command: add skeletons for keys command

command/keys.go

@@ -0,0 +1,97 @@
+package command
+
+import (
+	"flag"
+	"fmt"
+	"github.com/mitchellh/cli"
+	"strings"
+)
+
+// KeysCommand is a Command implementation that handles querying, installing,
+// and removing gossip encryption keys from a keyring.
+type KeysCommand struct {
+	Ui cli.Ui
+}
+
+func (c *KeysCommand) Run(args []string) int {
+	var installKey, useKey, removeKey string
+	var listKeys bool
+
+	cmdFlags := flag.NewFlagSet("keys", flag.ContinueOnError)
+	cmdFlags.Usage = func() { c.Ui.Output(c.Help()) }
+
+	cmdFlags.StringVar(&installKey, "install", "", "install key")
+	cmdFlags.StringVar(&useKey, "use", "", "use key")
+	cmdFlags.StringVar(&removeKey, "remove", "", "remove key")
+	cmdFlags.BoolVar(&listKeys, "list", false, "list keys")
+
+	rpcAddr := RPCAddrFlag(cmdFlags)
+	if err := cmdFlags.Parse(args); err != nil {
+		return 1
+	}
+
+	// Only accept a single argument
+	found := listKeys
+	for _, arg := range []string{installKey, useKey, removeKey} {
+		if found && len(arg) > 0 {
+			c.Ui.Error("Only one of -list, -install, -use, or -remove allowed")
+			return 1
+		}
+		found = found || len(arg) > 0
+	}
+
+	client, err := RPCClient(*rpcAddr)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
+		return 1
+	}
+	defer client.Close()
+
+	if listKeys {
+		return 0
+	}
+
+	if installKey != "" {
+		return 0
+	}
+
+	if useKey != "" {
+		return 0
+	}
+
+	if removeKey != "" {
+		return 0
+	}
+
+	return 0
+}
+
+func (c *KeysCommand) Help() string {
+	helpText := `
+Usage: consul keys [options]
+
+  Manages encryption keys used for gossip messages. Gossip encryption is
+  optional. When enabled, this command may be used to examine active encryption
+  keys in the cluster, add new keys, and remove old ones. When combined, this
+  functionality provides the ability to perform key rotation cluster-wide,
+  without disrupting the cluster.
+
+Options:
+
+  -install=<key>            Install a new encryption key. This will broadcast
+                            the new key to all members in the cluster.
+  -use=<key>                Change the primary encryption key, which is used to
+                            encrypt messages. The key must already be installed
+                            before this operation can succeed.
+  -remove=<key>             Remove the given key from the cluster. This
+                            operation may only be performed on keys which are
+                            not currently the primary key.
+  -list                     List all keys currently in use within the cluster.
+  -rpc-addr=127.0.0.1:8400  RPC address of the Consul agent.
+`
+	return strings.TrimSpace(helpText)
+}
+
+func (c *KeysCommand) Synopsis() string {
+	return "Manages gossip layer encryption keys"
+}

commands.go

@@ -56,6 +56,12 @@ func init() {
 			}, nil
 		},
 
+		"keys": func() (cli.Command, error) {
+			return &command.KeysCommand{
+				Ui: ui,
+			}, nil
+		},
+
 		"leave": func() (cli.Command, error) {
 			return &command.LeaveCommand{
 				Ui: ui,