*: add peer VPN support

This commit adds support for defining arbitrary peers that should have
access to the VPN. In k8s, this is accomplished using the new Peer CRD.

cmd/kgctl/showconf.go

@@ -0,0 +1,146 @@
+// Copyright 2019 the Kilo authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/spf13/cobra"
+	"github.com/squat/kilo/pkg/mesh"
+)
+
+func showConf() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "showconf",
+		Short: "Show the WireGuard configuration for a node or peer in the Kilo network",
+		Long:  "",
+	}
+
+	for _, subCmd := range []*cobra.Command{
+		showConfNode(),
+		showConfPeer(),
+	} {
+		cmd.AddCommand(subCmd)
+	}
+
+	return cmd
+}
+
+func showConfNode() *cobra.Command {
+	return &cobra.Command{
+		Use:   "node",
+		Short: "Show the WireGuard configuration for a node in the Kilo network",
+		Long:  "",
+		RunE:  runShowConfNode,
+		Args:  cobra.ExactArgs(1),
+	}
+}
+
+func showConfPeer() *cobra.Command {
+	return &cobra.Command{
+		Use:   "peer",
+		Short: "Show the WireGuard configuration for a peer in the Kilo network",
+		Long:  "",
+		RunE:  runShowConfPeer,
+		Args:  cobra.ExactArgs(1),
+	}
+}
+
+func runShowConfNode(_ *cobra.Command, args []string) error {
+	ns, err := opts.backend.Nodes().List()
+	if err != nil {
+		return fmt.Errorf("failed to list nodes: %v", err)
+	}
+	ps, err := opts.backend.Peers().List()
+	if err != nil {
+		return fmt.Errorf("failed to list peers: %v", err)
+	}
+	hostname := args[0]
+	nodes := make(map[string]*mesh.Node)
+	for _, n := range ns {
+		if n.Ready() {
+			nodes[n.Name] = n
+		}
+	}
+	if len(nodes) == 0 {
+		return errors.New("did not find any valid Kilo nodes in the cluster")
+	}
+	if _, ok := nodes[hostname]; !ok {
+		return fmt.Errorf("did not find any node named %q in the cluster", hostname)
+	}
+
+	peers := make(map[string]*mesh.Peer)
+	for _, p := range ps {
+		if p.Ready() {
+			peers[p.Name] = p
+		}
+	}
+
+	t, err := mesh.NewTopology(nodes, peers, opts.granularity, hostname, mesh.DefaultKiloPort, []byte{}, opts.subnet)
+	if err != nil {
+		return fmt.Errorf("failed to create topology: %v", err)
+	}
+	c, err := t.Conf().Bytes()
+	if err != nil {
+		return fmt.Errorf("failed to generate configuration: %v", err)
+	}
+	fmt.Printf(string(c))
+	return nil
+}
+
+func runShowConfPeer(_ *cobra.Command, args []string) error {
+	ns, err := opts.backend.Nodes().List()
+	if err != nil {
+		return fmt.Errorf("failed to list nodes: %v", err)
+	}
+	ps, err := opts.backend.Peers().List()
+	if err != nil {
+		return fmt.Errorf("failed to list peers: %v", err)
+	}
+	var hostname string
+	nodes := make(map[string]*mesh.Node)
+	for _, n := range ns {
+		if n.Ready() {
+			nodes[n.Name] = n
+			hostname = n.Name
+		}
+	}
+	if len(nodes) == 0 {
+		return errors.New("did not find any valid Kilo nodes in the cluster")
+	}
+
+	peer := args[0]
+	peers := make(map[string]*mesh.Peer)
+	for _, p := range ps {
+		if p.Ready() {
+			peers[p.Name] = p
+		}
+	}
+	if _, ok := peers[peer]; !ok {
+		return fmt.Errorf("did not find any peer named %q in the cluster", peer)
+	}
+
+	t, err := mesh.NewTopology(nodes, peers, opts.granularity, hostname, mesh.DefaultKiloPort, []byte{}, opts.subnet)
+	if err != nil {
+		return fmt.Errorf("failed to create topology: %v", err)
+	}
+	c, err := t.PeerConf(peer).Bytes()
+	if err != nil {
+		return fmt.Errorf("failed to generate configuration: %v", err)
+	}
+	fmt.Printf(string(c))
+	return nil
+}