Add helpers to create errdef errors

Instead of having to create a bunch of custom error types that are doing
nothing but wrapping another error in sub-packages, use a common helper
to create errors of the requested type.

e.g. instead of re-implementing this over and over:

```go
type notFoundError struct {
  cause error
}

func(e notFoundError) Error() string {
  return e.cause.Error()
}

func(e notFoundError) NotFound() {}

func(e notFoundError) Cause() error {
  return e.cause
}
```

Packages can instead just do:

```
  errdefs.NotFound(err)
```

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/daemon/archive.go b/daemon/archive.go
index c52d3b8509..ddc4b572bd 100644
--- a/daemon/archive.go
+++ b/daemon/archive.go
@@ -5,6 +5,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/docker/docker/api/errdefs"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/pkg/archive"
@@ -54,7 +55,7 @@ func (daemon *Daemon) ContainerCopy(name string, res string) (io.ReadCloser, err
 
 	// Make sure an online file-system operation is permitted.
 	if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
-		return nil, systemError{err}
+		return nil, errdefs.System(err)
 	}
 
 	data, err := daemon.containerCopy(container, res)
@@ -65,7 +66,7 @@ func (daemon *Daemon) ContainerCopy(name string, res string) (io.ReadCloser, err
 	if os.IsNotExist(err) {
 		return nil, containerFileNotFound{res, name}
 	}
-	return nil, systemError{err}
+	return nil, errdefs.System(err)
 }
 
 // ContainerStatPath stats the filesystem resource at the specified path in the
@@ -78,7 +79,7 @@ func (daemon *Daemon) ContainerStatPath(name string, path string) (stat *types.C
 
 	// Make sure an online file-system operation is permitted.
 	if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
-		return nil, systemError{err}
+		return nil, errdefs.System(err)
 	}
 
 	stat, err = daemon.containerStatPath(container, path)
@@ -89,7 +90,7 @@ func (daemon *Daemon) ContainerStatPath(name string, path string) (stat *types.C
 	if os.IsNotExist(err) {
 		return nil, containerFileNotFound{path, name}
 	}
-	return nil, systemError{err}
+	return nil, errdefs.System(err)
 }
 
 // ContainerArchivePath creates an archive of the filesystem resource at the
@@ -103,7 +104,7 @@ func (daemon *Daemon) ContainerArchivePath(name string, path string) (content io
 
 	// Make sure an online file-system operation is permitted.
 	if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
-		return nil, nil, systemError{err}
+		return nil, nil, errdefs.System(err)
 	}
 
 	content, stat, err = daemon.containerArchivePath(container, path)
@@ -114,7 +115,7 @@ func (daemon *Daemon) ContainerArchivePath(name string, path string) (content io
 	if os.IsNotExist(err) {
 		return nil, nil, containerFileNotFound{path, name}
 	}
-	return nil, nil, systemError{err}
+	return nil, nil, errdefs.System(err)
 }
 
 // ContainerExtractToDir extracts the given archive to the specified location
@@ -131,7 +132,7 @@ func (daemon *Daemon) ContainerExtractToDir(name, path string, copyUIDGID, noOve
 
 	// Make sure an online file-system operation is permitted.
 	if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
-		return systemError{err}
+		return errdefs.System(err)
 	}
 
 	err = daemon.containerExtractToDir(container, path, copyUIDGID, noOverwriteDirNonDir, content)
@@ -142,7 +143,7 @@ func (daemon *Daemon) ContainerExtractToDir(name, path string, copyUIDGID, noOve
 	if os.IsNotExist(err) {
 		return containerFileNotFound{path, name}
 	}
-	return systemError{err}
+	return errdefs.System(err)
 }
 
 // containerStatPath stats the filesystem resource at the specified path in this