(ctx context.Context, r *shimapi.WaitRequest) (*shimapi.WaitResponse, error) {
 	s.mu.Lock()
 	p := s.processes[r.ID]

linux/task.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gogo/protobuf/types"
 )
 
+// Task on a linux based system
 type Task struct {
 	id        string
 	pid       int
@@ -45,10 +46,12 @@ func newTask(id, namespace string, pid int, shim *client.Client, monitor runtime
 	}, nil
 }
 
+// ID of the task
 func (t *Task) ID() string {
 	return t.id
 }
 
+// Info returns task information about the runtime and namespace
 func (t *Task) Info() runtime.TaskInfo {
 	return runtime.TaskInfo{
 		ID:        t.id,
@@ -57,6 +60,7 @@ func (t *Task) Info() runtime.TaskInfo {
 	}
 }
 
+// Start the task
 func (t *Task) Start(ctx context.Context) error {
 	hasCgroup := t.cg != nil
 	r, err := t.shim.Start(ctx, &shim.StartRequest{
@@ -79,6 +83,7 @@ func (t *Task) Start(ctx context.Context) error {
 	return nil
 }
 
+// State returns runtime information for the task
 func (t *Task) State(ctx context.Context) (runtime.State, error) {
 	response, err := t.shim.State(ctx, &shim.StateRequest{
 		ID: t.id,
@@ -114,6 +119,7 @@ func (t *Task) State(ctx context.Context) (runtime.State, error) {
 	}, nil
 }
 
+// Pause the task and all processes
 func (t *Task) Pause(ctx context.Context) error {
 	_, err := t.shim.Pause(ctx, empty)
 	if err != nil {
@@ -122,6 +128,7 @@ func (t *Task) Pause(ctx context.Context) error {
 	return err
 }
 
+// Resume the task and all processes
 func (t *Task) Resume(ctx context.Context) error {
 	if _, err := t.shim.Resume(ctx, empty); err != nil {
 		return errdefs.FromGRPC(err)
@@ -129,6 +136,9 @@ func (t *Task) Resume(ctx context.Context) error {
 	return nil
 }
 
+// Kill the task using the provided signal
+//
+// Optionally send the signal to all processes that are a child of the task
 func (t *Task) Kill(ctx context.Context, signal uint32, all bool) error {
 	if _, err := t.shim.Kill(ctx, &shim.KillRequest{
 		ID:     t.id,
@@ -140,6 +150,7 @@ func (t *Task) Kill(ctx context.Context, signal uint32, all bool) error {
 	return nil
 }
 
+// Exec creates a new process inside the task
 func (t *Task) Exec(ctx context.Context, id string, opts runtime.ExecOpts) (runtime.Process, error) {
 	request := &shim.ExecProcessRequest{
 		ID:       id,
@@ -158,6 +169,7 @@ func (t *Task) Exec(ctx context.Context, id string, opts runtime.ExecOpts) (runt
 	}, nil
 }
 
+// Pids returns all system level process ids running inside the task
 func (t *Task) Pids(ctx context.Context) ([]uint32, error) {
 	resp, err := t.shim.ListPids(ctx, &shim.ListPidsRequest{
 		ID: t.id,
@@ -168,6 +180,7 @@ func (t *Task) Pids(ctx context.Context) ([]uint32, error) {
 	return resp.Pids, nil
 }
 
+// ResizePty changes the side of the task's PTY to the provided width and height
 func (t *Task) ResizePty(ctx context.Context, size runtime.ConsoleSize) error {
 	_, err := t.shim.ResizePty(ctx, &shim.ResizePtyRequest{
 		ID:     t.id,
@@ -180,6 +193,7 @@ func (t *Task) ResizePty(ctx context.Context, size runtime.ConsoleSize) error {
 	return err
 }
 
+// CloseIO closes the provided IO on the task
 func (t *Task) CloseIO(ctx context.Context) error {
 	_, err := t.shim.CloseIO(ctx, &shim.CloseIORequest{
 		ID:    t.id,
@@ -191,6 +205,7 @@ func (t *Task) CloseIO(ctx context.Context) error {
 	return err
 }
 
+// Checkpoint creates a system level dump of the task and process information that can be later restored
 func (t *Task) Checkpoint(ctx context.Context, path string, options *types.Any) error {
 	r := &shim.CheckpointTaskRequest{
 		Path:    path,
@@ -202,6 +217,7 @@ func (t *Task) Checkpoint(ctx context.Context, path string, options *types.Any)
 	return nil
 }
 
+// DeleteProcess removes the provided process from the task and deletes all on disk state
 func (t *Task) DeleteProcess(ctx context.Context, id string) (*runtime.Exit, error) {
 	r, err := t.shim.DeleteProcess(ctx, &shim.DeleteProcessRequest{
 		ID: id,
@@ -216,6 +232,7 @@ func (t *Task) DeleteProcess(ctx context.Context, id string) (*runtime.Exit, err
 	}, nil
 }
 
+// Update changes runtime information of a running task
 func (t *Task) Update(ctx context.Context, resources *types.Any) error {
 	if _, err := t.shim.Update(ctx, &shim.UpdateTaskRequest{
 		Resources: resources,
@@ -225,6 +242,7 @@ func (t *Task) Update(ctx context.Context, resources *types.Any) error {
 	return nil
 }
 
+// Process returns a specific process inside the task by the process id
 func (t *Task) Process(ctx context.Context, id string) (runtime.Process, error) {
 	// TODO: verify process exists for container
 	return &Process{
@@ -233,6 +251,7 @@ func (t *Task) Process(ctx context.Context, id string) (runtime.Process, error)
 	}, nil
 }
 
+// Metrics returns runtime specific system level metric information for the task
 func (t *Task) Metrics(ctx context.Context) (interface{}, error) {
 	stats, err := t.cg.Stat(cgroups.IgnoreNotExist)
 	if err != nil {
@@ -241,10 +260,12 @@ func (t *Task) Metrics(ctx context.Context) (interface{}, error) {
 	return stats, nil
 }
 
+// Cgroup returns the underlying cgroup for a linux task
 func (t *Task) Cgroup() cgroups.Cgroup {
 	return t.cg
 }
 
+// Wait for the task to exit returning the status and timestamp
 func (t *Task) Wait(ctx context.Context) (*runtime.Exit, error) {
 	r, err := t.shim.Wait(ctx, &shim.WaitRequest{
 		ID: t.id,

metadata/containers.go

@@ -22,6 +22,7 @@ type containerStore struct {
 	tx *bolt.Tx
 }
 
+// NewContainerStore returns a Store backed by an underlying bolt DB
 func NewContainerStore(tx *bolt.Tx) containers.Store {
 	return &containerStore{
 		tx: tx,

metadata/content.go

@@ -417,11 +417,7 @@ func (nw *namespacedWriter) commit(ctx context.Context, tx *bolt.Tx, size int64,
 	if err := boltutil.WriteLabels(bkt, base.Labels); err != nil {
 		return err
 	}
-	if err := bkt.Put(bucketKeySize, sizeEncoded); err != nil {
+	return bkt.Put(bucketKeySize, sizeEncoded)
-		return err
-	}
-
-	return nil
 }
 
 func (nw *namespacedWriter) Status() (content.Status, error) {
@@ -497,9 +493,5 @@ func writeInfo(info *content.Info, bkt *bolt.Bucket) error {
 		return err
 	}
 
-	if err := bkt.Put(bucketKeySize, sizeEncoded); err != nil {
+	return bkt.Put(bucketKeySize, sizeEncoded)
-		return err
-	}
-
-	return nil
 }

metadata/images.go

@@ -22,6 +22,7 @@ type imageStore struct {
 	tx *bolt.Tx
 }
 
+// NewImageStore returns a store backed by a bolt DB
 func NewImageStore(tx *bolt.Tx) images.Store {
 	return &imageStore{tx: tx}
 }
@@ -281,7 +282,7 @@ func writeImage(bkt *bolt.Bucket, image *images.Image) error {
 func encodeSize(size int64) ([]byte, error) {
 	var (
 		buf         [binary.MaxVarintLen64]byte
-		sizeEncoded []byte = buf[:]
+		sizeEncoded = buf[:]
 	)
 	sizeEncoded = sizeEncoded[:binary.PutVarint(sizeEncoded, size)]
 

metadata/namespaces.go

@@ -14,6 +14,7 @@ type namespaceStore struct {
 	tx *bolt.Tx
 }
 
+// NewNamespaceStore returns a store backed by a bolt DB
 func NewNamespaceStore(tx *bolt.Tx) namespaces.Store {
 	return &namespaceStore{tx: tx}
 }

metrics/cgroups/cgroups.go

@@ -15,6 +15,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Config for the cgroups monitor
 type Config struct {
 	NoPrometheus bool `toml:"no_prometheus"`
 }
@@ -28,14 +29,15 @@ func init() {
 	})
 }
 
+// New returns a new cgroups monitor
 func New(ic *plugin.InitContext) (interface{}, error) {
 	var ns *metrics.Namespace
 	config := ic.Config.(*Config)
 	if !config.NoPrometheus {
 		ns = metrics.NewNamespace("container", "", nil)
 	}
-	collector := NewCollector(ns)
+	collector := newCollector(ns)
-	oom, err := NewOOMCollector(ns)
+	oom, err := newOOMCollector(ns)
 	if err != nil {
 		return nil, err
 	}
@@ -51,8 +53,8 @@ func New(ic *plugin.InitContext) (interface{}, error) {
 }
 
 type cgroupsMonitor struct {
-	collector *Collector
+	collector *collector
-	oom       *OOMCollector
+	oom       *oomCollector
 	context   context.Context
 	publisher events.Publisher
 }

metrics/cgroups/metrics.go

@@ -14,22 +14,24 @@ import (
 )
 
 var (
+	// ErrAlreadyCollected is returned when a cgroups is already being monitored
 	ErrAlreadyCollected = errors.New("cgroup is already being collected")
-	ErrCgroupNotExists  = errors.New("cgroup does not exist in the collector")
+	// ErrCgroupNotExists is returns when a cgroup no longer exists
+	ErrCgroupNotExists = errors.New("cgroup does not exist in the collector")
 )
 
 // Trigger will be called when an event happens and provides the cgroup
 // where the event originated from
 type Trigger func(string, string, cgroups.Cgroup)
 
-// New registers the Collector with the provided namespace and returns it so
+// newCollector registers the collector with the provided namespace and returns it so
 // that cgroups can be added for collection
-func NewCollector(ns *metrics.Namespace) *Collector {
+func newCollector(ns *metrics.Namespace) *collector {
 	if ns == nil {
-		return &Collector{}
+		return &collector{}
 	}
 	// add machine cpus and memory info
-	c := &Collector{
+	c := &collector{
 		ns:      ns,
 		cgroups: make(map[string]*task),
 	}
@@ -52,9 +54,9 @@ func taskID(id, namespace string) string {
 	return fmt.Sprintf("%s-%s", id, namespace)
 }
 
-// Collector provides the ability to collect container stats and export
+// collector provides the ability to collect container stats and export
 // them in the prometheus format
-type Collector struct {
+type collector struct {
 	mu sync.RWMutex
 
 	cgroups map[string]*task
@@ -62,13 +64,13 @@ type Collector struct {
 	metrics []*metric
 }
 
-func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+func (c *collector) Describe(ch chan<- *prometheus.Desc) {
 	for _, m := range c.metrics {
 		ch <- m.desc(c.ns)
 	}
 }
 
-func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+func (c *collector) Collect(ch chan<- prometheus.Metric) {
 	c.mu.RLock()
 	wg := &sync.WaitGroup{}
 	for _, t := range c.cgroups {
@@ -79,7 +81,7 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric) {
 	wg.Wait()
 }
 
-func (c *Collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) {
+func (c *collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) {
 	defer wg.Done()
 	stats, err := cg.Stat(cgroups.IgnoreNotExist)
 	if err != nil {
@@ -92,7 +94,7 @@ func (c *Collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- p
 }
 
 // Add adds the provided cgroup and id so that metrics are collected and exported
-func (c *Collector) Add(id, namespace string, cg cgroups.Cgroup) error {
+func (c *collector) Add(id, namespace string, cg cgroups.Cgroup) error {
 	if c.ns == nil {
 		return nil
 	}
@@ -110,7 +112,7 @@ func (c *Collector) Add(id, namespace string, cg cgroups.Cgroup) error {
 }
 
 // Remove removes the provided cgroup by id from the collector
-func (c *Collector) Remove(id, namespace string) {
+func (c *collector) Remove(id, namespace string) {
 	if c.ns == nil {
 		return
 	}

metrics/cgroups/oom.go

@@ -14,7 +14,7 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
+func newOOMCollector(ns *metrics.Namespace) (*oomCollector, error) {
 	fd, err := unix.EpollCreate1(unix.EPOLL_CLOEXEC)
 	if err != nil {
 		return nil, err
@@ -23,7 +23,7 @@ func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
 	if ns != nil {
 		desc = ns.NewDesc("memory_oom", "The number of times a container has received an oom event", metrics.Total, "container_id", "namespace")
 	}
-	c := &OOMCollector{
+	c := &oomCollector{
 		fd:   fd,
 		desc: desc,
 		set:  make(map[uintptr]*oom),
@@ -35,7 +35,7 @@ func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
 	return c, nil
 }
 
-type OOMCollector struct {
+type oomCollector struct {
 	mu sync.Mutex
 
 	desc *prometheus.Desc
@@ -51,7 +51,7 @@ type oom struct {
 	count     int64
 }
 
-func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...Trigger) error {
+func (o *oomCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...Trigger) error {
 	o.mu.Lock()
 	defer o.mu.Unlock()
 	fd, err := cg.OOMEventFD()
@@ -71,11 +71,11 @@ func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...
 	return unix.EpollCtl(o.fd, unix.EPOLL_CTL_ADD, int(fd), &event)
 }
 
-func (o *OOMCollector) Describe(ch chan<- *prometheus.Desc) {
+func (o *oomCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- o.desc
 }
 
-func (o *OOMCollector) Collect(ch chan<- prometheus.Metric) {
+func (o *oomCollector) Collect(ch chan<- prometheus.Metric) {
 	o.mu.Lock()
 	defer o.mu.Unlock()
 	for _, t := range o.set {
@@ -85,11 +85,11 @@ func (o *OOMCollector) Collect(ch chan<- prometheus.Metric) {
 }
 
 // Close closes the epoll fd
-func (o *OOMCollector) Close() error {
+func (o *oomCollector) Close() error {
 	return unix.Close(int(o.fd))
 }
 
-func (o *OOMCollector) start() {
+func (o *oomCollector) start() {
 	var events [128]unix.EpollEvent
 	for {
 		n, err := unix.EpollWait(o.fd, events[:], -1)
@@ -105,7 +105,7 @@ func (o *OOMCollector) start() {
 	}
 }
 
-func (o *OOMCollector) process(fd uintptr, event uint32) {
+func (o *oomCollector) process(fd uintptr, event uint32) {
 	// make sure to always flush the fd
 	flush(fd)
 

mount/mount.go

@@ -13,8 +13,8 @@ type Mount struct {
 	Options []string
 }
 
-// MountAll mounts all the provided mounts to the provided target
+// All mounts all the provided mounts to the provided target
-func MountAll(mounts []Mount, target string) error {
+func All(mounts []Mount, target string) error {
 	for _, m := range mounts {
 		if err := m.Mount(target); err != nil {
 			return err

mount/mount_linux.go

@@ -6,6 +6,7 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+// Mount to the provided target path
 func (m *Mount) Mount(target string) error {
 	flags, data := parseMountOptions(m.Options)
 
@@ -40,6 +41,7 @@ func (m *Mount) Mount(target string) error {
 	return nil
 }
 
+// Unmount the provided mount path with the flags
 func Unmount(mount string, flags int) error {
 	return unix.Unmount(mount, flags)
 }

namespaces/context.go

@@ -9,8 +9,10 @@ import (
 )
 
 const (
+	// NamespaceEnvVar is the environment variable key name
 	NamespaceEnvVar = "CONTAINERD_NAMESPACE"
-	Default         = "default"
+	// Default is the name of the default namespace
+	Default = "default"
 )
 
 type namespaceKey struct{}

plugin/context.go

@@ -9,7 +9,8 @@ import (
 	"github.com/containerd/containerd/log"
 )
 
-func NewContext(ctx context.Context, plugins map[PluginType]map[string]interface{}, root, state, id string) *InitContext {
+// NewContext returns a new plugin InitContext
+func NewContext(ctx context.Context, plugins map[Type]map[string]interface{}, root, state, id string) *InitContext {
 	return &InitContext{
 		plugins: plugins,
 		Root:    filepath.Join(root, id),
@@ -18,6 +19,7 @@ func NewContext(ctx context.Context, plugins map[PluginType]map[string]interface
 	}
 }
 
+// InitContext is used for plugin inititalization
 type InitContext struct {
 	Root    string
 	State   string
@@ -26,17 +28,19 @@ type InitContext struct {
 	Config  interface{}
 	Events  *events.Exchange
 
-	plugins map[PluginType]map[string]interface{}
+	plugins map[Type]map[string]interface{}
 }
 
-func (i *InitContext) Get(t PluginType) (interface{}, error) {
+// Get returns the first plugin by its type
+func (i *InitContext) Get(t Type) (interface{}, error) {
 	for _, v := range i.plugins[t] {
 		return v, nil
 	}
 	return nil, fmt.Errorf("no plugins registered for %s", t)
 }
 
-func (i *InitContext) GetAll(t PluginType) (map[string]interface{}, error) {
+// GetAll returns all plugins with the specific type
+func (i *InitContext) GetAll(t Type) (map[string]interface{}, error) {
 	p, ok := i.plugins[t]
 	if !ok {
 		return nil, fmt.Errorf("no plugins registered for %s", t)

plugin/differ.go

@@ -6,6 +6,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Differ allows the apply and creation of filesystem diffs between mounts
 type Differ interface {
 	Apply(ctx context.Context, desc ocispec.Descriptor, mount []mount.Mount) (ocispec.Descriptor, error)
 	DiffMounts(ctx context.Context, lower, upper []mount.Mount, media, ref string) (ocispec.Descriptor, error)

plugin/plugin.go

@@ -9,49 +9,62 @@ import (
 )
 
 var (
-	ErrNoPluginType = errors.New("plugin: no type")
+	// ErrNoType is returned when no type is specified
-	ErrNoPluginID   = errors.New("plugin: no id")
+	ErrNoType = errors.New("plugin: no type")
+	// ErrNoPluginID is returned when no id is specified
+	ErrNoPluginID = errors.New("plugin: no id")
 
-	// SkipPlugin is used when a plugin is not initialized and should not be loaded,
+	// ErrSkipPlugin is used when a plugin is not initialized and should not be loaded,
 	// this allows the plugin loader differentiate between a plugin which is configured
 	// not to load and one that fails to load.
-	SkipPlugin = errors.New("skip plugin")
+	ErrSkipPlugin = errors.New("skip plugin")
 )
 
 // IsSkipPlugin returns true if the error is skipping the plugin
 func IsSkipPlugin(err error) bool {
-	if errors.Cause(err) == SkipPlugin {
+	if errors.Cause(err) == ErrSkipPlugin {
 		return true
 	}
 	return false
 }
 
-type PluginType string
+// Type is the type of the plugin
+type Type string
 
 const (
-	RuntimePlugin     PluginType = "io.containerd.runtime.v1"
+	// RuntimePlugin implements a runtime
-	GRPCPlugin        PluginType = "io.containerd.grpc.v1"
+	RuntimePlugin Type = "io.containerd.runtime.v1"
-	SnapshotPlugin    PluginType = "io.containerd.snapshotter.v1"
+	// GRPCPlugin implements a grpc service
-	TaskMonitorPlugin PluginType = "io.containerd.monitor.v1"
+	GRPCPlugin Type = "io.containerd.grpc.v1"
-	DiffPlugin        PluginType = "io.containerd.differ.v1"
+	// SnapshotPlugin implements a snapshotter
-	MetadataPlugin    PluginType = "io.containerd.metadata.v1"
+	SnapshotPlugin Type = "io.containerd.snapshotter.v1"
-	ContentPlugin     PluginType = "io.containerd.content.v1"
+	// TaskMonitorPlugin implements a task monitor
+	TaskMonitorPlugin Type = "io.containerd.monitor.v1"
+	// DiffPlugin implements a differ
+	DiffPlugin Type = "io.containerd.differ.v1"
+	// MetadataPlugin implements a metadata store
+	MetadataPlugin Type = "io.containerd.metadata.v1"
+	// ContentPlugin implements a content store
+	ContentPlugin Type = "io.containerd.content.v1"
 )
 
+// Registration contains information for registering a plugin
 type Registration struct {
-	Type     PluginType
+	Type     Type
 	ID       string
 	Config   interface{}
-	Requires []PluginType
+	Requires []Type
 	Init     func(*InitContext) (interface{}, error)
 
 	added bool
 }
 
+// URI returns the full plugin URI
 func (r *Registration) URI() string {
 	return fmt.Sprintf("%s.%s", r.Type, r.ID)
 }
 
+// Service allows GRPC services to be registered with the underlying server
 type Service interface {
 	Register(*grpc.Server) error
 }
@@ -75,11 +88,12 @@ func Load(path string) (err error) {
 	return loadPlugins(path)
 }
 
+// Register allows plugins to register
 func Register(r *Registration) {
 	register.Lock()
 	defer register.Unlock()
 	if r.Type == "" {
-		panic(ErrNoPluginType)
+		panic(ErrNoType)
 	}
 	if r.ID == "" {
 		panic(ErrNoPluginID)
@@ -87,6 +101,7 @@ func Register(r *Registration) {
 	register.r = append(register.r, r)
 }
 
+// Graph returns an ordered list of registered plugins for initialization
 func Graph() (ordered []*Registration) {
 	for _, r := range register.r {
 		children(r.Requires, &ordered)
@@ -98,7 +113,7 @@ func Graph() (ordered []*Registration) {
 	return ordered
 }
 
-func children(types []PluginType, ordered *[]*Registration) {
+func children(types []Type, ordered *[]*Registration) {
 	for _, t := range types {
 		for _, r := range register.r {
 			if r.Type == t {

progress/bar.go

@@ -16,6 +16,7 @@ type Bar float64
 
 var _ fmt.Formatter = Bar(1.0)
 
+// Format the progress bar as output
 func (h Bar) Format(state fmt.State, r rune) {
 	switch r {
 	case 'r':

progress/humaans.go

@@ -10,16 +10,20 @@ import (
 // Bytes converts a regular int64 to human readable type.
 type Bytes int64
 
+// String returns the string representation of bytes
 func (b Bytes) String() string {
 	return units.CustomSize("%02.1f %s", float64(b), 1024.0, []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"})
 }
 
+// BytesPerSecond is the rate in seconds for byte operations
 type BytesPerSecond int64
 
+// NewBytesPerSecond returns the rate that n bytes were written in the provided duration
 func NewBytesPerSecond(n int64, duration time.Duration) BytesPerSecond {
 	return BytesPerSecond(float64(n) / duration.Seconds())
 }
 
+// String returns the string representation of the rate
 func (bps BytesPerSecond) String() string {
 	return fmt.Sprintf("%v/s", Bytes(bps))
 }

progress/writer.go

@@ -16,12 +16,14 @@ type Writer struct {
 	lines int
 }
 
+// NewWriter returns a writer
 func NewWriter(w io.Writer) *Writer {
 	return &Writer{
 		w: w,
 	}
 }
 
+// Write the provided bytes
 func (w *Writer) Write(p []byte) (n int, err error) {
 	return w.buf.Write(p)
 }

protobuf/plugin/helpers.go

@@ -5,6 +5,7 @@ import (
 	"github.com/gogo/protobuf/protoc-gen-gogo/descriptor"
 )
 
+// FieldpathEnabled returns true if E_Fieldpath is enabled
 func FieldpathEnabled(file *descriptor.FileDescriptorProto, message *descriptor.DescriptorProto) bool {
 	return proto.GetBoolExtension(message.Options, E_Fieldpath, proto.GetBoolExtension(file.Options, E_FieldpathAll, false))
 }

reaper/reaper.go

@@ -12,6 +12,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// ErrNoSuchProcess is returned when the process no longer exists
 var ErrNoSuchProcess = errors.New("no such process")
 
 const bufferSize = 2048
@@ -36,10 +37,12 @@ func Reap() error {
 	return err
 }
 
+// Default is the default monitor initialized for the package
 var Default = &Monitor{
 	subscribers: make(map[chan runc.Exit]struct{}),
 }
 
+// Monitor monitors the underlying system for process status changes
 type Monitor struct {
 	sync.Mutex
 
@@ -73,6 +76,7 @@ func (m *Monitor) Wait(c *exec.Cmd, ec chan runc.Exit) (int, error) {
 	return -1, ErrNoSuchProcess
 }
 
+// Subscribe to process exit changes
 func (m *Monitor) Subscribe() chan runc.Exit {
 	c := make(chan runc.Exit, bufferSize)
 	m.Lock()
@@ -81,6 +85,7 @@ func (m *Monitor) Subscribe() chan runc.Exit {
 	return c
 }
 
+// Unsubscribe to process exit changes
 func (m *Monitor) Unsubscribe(c chan runc.Exit) {
 	m.Lock()
 	delete(m.subscribers, c)

reference/reference.go

@@ -12,8 +12,11 @@ import (
 )
 
 var (
-	ErrInvalid          = errors.New("invalid reference")
+	// ErrInvalid is returned when there is an invalid reference
-	ErrObjectRequired   = errors.New("object required")
+	ErrInvalid = errors.New("invalid reference")
+	// ErrObjectRequired is returned when the object is required
+	ErrObjectRequired = errors.New("object required")
+	// ErrHostnameRequired is returned when the hostname is required
 	ErrHostnameRequired = errors.New("hostname required")
 )
 
@@ -138,7 +141,6 @@ func SplitObject(obj string) (tag string, dgst digest.Digest) {
 	parts := strings.SplitAfterN(obj, "@", 2)
 	if len(parts) < 2 {
 		return parts[0], ""
-	} else {
-		return parts[0], digest.Digest(parts[1])
 	}
+	return parts[0], digest.Digest(parts[1])
 }

remotes/docker/schema1/converter.go

@@ -47,6 +47,7 @@ type Converter struct {
 	layerBlobs map[digest.Digest]ocispec.Descriptor
 }
 
+// NewConverter returns a new converter
 func NewConverter(contentStore content.Store, fetcher remotes.Fetcher) *Converter {
 	return &Converter{
 		contentStore: contentStore,
@@ -56,6 +57,7 @@ func NewConverter(contentStore content.Store, fetcher remotes.Fetcher) *Converte
 	}
 }
 
+// Handle fetching descriptors for a docker media type
 func (c *Converter) Handle(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
 	switch desc.MediaType {
 	case images.MediaTypeDockerSchema1Manifest:
@@ -101,6 +103,7 @@ func (c *Converter) Handle(ctx context.Context, desc ocispec.Descriptor) ([]ocis
 	}
 }
 
+// Convert a docker manifest to an OCI descriptor
 func (c *Converter) Convert(ctx context.Context) (ocispec.Descriptor, error) {
 	history, diffIDs, err := c.schema1ManifestHistory()
 	if err != nil {

remotes/docker/status.go

@@ -8,6 +8,7 @@ import (
 	"github.com/pkg/errors"
 )
 
+// Status of a content operation
 type Status struct {
 	content.Status
 
@@ -15,6 +16,7 @@ type Status struct {
 	UploadUUID string
 }
 
+// StatusTracker to track status of operations
 type StatusTracker interface {
 	GetStatus(string) (Status, error)
 	SetStatus(string, Status)
@@ -25,6 +27,7 @@ type memoryStatusTracker struct {
 	m        sync.Mutex
 }
 
+// NewInMemoryTracker returns a StatusTracker that tracks content status in-memory
 func NewInMemoryTracker() StatusTracker {
 	return &memoryStatusTracker{
 		statuses: map[string]Status{},

remotes/resolver.go

@@ -32,11 +32,13 @@ type Resolver interface {
 	Pusher(ctx context.Context, ref string) (Pusher, error)
 }
 
+// Fetcher fetches content
 type Fetcher interface {
 	// Fetch the resource identified by the descriptor.
 	Fetch(ctx context.Context, desc ocispec.Descriptor) (io.ReadCloser, error)
 }
 
+// Pusher pushes content
 type Pusher interface {
 	// Push returns a content writer for the given resource identified
 	// by the descriptor.
@@ -47,6 +49,7 @@ type Pusher interface {
 // function.
 type FetcherFunc func(ctx context.Context, desc ocispec.Descriptor) (io.ReadCloser, error)
 
+// Fetch content
 func (fn FetcherFunc) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.ReadCloser, error) {
 	return fn(ctx, desc)
 }
@@ -55,6 +58,7 @@ func (fn FetcherFunc) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.Re
 // function.
 type PusherFunc func(ctx context.Context, desc ocispec.Descriptor, r io.Reader) error
 
-func (fn PusherFunc) Pusher(ctx context.Context, desc ocispec.Descriptor, r io.Reader) error {
+// Push content
+func (fn PusherFunc) Push(ctx context.Context, desc ocispec.Descriptor, r io.Reader) error {
 	return fn(ctx, desc, r)
 }

rootfs/init.go

@@ -19,11 +19,13 @@ var (
 
 type initializerFunc func(string) error
 
+// Mounter handles mount and unmount
 type Mounter interface {
 	Mount(target string, mounts ...mount.Mount) error
 	Unmount(target string) error
 }
 
+// InitRootFS initializes the snapshot for use as a rootfs
 func InitRootFS(ctx context.Context, name string, parent digest.Digest, readonly bool, snapshotter snapshot.Snapshotter, mounter Mounter) ([]mount.Mount, error) {
 	_, err := snapshotter.Stat(ctx, name)
 	if err == nil {

runtime/events.go

@@ -1,15 +1,26 @@
 package runtime
 
 const (
-	TaskCreateEventTopic       = "/tasks/create"
+	// TaskCreateEventTopic for task create
-	TaskStartEventTopic        = "/tasks/start"
+	TaskCreateEventTopic = "/tasks/create"
-	TaskOOMEventTopic          = "/tasks/oom"
+	// TaskStartEventTopic for task start
-	TaskExitEventTopic         = "/tasks/exit"
+	TaskStartEventTopic = "/tasks/start"
-	TaskDeleteEventTopic       = "/tasks/delete"
+	// TaskOOMEventTopic for task oom
-	TaskExecAddedEventTopic    = "/tasks/exec-added"
+	TaskOOMEventTopic = "/tasks/oom"
-	TaskExecStartedEventTopic  = "/tasks/exec-started"
+	// TaskExitEventTopic for task exit
-	TaskPausedEventTopic       = "/tasks/paused"
+	TaskExitEventTopic = "/tasks/exit"
-	TaskResumedEventTopic      = "/tasks/resumed"
+	// TaskDeleteEventTopic for task delete
+	TaskDeleteEventTopic = "/tasks/delete"
+	// TaskExecAddedEventTopic for task exec create
+	TaskExecAddedEventTopic = "/tasks/exec-added"
+	// TaskExecStartedEventTopic for task exec start
+	TaskExecStartedEventTopic = "/tasks/exec-started"
+	// TaskPausedEventTopic for task pause
+	TaskPausedEventTopic = "/tasks/paused"
+	// TaskResumedEventTopic for task resume
+	TaskResumedEventTopic = "/tasks/resumed"
+	// TaskCheckpointedEventTopic for task checkpoint
 	TaskCheckpointedEventTopic = "/tasks/checkpointed"
-	TaskUnknownTopic           = "/tasks/?"
+	// TaskUnknownTopic for unknown task events
+	TaskUnknownTopic = "/tasks/?"
 )

runtime/monitor.go

@@ -8,12 +8,14 @@ type TaskMonitor interface {
 	Stop(Task) error
 }
 
+// NewMultiTaskMonitor returns a new TaskMonitor broadcasting to the provided monitors
 func NewMultiTaskMonitor(monitors ...TaskMonitor) TaskMonitor {
 	return &multiTaskMonitor{
 		monitors: monitors,
 	}
 }
 
+// NewNoopMonitor is a task monitor that does nothing
 func NewNoopMonitor() TaskMonitor {
 	return &noopTaskMonitor{}
 }

runtime/runtime.go

@@ -8,6 +8,7 @@ import (
 	"github.com/gogo/protobuf/types"
 )
 
+// IO holds process IO information
 type IO struct {
 	Stdin    string
 	Stdout   string
@@ -15,6 +16,7 @@ type IO struct {
 	Terminal bool
 }
 
+// CreateOpts contains task creation data
 type CreateOpts struct {
 	// Spec is the OCI runtime spec
 	Spec *types.Any
@@ -28,6 +30,7 @@ type CreateOpts struct {
 	Options *types.Any
 }
 
+// Exit information for a process
 type Exit struct {
 	Pid       uint32
 	Status    uint32

server/server.go

@@ -63,7 +63,7 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 			rpc:    rpc,
 			events: events.NewExchange(),
 		}
-		initialized = make(map[plugin.PluginType]map[string]interface{})
+		initialized = make(map[plugin.Type]map[string]interface{})
 	)
 	for _, p := range plugins {
 		id := p.URI()

services/containers/service.go

@@ -20,7 +20,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "containers",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.MetadataPlugin,
 		},
 		Init: func(ic *plugin.InitContext) (interface{}, error) {

services/content/service.go

@@ -39,7 +39,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "content",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.ContentPlugin,
 			plugin.MetadataPlugin,
 		},

services/diff/service.go

@@ -26,7 +26,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "diff",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.DiffPlugin,
 		},
 		Config: &config{

services/images/service.go

@@ -20,7 +20,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "images",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.MetadataPlugin,
 		},
 		Init: func(ic *plugin.InitContext) (interface{}, error) {

services/namespaces/service.go

@@ -21,7 +21,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "namespaces",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.MetadataPlugin,
 		},
 		Init: func(ic *plugin.InitContext) (interface{}, error) {

services/snapshot/service.go

@@ -24,7 +24,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "snapshots",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.SnapshotPlugin,
 			plugin.MetadataPlugin,
 		},

services/tasks/service.go

@@ -41,7 +41,7 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type: plugin.GRPCPlugin,
 		ID:   "tasks",
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.RuntimePlugin,
 			plugin.MetadataPlugin,
 			plugin.ContentPlugin,

snapshot/btrfs/btrfs_test.go

@@ -108,7 +108,7 @@ func TestBtrfsMounts(t *testing.T) {
 	if err := os.MkdirAll(target, 0755); err != nil {
 		t.Fatal(err)
 	}
-	if err := mount.MountAll(mounts, target); err != nil {
+	if err := mount.All(mounts, target); err != nil {
 		t.Fatal(err)
 	}
 	defer testutil.Unmount(t, target)
@@ -138,7 +138,7 @@ func TestBtrfsMounts(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := mount.MountAll(mounts, target); err != nil {
+	if err := mount.All(mounts, target); err != nil {
 		t.Fatal(err)
 	}
 	defer testutil.Unmount(t, target)

snapshot/overlay/overlay_test.go

@@ -221,7 +221,7 @@ func TestOverlayOverlayRead(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	if err := mount.MountAll(mounts, dest); err != nil {
+	if err := mount.All(mounts, dest); err != nil {
 		t.Error(err)
 		return
 	}

snapshot/snapshotter.go

@@ -146,7 +146,7 @@ func (u *Usage) Add(other Usage) {
 // the active snapshot. Mount this to the temporary location with the
 // following:
 //
-//	if err := containerd.MountAll(mounts, tmpDir); err != nil { ... }
+//	if err := mount.All(mounts, tmpDir); err != nil { ... }
 //
 // Once the mounts are performed, our temporary location is ready to capture
 // a diff. In practice, this works similar to a filesystem transaction. The

snapshot/testsuite/helpers.go

@@ -20,7 +20,7 @@ func applyToMounts(m []mount.Mount, work string, a fstest.Applier) (err error) {
 	}
 	defer os.RemoveAll(td)
 
-	if err := mount.MountAll(m, td); err != nil {
+	if err := mount.All(m, td); err != nil {
 		return errors.Wrap(err, "failed to mount")
 	}
 	defer func() {
@@ -76,7 +76,7 @@ func checkSnapshot(ctx context.Context, sn snapshot.Snapshotter, work, name, che
 		}
 	}()
 
-	if err := mount.MountAll(m, td); err != nil {
+	if err := mount.All(m, td); err != nil {
 		return errors.Wrap(err, "failed to mount")
 	}
 	defer func() {

snapshot/testsuite/testsuite.go

@@ -119,7 +119,7 @@ func checkSnapshotterBasic(ctx context.Context, t *testing.T, snapshotter snapsh
 		t.Fatal("expected mounts to have entries")
 	}
 
-	if err := mount.MountAll(mounts, preparing); err != nil {
+	if err := mount.All(mounts, preparing); err != nil {
 		t.Fatalf("failure reason: %+v", err)
 	}
 	defer testutil.Unmount(t, preparing)
@@ -150,7 +150,7 @@ func checkSnapshotterBasic(ctx context.Context, t *testing.T, snapshotter snapsh
 	if err != nil {
 		t.Fatalf("failure reason: %+v", err)
 	}
-	if err := mount.MountAll(mounts, next); err != nil {
+	if err := mount.All(mounts, next); err != nil {
 		t.Fatalf("failure reason: %+v", err)
 	}
 	defer testutil.Unmount(t, next)
@@ -212,7 +212,7 @@ func checkSnapshotterBasic(ctx context.Context, t *testing.T, snapshotter snapsh
 	if err != nil {
 		t.Fatalf("failure reason: %+v", err)
 	}
-	if err := mount.MountAll(mounts, nextnext); err != nil {
+	if err := mount.All(mounts, nextnext); err != nil {
 		t.Fatalf("failure reason: %+v", err)
 	}
 
@@ -245,7 +245,7 @@ func checkSnapshotterStatActive(ctx context.Context, t *testing.T, snapshotter s
 		t.Fatal("expected mounts to have entries")
 	}
 
-	if err = mount.MountAll(mounts, preparing); err != nil {
+	if err = mount.All(mounts, preparing); err != nil {
 		t.Fatal(err)
 	}
 	defer testutil.Unmount(t, preparing)
@@ -279,7 +279,7 @@ func checkSnapshotterStatCommitted(ctx context.Context, t *testing.T, snapshotte
 		t.Fatal("expected mounts to have entries")
 	}
 
-	if err = mount.MountAll(mounts, preparing); err != nil {
+	if err = mount.All(mounts, preparing); err != nil {
 		t.Fatal(err)
 	}
 	defer testutil.Unmount(t, preparing)
@@ -318,7 +318,7 @@ func snapshotterPrepareMount(ctx context.Context, snapshotter snapshot.Snapshott
 		return "", fmt.Errorf("expected mounts to have entries")
 	}
 
-	if err = mount.MountAll(mounts, preparing); err != nil {
+	if err = mount.All(mounts, preparing); err != nil {
 		return "", err
 	}
 	return preparing, nil
@@ -748,7 +748,7 @@ func checkSnapshotterViewReadonly(ctx context.Context, t *testing.T, snapshotter
 	}
 
 	// Just checking the option string of m is not enough, we need to test real mount. (#1368)
-	if err := mount.MountAll(m, viewMountPoint); err != nil {
+	if err := mount.All(m, viewMountPoint); err != nil {
 		t.Fatal(err)
 	}
 

windows/runtime.go

@@ -43,7 +43,7 @@ func init() {
 		ID:   runtimeName,
 		Type: plugin.RuntimePlugin,
 		Init: New,
-		Requires: []plugin.PluginType{
+		Requires: []plugin.Type{
 			plugin.MetadataPlugin,
 		},
 	})