add debug functionality to get current loadbalancer config

cmd/debug/debug.go

@@ -0,0 +1,91 @@
+/*
+Copyright © 2020-2021 The k3d Author(s)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package debug
+
+import (
+	"fmt"
+
+	"github.com/rancher/k3d/v4/pkg/client"
+	"github.com/rancher/k3d/v4/pkg/runtimes"
+	"github.com/rancher/k3d/v4/pkg/types"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
+)
+
+// NewCmdDebug returns a new cobra command
+func NewCmdDebug() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:    "debug",
+		Hidden: true,
+		Short:  "Debug k3d cluster(s)",
+		Long:   `Debug k3d cluster(s)`,
+		Run: func(cmd *cobra.Command, args []string) {
+			if err := cmd.Help(); err != nil {
+				log.Errorln("Couldn't get help text")
+				log.Fatalln(err)
+			}
+		},
+	}
+
+	cmd.AddCommand(NewCmdDebugLoadbalancer())
+
+	return cmd
+}
+
+func NewCmdDebugLoadbalancer() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "loadbalancer",
+		Aliases: []string{"lb"},
+		Short:   "Debug the loadbalancer",
+		Long:    `Debug the loadbalancer`,
+		Run: func(cmd *cobra.Command, args []string) {
+			if err := cmd.Help(); err != nil {
+				log.Errorln("Couldn't get help text")
+				log.Fatalln(err)
+			}
+		},
+	}
+
+	cmd.AddCommand(&cobra.Command{
+		Use:  "get-config",
+		Args: cobra.ExactArgs(1), // cluster name
+		Run: func(cmd *cobra.Command, args []string) {
+			c, err := client.ClusterGet(cmd.Context(), runtimes.SelectedRuntime, &types.Cluster{Name: args[0]})
+			if err != nil {
+				log.Fatalln(err)
+			}
+
+			lbconf, err := client.GetLoadbalancerConfig(cmd.Context(), runtimes.SelectedRuntime, c)
+			if err != nil {
+				log.Fatalln(err)
+			}
+			yamlized, err := yaml.Marshal(lbconf)
+			if err != nil {
+				log.Fatalln(err)
+			}
+			fmt.Println(string(yamlized))
+		},
+	})
+
+	return cmd
+}

cmd/root.go

@@ -34,6 +34,7 @@ import (
 
 	"github.com/rancher/k3d/v4/cmd/cluster"
 	cfg "github.com/rancher/k3d/v4/cmd/config"
+	"github.com/rancher/k3d/v4/cmd/debug"
 	"github.com/rancher/k3d/v4/cmd/image"
 	"github.com/rancher/k3d/v4/cmd/kubeconfig"
 	"github.com/rancher/k3d/v4/cmd/node"
@@ -116,6 +117,7 @@ func init() {
 	rootCmd.AddCommand(image.NewCmdImage())
 	rootCmd.AddCommand(cfg.NewCmdConfig())
 	rootCmd.AddCommand(registry.NewCmdRegistry())
+	rootCmd.AddCommand(debug.NewCmdDebug())
 
 	rootCmd.AddCommand(&cobra.Command{
 		Use:   "version",

pkg/client/loadbalancer.go

@@ -22,13 +22,17 @@ THE SOFTWARE.
 package client
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"io/ioutil"
 	"strings"
 
 	"github.com/rancher/k3d/v4/pkg/runtimes"
+	"github.com/rancher/k3d/v4/pkg/types"
 	k3d "github.com/rancher/k3d/v4/pkg/types"
 	log "github.com/sirupsen/logrus"
+	"sigs.k8s.io/yaml"
 )
 
 // UpdateLoadbalancerConfig updates the loadbalancer config with an updated list of servers belonging to that cluster
@@ -70,3 +74,38 @@ func UpdateLoadbalancerConfig(ctx context.Context, runtime runtimes.Runtime, clu
 
 	return nil
 }
+
+func GetLoadbalancerConfig(ctx context.Context, runtime runtimes.Runtime, cluster *k3d.Cluster) (*types.LoadbalancerConfig, error) {
+
+	if cluster.ServerLoadBalancer == nil {
+		for _, node := range cluster.Nodes {
+			if node.Role == types.LoadBalancerRole {
+				var err error
+				cluster.ServerLoadBalancer, err = NodeGet(ctx, runtime, node)
+				if err != nil {
+					return nil, err
+				}
+			}
+		}
+	}
+
+	reader, err := runtime.ReadFromNode(ctx, types.DefaultLoadbalancerConfigPath, cluster.ServerLoadBalancer)
+	if err != nil {
+		return &k3d.LoadbalancerConfig{}, err
+	}
+	defer reader.Close()
+
+	file, err := ioutil.ReadAll(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	file = bytes.Trim(file[512:], "\x00") // trim control characters, etc.
+
+	currentConfig := &types.LoadbalancerConfig{}
+	if err := yaml.Unmarshal(file, currentConfig); err != nil {
+		return nil, err
+	}
+
+	return currentConfig, nil
+}

pkg/types/types.go

@@ -426,3 +426,23 @@ type RegistryExternal struct {
 	Host     string `yaml:"host" json:"host"`
 	Port     string `yaml:"port" json:"port"`
 }
+
+/*
+ * Loadbalancer
+ */
+
+/* LoadbalancerConfig defines the coarse file structure to configure the k3d-proxy
+ * Example:
+ * ports:
+ * 	1234.tcp:
+ * 		- k3d-k3s-default-server-0
+ * 		- k3d-k3s-default-server-1
+ * 	4321.udp:
+ * 		- k3d-k3s-default-agent-0
+ * 		- k3d-k3s-default-agent-1
+ */
+type LoadbalancerConfig struct {
+	Ports map[string][]string `yaml:"ports"`
+}
+
+const DefaultLoadbalancerConfigPath = "/etc/confd/portmap.yaml"