Merge branch 'pr-93'

* pr-93:
  Add option to fetch Docker-Content-Digest
  Fix typo

README.md

@@ -11,6 +11,7 @@ Docker registry v2 command line client.
     + [Auth](#auth)
     + [List Repositories and Tags](#list-repositories-and-tags)
     + [Get a Manifest](#get-a-manifest)
+    + [Get the Digest](#get-the-digest)
     + [Download a Layer](#download-a-layer)
     + [Delete an Image](#delete-an-image)
     + [Vulnerability Reports](#vulnerability-reports)
@@ -49,6 +50,7 @@ AUTHOR:
 
 COMMANDS:
      delete, rm       delete a specific reference of a repository
+     digest           get the digest
      layer, download  download a layer for the specific reference of a repository
      list, ls         list all repositories
      manifest         get the json manifest for the specific reference of a repository
@@ -105,7 +107,7 @@ latest
 stable
 ```
 
-### Get a Manifest
+## Get a Manifest
 
 ```console
 $ reg manifest htop
@@ -126,6 +128,12 @@ $ reg manifest htop
  }
 ```
 
+## Get the Digest
+```console
+$ reg digest htop
+sha256:791158756cc0f5b27ef8c5c546284568fc9b7f4cf1429fb736aff3ee2d2e340f
+```
+
 ### Download a Layer
 
 ```console

digest.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/genuinetools/reg/repoutils"
+	"github.com/urfave/cli"
+)
+
+var digestCommand = cli.Command{
+	Name:  "digest",
+	Usage: "get the Docker-Content-Digest",
+	Action: func(c *cli.Context) error {
+		if len(c.Args()) < 1 {
+			return fmt.Errorf("pass the name of the repository")
+		}
+
+		repo, ref, err := repoutils.GetRepoAndRef(c.Args()[0])
+		if err != nil {
+			return err
+		}
+
+		var digest interface{}
+		digest, err = r.Digest(repo, ref)
+		if err != nil {
+			return err
+		}
+
+		b, err := json.MarshalIndent(digest, " ", "  ")
+		if err != nil {
+			return err
+		}
+
+		fmt.Println(string(b))
+
+		return nil
+	},
+}

main.go

@@ -67,6 +67,7 @@ func main() {
 
 	app.Commands = []cli.Command{
 		deleteCommand,
+		digestCommand,
 		layerCommand,
 		listCommand,
 		manifestCommand,

manifest.go

@@ -14,7 +14,7 @@ var manifestCommand = cli.Command{
 	Flags: []cli.Flag{
 		cli.BoolFlag{
 			Name:  "v1",
-			Usage: "force the version of the manifest retreived to v1",
+			Usage: "force the version of the manifest retrieved to v1",
 		},
 	},
 	Action: func(c *cli.Context) error {