command/kv: Add prefix option to kv import command

Currently when data is imported via `consul kv import` it overwrites
keys under the root key. Since `consul kv export` can retrieve data for
the given prefix, i.e. part of the KV tree, importing it under root may
be not what users want.

To mirror prefix behavior from export this PR adds prefix feature to the
import command that adds prefix to all keys that are imported.

command/kv/imp/kv_import.go

@@ -10,6 +10,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 
 	"github.com/hashicorp/consul/api"
 	"github.com/hashicorp/consul/command/flags"
@@ -24,10 +25,11 @@ func New(ui cli.Ui) *cmd {
 }
 
 type cmd struct {
-	UI    cli.Ui
-	flags *flag.FlagSet
-	http  *flags.HTTPFlags
-	help  string
+	UI     cli.Ui
+	flags  *flag.FlagSet
+	http   *flags.HTTPFlags
+	help   string
+	prefix string
 
 	// testStdin is the input for testing.
 	testStdin io.Reader
@@ -35,6 +37,7 @@ type cmd struct {
 
 func (c *cmd) init() {
 	c.flags = flag.NewFlagSet("", flag.ContinueOnError)
+	c.flags.StringVar(&c.prefix, "prefix", "", "Key prefix for imported data")
 	c.http = &flags.HTTPFlags{}
 	flags.Merge(c.flags, c.http.ClientFlags())
 	flags.Merge(c.flags, c.http.ServerFlags())
@@ -76,7 +79,7 @@ func (c *cmd) Run(args []string) int {
 		}
 
 		pair := &api.KVPair{
-			Key:   entry.Key,
+			Key:   filepath.Join(c.prefix, entry.Key),
 			Flags: entry.Flags,
 			Value: value,
 		}

command/kv/imp/kv_import_test.go

@@ -70,3 +70,55 @@ func TestKVImportCommand(t *testing.T) {
 		t.Fatalf("bad: expected: baz, got %s", pair.Value)
 	}
 }
+
+func TestKVImportPrefixCommand(t *testing.T) {
+	if testing.Short() {
+		t.Skip("too slow for testing.Short")
+	}
+
+	t.Parallel()
+	a := agent.NewTestAgent(t, ``)
+	defer a.Shutdown()
+	client := a.Client()
+
+	const json = `[
+		{
+			"key": "foo",
+			"flags": 0,
+			"value": "YmFyCg=="
+		}
+	]`
+
+	ui := cli.NewMockUi()
+	c := New(ui)
+	c.testStdin = strings.NewReader(json)
+
+	args := []string{
+		"-http-addr=" + a.HTTPAddr(),
+		"-prefix=" + "sub/",
+		"-",
+	}
+
+	code := c.Run(args)
+	if code != 0 {
+		t.Fatalf("bad: %d. %#v", code, ui.ErrorWriter.String())
+	}
+
+	pair, _, err := client.KV().Get("foo", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if pair != nil {
+		t.Fatalf("bad: expected: nil, got %+v", pair)
+	}
+
+	pair, _, err = client.KV().Get("sub/foo", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if strings.TrimSpace(string(pair.Value)) != "bar" {
+		t.Fatalf("bad: expected: bar, got %s", pair.Value)
+	}
+}

website/content/commands/kv/import.mdx

@@ -21,6 +21,11 @@ Usage: `consul kv import [options] [DATA]`
 
 @include 'http_api_options_server.mdx'
 
+#### KV Import Options
+
+- `-prefix` - Key prefix for imported data. The default value is empty meaning
+  root.
+
 #### Enterprise Options
 
 @include 'http_api_namespace_options.mdx'
@@ -48,3 +53,10 @@ escaping:
 $ consul kv import "$(cat values.json)"
 # Output
 ```
+
+To import under prefix, use `-prefix` option:
+
+```shell-session
+$ cat values.json | consul kv import -prefix=sub/dir/ -
+# Output
+```