✨ Add get k3stoken feature

Add new command verb `k3stoken` to `k3d get`
Populate cluster secret field
Add test for `k3d get k3stoken` command
Externalize validable flag `--all`, in anticipation to reuse into `getKubeConfig.go`

cmd/get/get.go

@@ -47,6 +47,7 @@ func NewCmdGet() *cobra.Command {
 	cmd.AddCommand(NewCmdGetCluster())
 	cmd.AddCommand(NewCmdGetNode())
 	cmd.AddCommand(NewCmdGetKubeconfig())
+	cmd.AddCommand(NewCmdGetClusterToken())
 
 	// done
 	return cmd

cmd/get/getClusterToken.go

@@ -0,0 +1,111 @@
+/*
+Copyright © 2020 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 get
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+
+	"github.com/liggitt/tabwriter"
+	cliutil "github.com/rancher/k3d/cmd/util"
+	"github.com/rancher/k3d/pkg/cluster"
+	"github.com/rancher/k3d/pkg/runtimes"
+	k3d "github.com/rancher/k3d/pkg/types"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+type clusterTokenFlags struct {
+	validableFlags cliutil.ValidableFlags
+	noHeader       bool
+}
+
+// NewCmdGetClusterToken returns a new cobra command
+func NewCmdGetClusterToken() *cobra.Command {
+
+	getClusterTokenFlags := clusterTokenFlags{}
+
+	// create new command
+	cmd := &cobra.Command{
+		Use:   "k3stoken [CLUSTER [CLUSTER [...]] | --all]",
+		Short: "Get cluster token",
+		Long:  `Get k3s cluster token.`,
+		Args: func(cmd *cobra.Command, args []string) error {
+			return cliutil.ValidateClusterNameOrAllFlag(args, getClusterTokenFlags.validableFlags)
+		},
+		Run: func(cmd *cobra.Command, args []string) {
+			var clusters []*k3d.Cluster
+			var err error
+
+			// generate list of clusters
+			if getClusterTokenFlags.validableFlags.All {
+				clusters, err = cluster.GetClusters(runtimes.SelectedRuntime)
+				if err != nil {
+					log.Fatalln(err)
+				}
+			} else {
+				for _, clusterName := range args {
+					retrievedCluster, err := cluster.GetCluster(&k3d.Cluster{Name: clusterName}, runtimes.SelectedRuntime)
+					if err != nil {
+						log.Fatalln(err)
+					}
+					clusters = append(clusters, retrievedCluster)
+				}
+			}
+
+			// pretty print secret
+			printSecret(clusters, getClusterTokenFlags.noHeader)
+		},
+	}
+
+	// add flags
+	cmd.Flags().BoolVarP(&getClusterTokenFlags.validableFlags.All, "all", "a", false, "Get k3s token from all existing clusters")
+	cmd.Flags().BoolVar(&getClusterTokenFlags.noHeader, "no-headers", false, "Disable headers")
+
+	// done
+	return cmd
+}
+
+func printSecret(clusters []*k3d.Cluster, headersOff bool) {
+
+	tabwriter := tabwriter.NewWriter(os.Stdout, 6, 4, 3, ' ', tabwriter.RememberWidths)
+	defer tabwriter.Flush()
+
+	if !headersOff {
+		headers := []string{"CLUSTER", "SECRET"}
+		_, err := fmt.Fprintf(tabwriter, "%s\n", strings.Join(headers, "\t"))
+		if err != nil {
+			log.Fatalln("Failed to print headers")
+		}
+	}
+
+	// alphabetical sort by cluster name
+	sort.Slice(clusters, func(i, j int) bool {
+		return clusters[i].Name < clusters[j].Name
+	})
+
+	for _, cluster := range clusters {
+		fmt.Fprintf(tabwriter, "%s\t%s\n", cluster.Name, string(cluster.Secret))
+	}
+}

cmd/util/args.go

@@ -0,0 +1,44 @@
+/*
+Copyright © 2020 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 util
+
+import (
+	"fmt"
+)
+
+// struct describe flags which could be validate thanks to this file's functions
+type ValidableFlags struct {
+	All bool
+}
+
+// ValidateClusterNameOrAllFlag checks, if cluster name or --all arg is set
+func ValidateClusterNameOrAllFlag(args []string, flagStruct ValidableFlags) error {
+
+	clusterNamePresent := len(args) > 0
+	getAllFlagPresent := flagStruct.All
+
+	// xor : provide cluster name or all flags
+	if clusterNamePresent != getAllFlagPresent {
+		return nil
+	}
+	return fmt.Errorf("Need to specify one or more cluster names *or* set `--all` flag")
+}

pkg/cluster/cluster.go

@@ -442,6 +442,12 @@ func populateClusterFieldsFromLabels(cluster *k3d.Cluster) error {
 			}
 		}
 
+		// get k3s cluster's secret
+		if cluster.Secret == "" {
+			if secretToken, ok := node.Labels[k3d.SecretLabelName]; ok {
+				cluster.Secret = secretToken
+			}
+		}
 	}
 
 	return nil

tests/common.sh

@@ -107,3 +107,8 @@ check_registry() {
 check_volume_exists() {
   docker volume inspect "$1" >/dev/null 2>&1
 }
+
+check_cluster_token_exist() {
+  [ -n "$EXE" ] || abort "EXE is not defined"
+  $EXE get k3stoken "$1" >/dev/null 2>&1
+}

tests/test_basic.sh

@@ -16,6 +16,10 @@ check_cluster_count 2
 info "Checking we have access to both clusters..."
 check_clusters "c1" "c2" || failed "error checking cluster"
 
+info "Check k3s token retrieval"
+check_cluster_token_exist "c1" || failed "could not find cluster token c1"
+check_cluster_token_exist "c2" || failed "could not find cluster token c2"
+
 info "Deleting clusters..."
 $EXE delete cluster c1 || failed "could not delete the cluster c1"
 $EXE delete cluster c2 || failed "could not delete the cluster c2"